The Great Structures in Architecture : From Antiquity to Baroque (Advances in Architecture)

The Great Structures in Architecture Antiquity to Baroque

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International Series on Adv an ces in Architecture ances Objectives The field of architecture has experienced considerable advances in the last few years, many of them connected with new methods and processes, the development of faster and better computer systems and a new interest in our architectural heritage. It is to bring such advances to the attention of the international community that this book series has been established. The object of the series is to publish state-of-the-art information on architectural topics with particular reference to advances in new fields, such as virtual architecture, intelligent systems, novel structural forms, material technology and applications, restoration techniques, movable and lightweight structures, high rise buildings, architectural acoustics, leisure structures, intelligent buildings and other original developments. The Advances in Architecture series consists of a few volumes per year, each under the editorship - by invitation only - of an outstanding architect or researcher. This commitment is backed by an illustrious Editorial Board. Volumes in the Series cover areas of current interest or active research and include contributions by leaders in the field.

Managing Editor

Honorary Editor

Honorary Editor

F. Escrig Escuela de Arquitectura Universidad de Sevilla Spain

C. A. Brebbia Wessex Institute of Technology Ashurst Lodge, Ashurst Southampton UK

P. R. Vazquez Fuentes 170 Pedregal de San Angel 01900 Mexico D.E. Mexico

Associate Editors C. Alessandri

W. P. De Wilde

M. Majowiecki

University of Ferrara Italy

Free University of Brussel Belgium

University of Bologna Italy

F. Butera

C. Gantes

S. Sánchez-Beitia

DI Tec, Politecnico di Milano Italy

National Technical University of Athens Greece

University of the Basque Country, Spain

J. Chilton

K. Ghavami

J. J. Sendra

University of Nottingham UK

Pontifica Univ Catolica Brazil

Universidad de Sevilla Spain

G. Croci

K. Ishii

M. Zador

Istituto di Tecnica delle Costruzioni Italy

Yokohama Japan

Technical University of Budapest Hungary

A. de Naeyer

W. Jäger

R. Zarnic

University of Ghent Belgium

Technical University of Dresden Germany

University of Ljubljana Slovenia

The Great Structures in Architecture Antiquity to Baroque

F. Escrig Universidad de Sevilla, Spain

The Great Structures in Architecture Antiquity to Baroque

Series: Advances in Architecture, Vol. 22 F. Escrig

Published by

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CONTENTS

INTRODUCTION ........................................................................................................................................ vii

Chapter 1:

STONES RESTING ON EMPTY SPACE............................................................................1

Chapter 2:

THE INVENTION OF THE DOME.....................................................................................21

Chapter 3:

THE HANGING DOME......................................................................................................45

Chapter 4:

THE RIBBED DOME .........................................................................................................65

Chapter 5:

A PLANIFIED REVENGE. UNDER THE SHADOW OF BRUNELLESCHI .......................96

Chapter 6:

THE CENTURY OF THE GREAT ARCHITECTS ...........................................................120

Chapter 7:

THE OMNIPRESENT SINAN..........................................................................................150

Chapter 8:

EVEN FURTHER ............................................................................................................168

Chapter 9:

THE PERFECT SYMBIOSES FORM-FUNCTION IN THE HIGH BAROQUE ARCHITECTURE ............................................................................................................180

Chapter 10:

SCENOGRAPHICAL ARCHITECTURE OF THE 18

Chapter 11:

THE VIRTUAL ARCHITECTURE OF THE RENAISSANCE AND THE BAROQUE ......................................................................................................................243

TH

CENTURY.................................209

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INTRODUCTION

I have always found amazing the fact that someone in the past spent his time piling stones up to mark or to delimit an area. But I get even more astonished when I come to think that somebody dared to live within that pile of stones and, in addition, felt safer inside it than outside. That leads me to the conclusion that in those days people had to have a great faith in their own skill to take shelter in the shade of a wall of rough stones and that they fully relied on the physical laws to dare to live under a slab canopy. You could think that to build a dolmen, people only needed enough energy to move the huge stones it was made of, its stability being guaranteed by the inertia of those colossal masses. But when someone first succeeded in making a ceiling of pebbles, supported by a material as weak as mud, that represented a step forward as great as the control of fire. Nevertheless, that must have happened so long ago that no mythology tells about a God owning the power to keep stones floating in the air. The Bible considers the existence of domes so obvious that not only does it not mention it, but when an arch or a temple is to be made, wooden architraves are used, choosing the noble building way instead of the popular brick based architecture. Neither do the Babylonian legends mention anything referring to architecture. And the Egyptians either, since they deified the human architect that constructed Zoser’s pyramids. Greek mythology makes reference to all the forces of nature and to all the human passions and liking, but not to architecture. The Nordic ancient cultures, more primitive, can deify the axe because it is an instrument for wood building, which they never do with architecture itself. And we could go on with the Oriental mythologies with similar results. Why does something so important stay outside the consideration of men? In my previous book Towers and Domes I advanced some hypotheses, but I must insist on the instrumental character of the domestic architecture and on the symbolic character of the great architecture as a means to achieve other objectives.

We could also think that architecture is something so recent that it appeared when the legendary corpus of tradition was already finished, so that everything to be added to tradition would show an unmistakably human character. In case that is right, this book tries to start from the early origins without fearing to ignore undocumented precedents, but the historical sequence reveals itself as tricky. In any case, what is left is the proof of the existence of these works, which have evolved in a progressive and sequential order as mentioned. The story that I tell, which starts in antiquity and finishes in the Baroque in this first volume, and reaches to the present time in the volume to follow, intends to reflect on the great adventure of architecture. Every matter is open to opinions and everything is objectionable. That is settled. But from the viewpoint of someone who practices architecture, this text will possibly serve to better understand the monuments, to get closer to them and find out whether they should be conserved or modified, and to be humbler when thinking that our tools are all-powerful. If we realised that our advantage is based in the fact that we have new materials invented by chemists and that in using sun-cooked bricks our results would not be different to those of Babylonian craftsmen, we would be more modest. Instead of committing outrages favoured by the resistance of concrete and steel, we could study the importance of the forms and its optimisation.

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Stones Resting on Empty Space

Chapter 1. STONES RESTING ON EMPTY SPACE

Huge limestone rocky formations that end on the Mediterranean coasts penetrate the continent, shaping steep and stony landscapes. Among them sandy, usually dry waterbeds, wind their way down and lead the water of rivers that have their source far inland. Some of the oldest civilisations bloomed in those rocky deserts and have survived keeping themselves on the thin layer of earth resulting from the action of weather over the stones. This was a world of shepherds in which the kindness of the weather allowed them to be partially sedentary, a world of fishermen and navigators whose knowledge of the Earth was confined to the rocky shores and the silky beaches, a world of soldiers that snatched out of their neighbours what their fields lacked, a world of explorers in pursuit of paradises that inspired their epic poets. The Palaeolithic civilisation was based on very limited resources and a slowly made culture zealously passed on from one generation to the next. In other countries other great civilisations were growing around true orchards watered by mighty rivers or on vast plains. But the Mediterranean people had to struggle for every inch of ground to sow their seeds, clearing the surface of stones, terracing the steep slopes, or carrying back to the terraces the little earth that had slipped to the bottom of the ravines, and utilising every source of water available to water the grapevines, the olive, the almond and the fig trees. It was in this poor but well used space where one of the greater structural revolutions took place. There were few woods and the little wood of use for the construction, such as that of pine trees, was as valuable as a treasure, though the climate made it prone to fire and rotting. Reeds are good as planking and are more resistant, and the adobe and the earth building provided stability and protection. Some types of impermeable clay are good as layers on the reed covers and, on occasions, an incomplete firing provides rudimentary tiles not much better than mud walls.

In any case, the abounding lime is good to make every material impermeable and lend it cohesion. The typical Mediterranean house was at first no more than a modest cabin made of flat walls with small holes blocked up with boards as windows and a flat reed or board roof. The prismatic modules could be attached to each other to make better use of walls. In this way a city was born, growing along more or less straight streets with walls like fish backbones. The doors opened into streets along which ran traffic, waste and people, who found in them a public and open place as an extension of the small cubicles they lived in. The cattle shared the streets with trade, policy and culture. This primitive Mediterranean house did not have an interior courtyard. That is a later invention whose origin can be found in the country houses related to farming and cattle farming. This form of construction is very similar to those developed by other civilisations since it was almost spontaneous. At the same time there was a more complex and permanent architecture, that made of stones. This constructive system is based on the ease of limestone blocks to fragment in angular and flat pieces, easy to pile up and very steady once piled. Walls can be made of stones as well as primitive tiles. But although the walls admit a certain sloping, the problem to close convex enclosures must be solved by means of wooden beams. The great structural discovery was the horizontal covering by means of the stone advance. The result has been called false vault, or false dome, as it could have been called falsely lintelled. All of them are negative terms that in a certain way reveal that language apostatises regrets of a great cultural contribution. The English people refer to “corbelled” in a positive way, although they rarely used this type of construction, which should be called “advanced course domes”. We are not talking about megalithic monuments, made of great granite or sandstone blocks such as the Cave of Menga, the Temple at Stonehenge or the Minorca’s Taulas. We are talking about structures mostly made

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The Great Structures in Architecture

Fig. 1.1. Schematic section of the Cave of El Romeral, in Antequera (Escrig).

of rough stone pieces light enough to be moved without the help of great tools, that is to say rubble work. Near Menga, in Antequera, is the Cave of El Romeral, one of the most perfect constructions of advanced course domes. Dating approximately from 4500 years ago it is a burial mound. Its central room is 5.20 m in diameter and 3.9 m high. The headstone consists of a stone of great size very like other archaic works, and the whole construction, that is completed with an access corridor and a smaller chamber, is covered by a mound of earth which has helped to preserve it in perfect condition. Fig. 1.1 shows a general view of the monument, whereas Fig. 1.2 shows a sectional view in its present state. The pictures of Fig. 1.3 to 1.6 give an idea of the perfection of the bond that has recently been partially restored. Many are the domes made from this model scattered all over Europe as proof of the capacity of navigators, explorers and soldiers to spread culture and techniques. In Portugal there are vast number of tombs with corridors made in a simpler way with great slabs (Fig. 1.7).

Minorca has impressive megalithic vaults in constructions reaching two floors, as Naveta del Tudons (Figs. 1.8 and 1.9), that does not have a wholly rounded cover because its constructors just let the walls tilt inwards, shortening the span of the closing stones. This happened about 1500 BC, a thousand years after El Romeral; the Mediterranean zone abounds in this type of construction dating from the same time. At Los Millares (Fig. 1.10), at Ontiveros, Matarrubilla or La Pastora (Fig. 1.11) in the El Aljarafe zone in Seville, as well as in the South of France, in the Mediterranean Italian islands, and in general in every country under the “calcareous curse”, this system has remained until today. Nevertheless, about 1350 BC, this technique was developed in the Peloponnesus to such an extent that perfect domes of advanced courses could be built. The Treasure of Atreo had the greatest dome ever constructed until it was surpassed by Agrippa’s Pantheon a thousand years later. The Treasure of Atreo,

Fig. 1.2. Plan and section of the Cave of El Romeral, in Antequera (Mata Carriazo).

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Stones Resting on Empty Space

Fig. 1.3. Corridor of access to the Cave of El Romeral, in Antequera (Escrig).

Fig. 1.4. Door of access to the main chamber of the Cave of El Romeral, in Antequera (Escrig).

Fig. 1.5. Stone disposition of the main chamber of the Cave of El Romeral, in Antequera (Escrig).

Fig. 1.6. Access to the second chamber of the Cave of El Romeral, and covering slab (Escrig).

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The Great Structures in Architecture

Fig. 1.7. Domed tombs sketches from Portugal (Fletcher).

Fig. 1.11. Cave of Ontiveros, in Valencina near Seville (Escrig).

Fig. 1.8. Outer view of Naveta dels Tudons, in Minorca (Salvat).

Fig. 1.9. Inner view of Naveta dels Tudons, in Minorca (Salvat).

also named Agamemnon’s Tomb, in Mycenae, is a circular enclosure 14.6 m in diameter and 13.5 m high. Its access through a brief covered gallery and a passage between embankments, lends it a moving magnificence. The cross section is almost parabolic although its pointing in the headstone reveals an attempt to improve its stability as if it was an ogival profile (Fig.1.12). The vault is made of carved stones of almost one tonne in a perfect bond that reveals either a great command of stereotomy techniques or a later carving of its inner part to level its surface and to get it decorated (Fig. 1.13). The curved lintel and the discharging arch prove a good knowledge of building problems (Fig. 1.14). The covering mound of earth makes it stable and probably served to contain the ramps along which the stones were lifted (Fig. 1.15). At this point one has to wonder what was the static working of this system of stones bonding over empty space and why, though being structurally correct, it was not included in the later cultured architecture, even more since this system was not surpassed by any other made up of stones until the French Romanesque vaults.

Fig. 1.10a and b. Tholos of Los Millares in Almeria.

4

In Ref. 26 Syrmakezis analyses some recent Greek constructions and makes a detailed exposition of its balance. For a linear construction with prismatic blocks see (Fig. 1.16), and the following equations:

Stones Resting on Empty Space

Fig. 1.12. Schematic detail from the Treasure of Atreo, in Mycenae (Escrig).

v

∑ W (a i =1

i

v +1

− βi) ≤ 0

bi 2

β i = ai +

[1.1] [1.2]

v

a v +1 =

∑β W i =1 v

i

∑W i =1

Fig. 1.13. Detail of the access to the main chamber of the Treasure of Atreo, including the lintel and the discharging arch.

i

β v +1 = a v +1 + av+1 =

[1.3]

i

1 v ∑ βi v i =1

bv +1 2

[1.4]

[1.5]

This does not depend on the height of blocks (Figs. 1.17 and 1.18). In this case all the stones are identical.

Fig. 1.14. Stone bound of the dome of the Treasure of Atreo, in Mycenae (Escrig).

Fig. 1.15. Entrance and covering mound of the Treasure of Atreo (Escrig).

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The Great Structures in Architecture

Fig. 1.16. Balance scheme of the prismatic blocks projection (Syrmakezis).

av +1 − av =

b 2v

[1.6]

b a2 − a1 = , 2

a3 − a2 =

b , 4

a4 − a3 =

b 6

[1.7]

In case we considered decreasing rows instead straight rows, being d and and hi constant (Fig. 1.19), the formula becomes v

a v +1 =

b + 2

∑a d i

i =1 v

∑d i =1

i

[1.8] i

d i = d + i ⋅ Δd

[1.9] v

a v +1 =

Figs. 1.17 and 1.18. Independence of the projection with regards to the thickness of the pieces, for the projections balance analysis (Syrmakezis).

v

d ∑ ai + Δd ∑ iai

b i =1 + 2 ⋅ i =1 2 2vd + v (v + 1) Δd

[1.10]

Which means that in case

d1 = Δd ,..., d 2 = 2Δd ,.... v

av +1 =

∑ ia

i b + 2 ⋅ i =1 v(v + 1) 2

[1.11]

Which leads to

a v +1 − a v =

b v

[1.12]

Meaning that

b a2 − a1 = , 2

b a3 − a2 = , 3

a4 − a3 =

b 4

[1.13]

If as it happens in many mounds, the courses have a back counterweight made of earth or rubble (Fig. 1.20) the formulas [1.1] to [1.5] become

6

Fig. 1.19. Scheme of the projection with a decreasing number of blocks (Syrmakezis).

Stones Resting on Empty Space

Fig. 1.20. Balance of projections made of isolated blocks, balanced with a rear load (Syrmakezis).

v

∑ W (a i

i =1

v

v +1 − β i ) + ∑ W ' i ( a v +1 − β ' i ) ≤ 0

=

a

bi 2

[1.16]

∑β W +∑β ' W'

av+1 = i=1

i

i

i

i =1

i

[1.18]

v

∑(W +W′ ) i

i =1

Which being

1 2

b i = b becomes

v (a v + b) 2 − ∑ ai2 i =1 v

[1.19]

v ( a v + b) − ∑ a i i =1

If starting from this premise, we wanted to face the real problem of the Treasure of Atreo (Fig. 1.21) without taking into account the stabilising earth weight.

v

rv +1

1 = cosϕ

∑β W i =1 v

i

i

∑W i =1

i =1

i

i

i =1

i

' Wi '

[1.23]

v

∑ (W + W ′ ) i =1

i

i

2 senϕ R' i2 + R' i r' i + r' i2 β i' = 3 ϕ Ri ' + r' i

[1.24]

Wi = yπ ϕ ( Ri′ 2 + ri ′ 2 ) hi

[1.25]

Being

i

v

a v +1 =

rv +1

1 = cosϕ

∑ β W +∑ β

[1.17]

v

v

v

v

+

i

If we counted on the existence of the back counterweight

[1.15]

W 'i = yπ ⋅ d i hi (av + bv − ai − bi ) i

[1.14]

i =1

Wi = y ⋅ bi d i hi

β

Fig. 1.21. Scheme for the study of the balance of circular shaped decreasing stone courses (Syrmakezis).

[1.20]

i

2 senϕ Ri2 + Ri ri + ri 2 βi = 3 ϕ Ri + ri

[1.21]

Wi = yϕ hi ( Ri2 + ri 2 )

[1.22]

ri ′ = ri + bi

[1.26]

Ri′ = rv + bv

[1.27]

If we knew therefore the size of every stone that makes up the thirty-three advanced courses, its density and the density and height of the filling material we would directly obtain from the previous expressions the optimal profile of the vault. In Ref. 25 Symakezis has developed a calculation program that from the previous parameters and including the stones resistance to flexo-compression and to cutting effort, allows us to develop the stable profile considering the static and structural stability, though the table only reaches a height of 4 m and a span of 5 m, as is shown in Fig. 1.22, where the stable profiles appear in shade. If we consider that the voussoirs are carved in a wedge shape and therefore the problem of the flexion or the cutting one are of no importance, we will be able to change the scale to fit the size of the Treasure of Atreo, locating its profile in the zone of suggested stability of Fig. 1.23.

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The Great Structures in Architecture

Fig. 1.22. Calculation of the stable profiles for domes of projected stones (Syrmakezis).

Fig. 1.25.a and b. Different outer views of a present Cretan dome (Syrmakezis).

Fig. 1.23. Scheme or the stability zone and the profile position of the Treasure of Atreo (Escrig).

Fig. 1.24. Analysis of present Cretan constructions. Typical section (Syrmakezis).

Syrmakezis has analysed Cretan constructions dating from the beginning of the XXth century, which are infinitely more modest and made of rough stones fitting also the profiles in the mentioned stable limits (Fig. 1.24).

8

Fig. 1.25.c and d. Different inner views of a present Cretan dome (Syrmakezis).

Stones Resting on Empty Space

Fig. 1.26. Different types of shepherd huts from the Levantine Maestrazgo, in Castellon. (García Lisón)

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The Great Structures in Architecture

Fig. 1.27a, b, c, d and e. Different views of some shepherd huts in Castellón (Escrig).

10

Stones Resting on Empty Space

Fig. 1.28a, b and c. Different views of the inner stone disposition of some shepherd huts (Escrig).

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The Great Structures in Architecture

Fig. 1.29a and b. Present views of the Italian Trulli.

12

Stones Resting on Empty Space

Fig. 1.29c. General view of Alberobello.

Fig. 1.30. The Trulli as a tourist attraction, in Alberobello.

Fig. 1.25 shows different building aspects wherein even the superposed lintels in substitution of the discharging arches can be seen. The disappearance of this structural type that has countless advantages seems inexplicable:

a) b) c) d) e)

Admits stones without carving. Construction without need for a temporary support. No need for horizontal thrust. Neither flexion nor cracking zones. Possibility of openings in the surface without altering its tensional state.

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The Great Structures in Architecture

SECONDARY FORM

Fig. 1.34a. Group of Bories in Sarlat, in the French region of Perigord (Escrig).

COMPOSED FORM

Fig. 1.31. Evolution of the Trulli (Vernice). Fig. 1.34b. Inner aspect of a Borie, a stone cabin, in Sarlat (Escrig).

Fig. 1.32. Stonehenge aereal view in Salisbury in England.

Fig. 1.33. Oratory of Gallarus, in Ireland.

14

Fig. 1.35a. and 1.35b. Recent project to build a Borie (Escrig).

Stones Resting on Empty Space

Its hypothetical disadvantages, such as too much thickness and weight and its high camber, do not seem enough reasons to think of it as obsolescent, even more considering that in the Treasure we find the first pointed arch, preceding the exquisite medieval works. The main thing is that in the time of maximum splendour of their culture, Greek people, though having to hand these examples, possibly by the hundreds, preferred a much more primitive system with column and lintel or strut and brace, whose vegetal precedents they did not try to hide. Fortunately for the advanced courses domes, the Mediterranean Hellenization hardly reached a few kilometres from the coast and in the interior of the countries, where the only fruit to be harvested from the ground consisted of stones, the shepherds and the farmers of those dry places kept the tradition. The Levantine Maestrazgo has examples and craftsmen who still follow that system. Ref. 14 shows a wide analysis of its different types and its usefulness (Fig. 1.26). Fig 1.27 shows some examples, that have extremely disordered bonds (Fig. 1.28). In Apulia, beside the Adriatic sea, in the town of Alberobello the so-called Trulli (Fig. 1.29) are still built and have become one of the main tourist attractions of the place. According to legend, the principal reason for this way of building was the necessity to evade the tax on houses. When the collector appeared in the town he only found rubble piles for which, evidently, he could not demand payment. No sooner did he disappear than the stones were return to their original place since these vaults could practically be taken apart, so that a construction of a four metres span could be rebuilt in two or three days at the most by a pair of workers. Apart from this suggested explanation, we are again talking about pointed profiles stable enough to resist an earth tremor: in any case, easy to rebuild. Ref. 31 deals in more detail with this interesting type of very flat limestone stones whose schematic evolution can be seen in Fig. 1.31. Now we are going to spend more time in every geographic spot where these limestone eggs have grown. But we cannot forget that the British Isles, paradoxically involved in the commerce of tin since early times, have clear examples that share the territory with the great megalithic monuments of Stonehenge and Avebury in England, Yvias in France (Fig. 1.32), and New Grange, Dowth and Knouth, in Ireland, between 2500 and 1700 BC. The medieval Irish monks had built vaults with protruding stone profiles since the 7th century as, for instance, in the Gallarus oratory, in Dingle (Fig. 1.33). In the centre of France constructions exist very similar to the Trulli, called Bories, that can be added to the long list previously mentioned. In Salat can be found the very well made Breuil cabins (Fig. 1.34) that

Fig. 1.36a and b. House in La Mancha in Spain. Outer and inner view (Jarque).

Fig. 1.37a and b. Terraced houses in Menorca in Spain. Outher and inner view (Jarque).

in some cases have a kind of mezzanine and windows of a certain complexity. The attempts to reproduce the technique today have not been too satisfactory (Fig. 1.35). Better constructions can be found nowadays, such as those in La Mancha (Spain), with more regular courses and using mud as a settling element, which

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The Great Structures in Architecture

Fig. 1.38. Beehive house in Syria. Plan of the whole building.

Fig. 1.41. Etruscan tomb in Montagnola. General view, section and plan.

gives them more stiffness (Fig. 1.35). In Minorca, ziggurat-like terraced constructions of great beauty are presently used (Fig. 1.36), whereas in Provence constructions of a large size and perfect carving are still being built (Fig. 1.37).

Fig. 1.39. Beehive house in Syria. Section of a dome.

Fig. 1.40. Etruscan tomb in Casale Maritimo. Inner view of the disposition and the symbolic central support (Ortega).

16

In the Middle East too, though almost solely in Syria, the so-called Beehive Houses that are based on the same principles but made of bricks are still built [Ref. 20 ]. They gather in similar units of repetitive shape, forming houses with interior courtyards packed with various rooms (Fig. 1.38). Each dome rests on a square base (sometimes round) of brick or stone whose inner dimensions go up to 5 x 5 m. The 80 cm thick walls support the staggered brick dome that rises up to an inner height of 3.5 to 4.5 m (Fig. 1.39). When the piece is rectangular it is divided by means of a central arch that allows the support of a pair of domes. A great construction uses four to five thousand bricks of 25 x 46 x 7 cm and a team of workers spends about 10 to 15 days in its building. With this list of places it is not the intention to exhaust the subject, which is impossible anyway, since there is little published about it, due to researchers’ lack of interest. A last question before ending: why the powerful ensuing civilisations went for less efficient systems? The Egyptians, great stone builders, used advanced courses arches that ran along covering narrow corridors. The Babylonian empires went for mud, which they had in abundance, the Greeks had more aesthetic than technical sensitivity and the Romans discovered the voussoirs dome, considering it a pattern suitable enough to tirelessly repeat it.

Stones Resting on Empty Space

Fig. 1.42. Etruscan tumuli in Cervetery.

Fig. 1.43. General view of the temple of Bruvanesvar (Schlaich).

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The Great Structures in Architecture

imposing inner support of symbolic character since it did not have any influence on the structure. Other later important cultures, such as the South Asians in their pagodas and stupas and the Aztec in their temples, put into practice part of the principles of the protruding stones. Indian constructions are also built according to the advanced courses vaulting principle, achieving such spectacular results that it is not easy to choose a single example. Fig. 1.43 shows an impressive picture of the temple of Bhruvanesvar, whereas in Fig. 1.44 its elevation and sections can be seen. Fig. 1.45 shows a 19th century picture of the town of Varanasi. The thorough examination of the resistence principles of temples and stupas goes beyond the goals set by the author, however tempting that task could be. Crocci (Ref. 10), mainly because of his work as a restorer, is the author who has most studied these types of monuments from the structural viewpoint, finding that most of the problems arise from floor shifting, which causes wall leaning (Fig. 1.46). Besides, this fact leads to an increase of the shear stresses in the horizontal contact surface between the blocks (Fig. 1.47).

Fig. 1.44. Elevation and sections of the temple of Bruvanesvar (Stierlin).

Fig. 1.46. Effects of the outward rotation of the base in a corbelled arch (Croci).

Fig. 1.45. Picture of 19th Century of the city of Varanasi.

Only their predecessors, the Etruscans, made an attempt to connect with tradition, in some tombs like the Tholos of Casale Maritimo (Fig. 1.40), the Montagnola tomb (Fig. 1.41) from 600 BC, or the burial mounds of Cervetery (Fig. 1.42), all of them with an

18

Fig. 1.47. Variation of the shear forces in a corbelled arch due to rotation of the base (Croci).

Stones Resting on Empty Space

This last consequence forces Crocci to use strong metallic elements (Fig. 1.48), since he considers the structure working as Fig. 1.49 shows in a simplified way. Nevertheless, even though the Fig. 1. 50 reinforcement seems suitable, it is a contradiction in structural terms that affects the system concept. The more precise analysis of a tholos in Sardinia (Ref. 25), carried out by Roberti and Spina using the Finite Element Method, considers the following elements:

Fig. 1.51. A bird´s eye view of the Nuraghe Santu Antine (Roberti and Spina).

Fig. 1.48. Possible layout of transversal chains and tie-bars to strengthen a tower (Croci).

Fig. 1.52. Velocity vectors and contact closures at collapse for the dome built without backfill.

Fig. 1.49. Stresses in a corbelled dry block tower (Croci).

(i) independent blocks, (ii) deformable contacts and (iii) an explicit time-domain solution of the original equations of motion. In the tholos considered, the Nuraghe Santu Antine in Sardinia (Fig. 1.51), it has been used as a method that considers the fabric stability as a rigid solid.

Fig. 1.50. Possible function of the iron beams in the Sury temple (Croci).

If we took a nostalgic glance at so many techniques that were lost by ignorance or intellectual imposition we would find in the advanced courses domes a nonrecoverable example. Today it would not make any sense using materially economic but labour intensive systems. Maybe other cultures thought something alike. But knowledge is a great pleasure that may have in those cupolas an exotic ingredient unknown by most people.

19

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REFERENCES OF CHAPTER 1

1. BLANCO FREIJEIRO, A. “Arte Antiguo del Asia Anterior”. Sevilla, Universidad, 1975. 2. BLANCO FREIJEIRO, A. “Arte Griego”. Madrid, C.S.I.C., 1984. 3. BOËTHIUS, A. “Etruscan and Early Roman Ar chitecture”. Yale University Press, USA, 1994. 4. CARRIAZO, J. de la M. “Arquitecture Prehistórica”. Cartillas de Arquitectura Española, Madrid, 1929. 5. CHASSAGNOUX, A. “Persian vaulted Architecture: Morphology and equilibrium of vaults under static and dynamic loads”. Structural Studies of Historical Buildings IV. Computational Mechanics Pub, Southampton, 1995. 6. COLL, G., GONZÁLEZ, R., HOLTZMAN, B. “El gran arte de la Arquitectura. Roma”. 7. CONANT, K.J. “Arquitectura Carolingia y Románica. 800-1200”. Manuales Arte Cátedra, Madrid, 1982. 8. CORZO SANCHEZ, R. “La antigüedad. Historia del Arte en Andalucía”. T. I. Sevilla, Gever, 1989. 9. CHILDE, G. “Los orígenes de la civilización”. México, Fondo de Cultura Económica, 1954. 10.CROCI,G.”The conservation and structural Restoration of Architectural Heritage”. WIT Press, 1998. 11.DANIEL, G. “Conjuntos megalíticos”, en Investigación y Ciencia, 48 (Septiembre, 1980), pp. 42-52. 12.ESCRIG, F. “Domes and Towers in Architecture”. Computational Mechanics Pub, Southampton, 1998. 13.FLETCHER’S, B. “A history of Architecture”. Butterworths. 19 ed., London, 1987. 14.GARCIA LISON, M., ZARAGOZA CATALAN, A. “Arquitectura Rural primitiva en Sec”. Temes d’Etnografía Valenciana. Institut Alfons el Magnanim, 1982. 15.GIMENEZ REINA, S. “Los Dólmenes de Antequera”. Biblioteca Antequera. Caja de Ahorros de Antequera, 1974. 16.GUIDONI, E. “Arquitectura primitiva”. Madrid, Aguilar, 1980. 17.HEINLE, E. & LEONHART, F. “ Tours du monde entiere” Livre Total, 1989.

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18.JARQUE, F. “L´habitatge temporal. L´ome i la pedra 2.” Universidad de Valencia, 2004. 19.MATA CARRIAZO, J. “Arquitectura Prehistórica”. Cartillas de Arquitectura Española I, Madrid, 1929. 20.LLOYD, S. & MULLER, H.W. “Arquitectura de los orígenes”. Madrid, Aguilar, 1980. 21.ORTEGA ANDRADE, F. “Historias de la Construcción. Mesopotamia, Egipto, Grecia y Etruria. Libro Primero”. Publicaciones de la Universidad de Las Palmas, 1993. 22.PIJOAN, J. “Historia del Arte”. Tomo I. Ed. Salvat, 1974. 23.RENFREW, C. “Arqueología social de los monumentos megalíticos”, Investigación y Ciencia, 88 (Enero, 1984), pp. 70-79. 24.RIBA, D. & MOULIN, J. “El enigma de los primeros constructores”. Barcelona, Libroexpres, 1981. 25.ROBERTI, M.G. & SPINA,O. “Discrete element analysis on the Sardinian Nuraghe” Historical Constructions 2001.Guimaraes.Universidad of Minho. Portugal, 2001, pp.719-727. 26.SYRMAKEZIS, C. “Domes in Creta”. Museo Cretense de Etnología, 1988 (in Greek). 27.SOUZA GOIS, M.I. “Cúpulas de Tierra”. Master Thesis ETSA de Sevilla. Prof. Escrig, 1995. Not published. 28.STIERLIN, H. “Encyclopedia of World Architecture”. Taschen, 1977. 29.TRACHTENBERG, M. & HYMAN, I. “Arquitectura. De la Prehistoria a la Modernidad”. Akal, Arte y Ciencia, 1990. 30.VELAZQUEZ BOSCO, R. “Cámaras sepulcrales descubiertas en término de Antequera”. Revista de Archivos, Bibliotecas y Museos, n1 9. 1905. 31.VERNICE, B. “Los Trulli”. Primer Congreso de Historia de la Construcción, Madrid, 1996, pp. 515-523.

The Invention of the Dome

Chapter 2. THE INVENTION OF THE DOME

Without doubt, the invention of the arch, according to the remains found in excavations, must be attributed to any of the civilisations that developed in the Middle East. There the earth has no end and dust and mud are the only materials that separate men from floods and that can lift them up closer to the sky. Mud and bushes are the only available materials to make the trousseau or the former means of writing and to build houses, palaces and fortifications. The arch became the only feasible form for covering the empty space between two walls with a soft material, and it was profusely used as an alternative to palm tree trunk beams or plaited reed beams. Physically constructed arches can be found in Khorsabad, in the Palace of Sargon (722 BC) or in Niniva (Fig. 2.1). From the arch to the vault there is only the requirement of a bigger framework, which could not be an obstacle in great works, such as that of a palace, but certainly was a problem in more popular ones, as in expensive civil works. That is why, in addition to the building techniques, of the vaults other examples can be found not requiring provisional

Fig. 2.1a. Ishstar gate of the Palace of Niniva in Babylon. Previous state.

support. For instance, in Fig. 2.2 can be seen a small brick covering at Tell al Rimah (2100 BC), in which one brick supports the following one with the aim of saving the construction of shoring. The same system, though better organised, was used in the Khosabad sewers (Fig. 2.3). But vaults are linear elements, in a certain way a prolongation of arches, which were known by all the civilisations. Curiously enough, whereas in false vaults and arches a pointed shape is required, in true vaults and arches the semicircular shape is chosen from the beginning, which shows that the passage from the former to the latter is obligatory in the search of more harmonious geometries. The Greeks in Olympia (Fig. 2.4) and the Etruscans in Volterra (Fig. 2.5) showed a skill in accurate stone carving that, if not surprising, is solid proof of a building maturity. In contrast, none of them shows clear proof of the use of domes, that is to say the revolutionary new form.

Fig. 2.1b. Ishtar gate of the Palace of Niniva in Babylon. Reconstruction.

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Fig. 2.1b. Ishtar gate of the Palace of Niniva in Babylon. reconstructive system.

Fig. 2.5 Etruscan door in Volterra. Fig. 2.2. Brick dome in Tell al Rimah.

Fig. 2.3. Drain under Palace Plattform in Khorsabad.

Fig. 2.6. Relief from Ninive, wherein a domed village can be seen (Schlaich).

Fig. 2.4 Access to a theatre in Olympia.

22

Fletcher (Ref. 6) shows in his book a relief reproduction found in Niniva, dating from 700 BC, suggesting that some houses could have been covered with small domes (Fig. 2.6); Schlaich (Ref. 20) shows a picture of this relief, but no excavation results lead us to that conclusion, among other things because the tight mesh of irregular reticules that formed towns did not go well with central covers and, either in Egypt as in Babylon,

The Invention of the Dome

Fig. 2.7. Earth block domes village near Alepo in Syria (Minke).

Fig. 2.9. Stabianas Thermae in Pompeii (García Bellido).

Fig. 2.8. Earth block domes in Siestan, Afghanistan (Minke).

to get protection against floods it was necessary to compact the neighbourhoods and to close the streets with doors or lift them up on platforms. Otherwise, the dome has a problem in comparison with the vault: the wearing of a piece leads to the total collapse, which does not happen in the case of longitudinal forms. Therefore, it is difficult to deduct whether vaults have an Eastern origin or not. Anyway, there is no doubt that the first dated vaults belong to the Roman Republic. We find them as parts of thermal buildings, following very normalised models. That is the case of domed Frigidarium, vaulted Tepidarium and mixed up Caldarium.

Fig. 2.10. Forum Thermae in Pompeii (García Bellido).

Present images of Middle Eastern villages are deceptive, since they may look as of ancient vernacular architecture, very similar to that seen in Fig. 2.6. Figs. 2.7 and 2.8 show primitive looking images, all of them subsequent to the 4th century AD, when Romans had already exported those geometries. Dating from the second century BC we can mention the Stabianas thermae (Fig. 2.9) or the Forum ones (Fig. 2.10), both in Pompeii, which dating does not give rise to any doubt since it was not possible to make later reforms. In Pompeii there was another group of thermal baths, the Central one, of which we do not know the layout. The model of thermal vaults must have been set long before and it practically consists of a hemisphere sitting on a cylindrical drum having the same height and radius. The ventilation and the illumination take place through the oculo of the headstone and the implantation on an orthogonal reticule is done by means of niches in the corners (Fig. 2.11).

Fig. 2.11. Sketch of the initial planning of the Roman domes (Escrig).

These vaults have a very stable structural behaviour because they are firmly supported by heavy walls and their thickness diminishes as it gradually approaches the headstone, which receives all the weight. Although this constructive system is not the optimum, because of the need of a complete formwork, it has evident advantages. In the first place it is monolithic, since it is based on a pozzolana concrete, resistant and light. In addition, it is compatible with the introduction of brick strips. In principle there are no limitations for the space to cover. The inferior hemispheric form and the

23

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PANTHEON DOME Complete dome Dome with oculo

Fig. 2.12. Funicular working of the semicircular domes, with and without oculo.

Fig. 2.13. Shrine of Hoessn Soleiman in Syria (García Bellido).

outer cap allow the inclusion of a parabola of pressures that makes it work specially well. Fig. 2.12 shows a drawing of the loads funicular within the section where it can be seen that this line does not exceed the third of the section, that being the reason why it does not cause flexions.

on the intersection of four cylinders on an orthogonal plan, following a model that, otherwise, is identical to the hemispheric one, but for the niches in the corners (Fig. 2.14b).

When talking about the Pompeii thermae we must also mention that the caldarium had a mixed form, that is to say, a cylindrical vault ending in a quarter of a sphere that in the case of the Forum thermae even had a lateral perforation. Here the vault concept has disappeared, being replaced by a form very usual at the back of Forums and Temples, whose stability is based on a powerful frontal diaphragm plate (Fig. 2.13). This demonstrates that whether or not its inventors, the Romans, were first in dicovering the characteristics of the system, that they used and could afford to transform it at will. But the discovery and use of the vault are but the first step in benefiting from its great potential, not to mention the numerous examples that confirm small advances. Let us have a look at the Domus Aurea vault (70 AD) of 13 m diameter (Fig. 2.14a). The first problem that must be solved is how to fit it in a perfectly orthogonal mesh without wasting space. The solution consists

24

The modernity of the plan is characteristic of some of our contemporary architects (Fig. 2.15). Thickness has been reduced to the minimum thanks to the counteracting barrel vaults. In fact, the system of illumination through the ceiling of the contiguous pieces is impressive and its inner aspect, so regular and with no marble or decoration, shows a geometric purity only common in maturity. The flat arches, the horizontal courses that advance towards the empty space and a penetration through the big hollows that occupy 75% of the walls surface look as if the globes are floating in the air rather than a vault (Fig. 2.16). In contrast, the Domus Augusta (92 AD) constructed also with an octagonal plan in the days of Domitian and measuring 10 m in diameter, is of a smaller and in a certain way more primitive complexity, although its building does not force the rooms to spin diagonally and, therefore, leaves less residual space. But an important contribution that still has not appeared in the previous examples consists of the arches discharging on lintels and on the surfaces where weight is wanted to be transferred to the buttresses (Figs. 2.17 and 2.18).

The Invention of the Dome

Fig. 2.14b. Plan of the Domus Aurea (Ward Perkins).

Fig. 2.14a. Scheme of the dome of the Domus Aurea (Escrig).

Fig. 2.15 Section of the Domus Aurea, showing its ceiling illumination system (Ward Perkins).

Fig. 2.16. Inner view of the Domus Aurea.

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Between 115 and 130 AD, Adriano, an emperor of oriental mentality whose arguments with Trajano’s, his mentor architect, are well known because this Apolodoro was a rationalist of its time, built the Pantheon, or rather rebuilt it on a previous building made by Agrippa. The Pantheon is a way to take to the limit the thermal vault in its simpler but at the same time more sophisticated state (Fig. 2.19).

Fig. 2.17. Perspective of the Domus Augusta (Ward Perkins).

It is simple because it is supported by a perfectly circular drum with a cap able to keep within a complete sphere and responds to the first model found in Pompeii. It is sophisticated because it is able to set up directionality by means of a hierarchy of hollows and cornices of complexity. The system of curved lintels and three-dimensional arches not only did not have any precedent but, in addition, that the constructive system used to cover a 43.3 m inner diameter and a similar height reveals an inventiveness that has never been used again. The vault is really made up of a spatial lattice that is camouflaged as a reticular coffered ceiling. Besides, walls and caps transmit the action by means of discharging arches superimposed (Fig. 2.20), everything being finally gathered with a concrete layer (Ref. 16). So much has been written on this building that it is a redundancy to expand on the matter. In our opinion it is a point of inflection, according to our arguments, in the Roman constructive technique in several senses:

Fig. 2.18. Section and plan of the Domus Augusta (Ward Perkins).

a) It demonstrates that the vault has a potential to cover wide spaces that do not have other types of vaults. b) It creates an eastward tendency to the detriment of the Greek one. c) Concern for the constructive procedure predominates over the formal one, which at last is a result of the former. d) It gives way to new architectonic types. e) It turns height and ceiling illumination into a new spatial value. Apart from that, each one of the vaults constructed in the days of Adriano meant a step ahead with respect to the previous ones. In the Leptis Magna (Libia) thermal building several substantial new features are introduced of which an architectonic ornament made up of sixteen layers, eight of them cylindrical and the other eight gathering the lunettes of the windows, so that when joining before arriving at the key, become a continuous spherical cap, is not the least important. This permits construction of the optimal formwork (Fig. 2.21 and 2.22). The same can be said of Baiae (Fig. 2.22).

Fig. 2.19. Scheme of the Pantheon of Agrippa (García Bellido).

26

The other innovation consists of a line of windows positioned between the drum and the dome that illuminates the interior instead of a central oculo and high enough as to overlook the contiguous rooms.

The Invention of the Dome

2

1

3

Plan and first stage

Section

LAYER 11 INTERIOR Interior layer and coffersAND COFFERS LAYER OF MERIDIANS 22 INTERMEDIATE Intermediate layer of meridians and parallels 3 AND Exterior layer made of concrete and relieving arches PARALLELS 43 EXTERIOR One of the eight supports LAYER MADE OF CONCRETE 5 Brick arches AND RELIEVING ARCHES 4 ONE OF THE EIGHT SUPPORTS 5 BRICK ARCHES

5

4

Level of the great cornice

6 Construction of the dome 10 5

9

11 7 6 7 8 9 10 11

Three tiers of relieving arches Meridian ribs made of brick Parallel ribs also in brick Relieving arches Continuous layer of puzolanic concrete Buttresses of the dome 7

8

8

Fig. 2.20. Scheme of the construction phases of the Pantheon of Agrippa (Ortega).

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Fig. 2.22. Scheme of the dome of Baiae (García Bellido).

Fig. 2.21. Group of thermal buildings in Leptis Magna in Libya (García Bellido).

Fig. 2.23 shows a plan of the Horti Sallustiani in Rome, where the directionality of the 26.3 m in diameter space has been achieved by enlarging disproportionately the entrance hollow and by prolonging that of exit, resulting in the Palladian basilicas that we will see below. In Adriano’s villa, the emperor gave absolute free rein to its fantasy and intuition, finding there an enormous variety of forms and solutions that seem impossible to remain standing (Fig. 2.24). The most surprising are those surrounding Piazza d’Oro.

28

Fig. 2.23. Nimphaeum of the Horti Salustiani, in Rome (García Bellido).

The Invention of the Dome

Fig. 2.25b. State of the hall at the end of the XIXth Century.

Fig. 2.24. Piazza d’Oro in the Villa Adriana, in Tivoly.

Fig. 2.26a Plan of the main building of the Villa Adriana, in Tivoly.

Fig. 2.25a. Drawing of the hall of Piazza d’Oro in the Villa Adriana, in Tivoly.

Fig. 2.26b. Perspective of the main building of the Villa Adriana, in Tivoly.

The lobed dome over its hall simplifies that of Baiae, although it maintains the illumination through the key

and loses directionality. But the fact of its remaining standing in spite of being supported by eight lunettes is a clear sign of its structural effectiveness (Fig. 2.25).

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Fig. 2.27a. Bathrooms in the Villa Adriana, in Tivoly. Sections.

Fig. 2.27c. Bathrooms in the Villa Adriana, in Tivoly in the actuality.

Fig. 2.27b. Bathrooms in the Villa Adriana, in Tivoly. Plan (García Bellido).

In the great baths of Tivoli the sequence of hemi capgroined vault-dome, makes up a real form exhibition. There, it is appreciated as the ordered way to connect the elements of the whole and the independence to perforate the walls with great colonnades rather than as individual achievements. But it is in the main building of Piazza d’Oro where form has not been surpassed until the present time (Fig. 2.26). Here we find a dome that no longer is used to cover a circular, not even polygonal, plan. There we have a winding form that nobody would think capable of being covered because of the complexity of its space and the limited dimension of its buttresses and columns of complete permeability. Although nowadays a 13 m diameter is not too much, building a dome on

30

columns balanced by attached dome sectors, as those later made in Byzantium, was in its moment an innovation difficult even to think of. And it was still more difficult in the arrangement of the 20 m side square on which was implanted a cramming of vaults and domes where even a toric dome could play a main role. If we compared it with the Domus Aurea dome, we could realise the enormous strides made by building techniques in a very short time. Only a century and a half from the Treasure of Atreo to the Neronian construction, and hardly a half more, to arrive at this filigree supported by slender columns. Piazza d’Oro prefigures constructions of wood or steel, but nobody would dare to make it of stone or brick, not even the gothic constructors who knew the static

The Invention of the Dome

laws and achieved height under the penalty of thick bundles of columns. The baths must be considered as a masterpiece also (Fig. 2.27). What else can be done after the Tivoli Villa? Lightening the walls with deep lobes as in the Pergamon Asklepieion by Antonino, with a 26.5 m diameter (Fig. 2.28). Inventing the true drum as in the temple of Medical Minerva? (Fig. 2.29)? Little more, indeed. But if we analysed the constructive systems, any of these works would contribute excellent new features. The 250 AD temple of Minerva, with a 24 m diameter and a height of 33 m, is very well tied with bands of bricks in several threads (Fig. 2.29); the Diocletian Mausoleum in Spalato has an interesting construction made exclusively of bricks placed as fish scales (Fig. 2.30). The Treveris thermae have a hugely perforated drum, thanks to the perfect relief given by the brick arches (Fig. 2.31).

Fig. 2.29b. State of the Temple of Medical Minerva at the end of the XVIIIth Century.

Fig. 2.29c. Present state of the Temple of Medical Minerva.

Fig. 2.28. Plan of the Askleipeion of Pergamo (García Bellido).

Fig. 2.29a. Outline of the Temple of Medical Minerva (García Bellido).

Fig. 2.29d. Constructive scheme of the Temple of Medical Minerva (Drum).

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Fig. 2.30a Scheme of the dome disposition of the Diocletian Mausoleum, in Spalato.

Fig. 2.30b. Inner view of the Mausoleum dome (Hébrand).

From that moment, the changes are the consequence of an alteration in the type of plan. This is due to the needs of the new Christian cult. The Saint Constanza Mausoleum has only a 12 m diameter and a height of 20 m, but it is surrounded by a permeable gallery through a colonnade that duplicates the useful diameter (Fig. 2.33). This, together with the existence of a drum as the one in Treveris Thermae and even a columned peristyle, inaugurates a model of central plan only altered by a crossed access narthex repeated over and over again (340 AD), as the tomb of the Calventii of hexagonal plan (Fig. 2.34) or Saint Gideon in Colony, of oval plan (Fig. 2.35).

32

Fig. 2.31. Plan of the Treveris Thermae (a) and present state (b) (García Bellido).

The Invention of the Dome

Fig. 2.34a. Plan of Saint Gideon, in Colony (Krautheimer).

Fig. 2.32 Mausoleum of Saint Constance (García Bellido).

Fig. 2.34b. Primitive state of Saint Gideon, in Colony (Escrig).

Fig. 2.33 Mausoleum of the Calventii (Renaissance Drawing).

Fig. 2.34c. Medieval state of Saint Gideon, in Colony.

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as in Saint Lorenzo in Milan, now unrecognisable because of its baroque restoration, that formerly must have been covered with a groined vault (Fig. 2.35), balanced by attached domes. The innovation here lies in the fact that the circumvallation gallery has two floors. As is well known, Adriano’s empire was the largest one under a single administration during the whole Roman period and though the western provinces adapted very well to the official architectonic patterns, the eastern ones defined their own types with a vigour.

Fig. 2.35a. Plant of Saint Lorenzo in Milan (Krautheimer).

Fig. 2.36. Perspective of the Basilica of the Saints Peter and Marceline and Mausoleum of Saint Elena, in Rome (Krautheimer).

Fig. 2.35b. Original pattern of Saint Lorenzo in Milan (Escrig).

Fig. 2.37a. Perspective of the Basilica of Saint Peter and Saint Andrew (Krautheimer).

Fig. 2.35c. Actual state of Saint Lorenzo in Milan (Krautheimer).

Those two examples inspired the Renaissance architects; mainly the former, that helped Borromini to settle his Ivo della Sapienza scheme, practically with the same size. Other complications appeared when a square enclosure without octagonal transit was to be covered,

34

Fig. 2.37b. Plan of the Basilica of Saint Peter and Saint Andrew (Krautheimer).

The Invention of the Dome

A very special example, mainly because of its symbolical meaning rather than its structural content, is the 33.7 m diameter Anastasis Rotunda in Jerusalem, whose shape we know thanks to the 1609 engraving by Callot, copied then from the original construction still standing. This example would inspire the construction of the Dome of the Rock, seen below, with its nerved wood cover (Fig. 2.38) that introduced great variations, although could not hide their basilica or central temple origins.

Fig. 2.39. Saint Minas, in Abu Mira, and Baptistry (Krautheimer).

First, the predominance of stone instead of brick and the Roman cement. Second, the complex geometries full of colonnades that mix straight and curved lines, transepted basilicas, apsidal endings or diagonally spun spaces. Precedents can be found in some constructions in Rome as Saint Peter and Marceline Basilica with its ending transept and crowned by the Saint Elena Mausoleum (Fig. 2.36) with a 20 m diameter. Or as Saint Peter Basilica, combined with the Honorio Mausoleum and the Saint Andrew Rotunda (Fig. 2.37). .

Fig. 2.40. Saint Philippe Martiryum (Krautheimer).

Fig. 2.38a. Anastasis Rotonda in Jerusalem in 1609 (Callot). Fig. 2.41. Qual’at Siman (Krautheimer).

Fig. 2.38b. Anastasis Rotonda in Jerusalem by de Bruyn in the seventeenth century.

Fig. 2.42. Saint Babilas, in Antioquia (Krautheimer).

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But no construction involves as much complication as Saint Minas, in Abu Mira at 412, and its Baptistry (Fig. 2.39), Saint Philippe Martyrium (about 400 AD) (Fig. 2.40), the 1480 Qual’at Siman (Fig. 2.41), Saint Babilas’ in Antioquia (Fig. 2.42), dating from 379 AD, or the innumerable examples that repeat some of the models from the metropolis:

Sergio Martiryum in Resaffa (Fig. 2.48) and some churches like those shown in Fig. 2.49. Also, the incipient Greek cross plans shown in Fig. 2.50, that due to its dating make it possible to know whether they exerted some influence over the Persian architecture or else were influenced by it, the latter being more likely.

The Tomb of Virgin Mary in Jerusalem, dating from 450 AD (Fig. 2.43) and the Church of Theolokos, dating from 484, both coming from Saint Constance as well as the Selencia-Pieria Martiryum (Fig. 2.44), the Cathedral of Bosra (Fig. 2.45) or the Resaffa Martiryum (Fig. 2.46), all of them coming from Saint Lorenzo’s in Milan. Though the mentioned examples recall former ones, there are other types of an unquestionable newness. The parabolic dome of the Saint Joseph Martiryum in Zorah (Fig. 2.47), the vaulted basilical plan of the Saint

Fig. 2.45. Cathedral of Bosra (Baldwin Smith).

Fig. 2.43. Tomb of the Virgin Mary in Jerusalem (Baldwin Smith).

Fig. 2.44. Martiryum of Selencia Pieria (Baldwin Smith).

36

Fig. 2.46. Martiryum of Resaffa (Baldwin Smith).

The Invention of the Dome

Fig. 2.49a. Church of Bizzos, in Ruweha (Baldwin Smith).

Fig. 2.49b. Church of Il-Anderin (Baldwin Smith). Fig. 2.47. Martiryum of Saint George, in Zorah (Baldwin Smith).

to be seen in the following chapter. In that movement the centralised plan schemes, of which Romans were so fond, were used with absolute mastery, as well as those of the one or more naves basilical plan, to be inherited by the Christian tradition during the Romanesque style, clearly inspired in these eastern examples and brought to the West by the pilgrims to Holy Land. Also, the schemes of cruciform plan, an innovation not to be considered in the West until the Gothic style; and finally, the rotunda schemes, the greatest exponent of which was the Palatine Chapel in Aquisgran. All this architecture from the Eastern plateaus would have an important future influence, since even Justinian used it as a precedent for his great revolution.

Fig. 2.48. Martiryum of Saint Sergio, in Resaffa (Baldwin Smith).

All these constructions could be made thanks to the initiative and support of the Byzantine emperors, to the point that it is not possible to think that eastern architecture begins in the 6th century, however true the fact that then starts a completely new movement,

We must consider that the eastern dome, which was not developed until the 3rd century, returned from Rome totally transformed and full of new possibilities that the Persian and Sassanid constructors developed with a clear autonomy and that later would exert influence over the Roman works in the bordering territories. We owe these eastern constructors great inventions that the Romans pursued but were not able to shape: the pendentives, the trumpet shells and the control of the square plan. In contrast, the Roman experience was able to propose more rational global arrangements and the hierarchisation of the different architectonic elements. It seems that in the 1st century BC the Parthians were able to construct some domes of parabolic form on trumpet shells but there is nothing left, except for much more subsequent examples that must have been influenced by the portentous Roman technique.

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The Great Structures in Architecture

Fig. 2.50a.

Fig. 2.50b.

Fig. 2.50c.

Fig. 2.50e. Fig. 2.50d.

Fig. 50f.

Fig. 50g.

Fig. 50h.

Fig. 2.50a. Martiryum of Saint Elias. Plan. Fig. 2.50b. Elevation of the Martiryum of Saint Elias. Fig. 2.50c. Present aspect of the Martiryum of Saint Elias. Fig. 2.50d. Plan of the Martiryum of Chagra. All Figures belong to E. Baldwin Smith (Ref. 21)

Fig. Fig. Fig. Fig.

In spite of this debt to western culture, we cannot but admire the magnitude of their palaces and the skill of their constructive solutions. The Sassanid Persians gave place to certain types that would never be forgotten. On the one hand, the palaces reticular arrangement with the access through a vaulted ivan of great magnitudes that reached 25 m span and 30 m

height and on the other hand, the way centralised spaces were crowned with a great variety of vaulted forms that looked from the outside like mountains in the centre of the whole. The ivan was an access that would soon be adopted by Persian, and later Hindu, architecture, but was an inversion of the domes in half a cappet of sphere that covered the Roman temples.

38

2.50e. Outer aspect of the Martiryum of Chagra. 2.50f. Plan of the Tomb of Bizzos, in Ruweha. 2.50g. Section of the Tomb of Bizzos, in Ruweha. 2.50h. Outer aspect of the Tomb of Bizzos, in Ruweha.

The Invention of the Dome

Fig. 2.51. Plan of the Palace of Firuz Abad (Upham Pope).

Fig. 2.52. Structural scheme of the Palace of Firuz Abad (Ortega).

Fig. 2.53. Plan of the Palace of Bijapur (Upham Pope).

Fig. 2.54. Building section of the Palace of Bijapur (Upham Pope).

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The centralised dome on a square or cruciform plan was an optimal way to integrate in complex enclosures the circular plan that the Romans constructed without covering by its nature. Thus, the greater works constructed by the Sassanians, as for example Firuz Abbat Palace, by Ardashir I (Fig. 2.51), was made up of a dozen vaulted spaces and three domes with an 11 m diameter, probably with a cambered shape. All of it perfectly ordered in a rectangular enclosure of 104 x 55 m2 that includes a great ivan and a courtyard, dating approximately from 250 AD. Ortega (Ref. 17) has studied in depth this sassanid construction and makes an assumption of the palace that we support because, though the domes are of small dimensions they are cambered, made of a single shell of variable section and must have surely been disposed in such a way that they do not need craddlings nor shoring. The walls that support them have a tremendous thickness around 5 m, which must be justified by other reasons apart from the structural counteracting. Fig. 2.52 shows what must have been its geometric outline as well as a possible disposition. There is no doubt that none of these sassanid constructions could have been built without the previous contact with the Roman culture, no matter how much their appearance is fully Eastern like. We have already spoken of the step forward represented by the domes on square plan; nevertheless they are of an inconceivable primitivism as for the reception of light and the ventilation of the enclosures, though not because the builders did not have the solution at hand. But this solution would not appear until the Byzantine Empire fused the Mediterranean tradition and the Eastern one.

Fig. 2.55. Passage from the octagonal plan to the circular one in the Thermae of Caracal (Robertson).

40

Fig. 2.56. Plan of the Palace of Sarvistan (Upham Pope).

Fig. 2.57. Dome of the Palace of Sarvistan and isostatical lines of the dome intrados (Chassagnoux).

Fig. 2.58. Resting point of the tonal arches (Upham Pope).

The Invention of the Dome

The other fully Eastern contribution is the accumulation of domes, meaning the loss of the main role played by the single space. The Eastern architecture resorted very frequently to the multiplication of domed spaces in a repetition deprived of hierarchy, although in many cases one of the forms stood out among the others. It was like that to such extent that Bijapur Palace, constructed by the second member of the dynasty, Shapur I, consisted of only a great dome. But also in this case it was built on a cruciform shape of square base. The passage from this complex plan (Fig. 2.53) to the circular one requiring a dome of parabolic directrix, was done for the first time by means of the intersection of cylinders (Fig. 2.54). A 24 m diameter placed it close to the most spectacular Roman constructions. Since there is nothing left of the vault, its construction and its real form are but a supposition. But it is possible to draw very accurate conclusions from the surviving ones. Without a doubt the builders did not know the pendentives necessary to arrange the joining of the cylinders intersection, but they used a kind of course approaching that already put in practice by the Romans in the thermae of Caracal (Fig. 2.55) that surely the Sassanians learnt from the Roman prisoners who worked on their constructions. A century later, Sarvistan Palace shared the same exposed characteristics and timidly started locating the illumination windows at the height of the drum (Fig. 2.56), which caused force concentrations that had not existed to date. Chassagnoux [Ref. 1] made an analysis by finite elements in which there could be found a concentration of isostatical forces in the key of the openings that reached a 1.5 kp/cm2 traction (Fig. 2.57). They created too some original forms like the vaulted room of Fig. 2.58, with columns giving complexity to the space. The Sassanid Empire stereotyped these forms and from that moment on repeated them in a

mechanical way without even paying attention to the great advances made by the Byzantine constructors. Remarkably, despite the fact of being aware of the technology around them, they never used any other Roman solution like the groined vault, the circular cylindrical one or the spherical dome. The great success of the half-sphere dome, with or without oculo and on drum or without it, was due to its optimal structural behaviour. Recent studies trying to interpret its few detected pathologies revealed that its easy construction is combined with a great geometrical rigidity. The Roman domes were built mainly of pozzolanic cement, of brick or of a mixing of both. This gave them a monolithic aspect that would escape those made of stone in the Renaissance and in behaviour closer to that of present day concrete domes. That is why some mathematical attempts were relatively right. The Pantheon dome has been studied profusely. Thus Mark [Refs. 12 and 13] sets out an analysis considering a cylinder of 5.5 m thickness with the section of Fig. 2.59 and obtains maximum efforts of 2.8 kg/cm2. It is surprising that when the reinforcements are eliminated, the efforts decrease by 20%, but they have a stabilising effect that increases the compressions and diminishes the cracking. Theoretically, cracking must reach a height of 54º from the top and the reality verified in the work is very similar, according to the drawings by Terenzio (Fig. 2.60) [Ref. 22]. Anyway, Polení’s study attached little importance to a fact that appeared systematically in its domes, as can be seen in the drawing by Piranesi of the Temple of Tosse in Villa Adriana (Fig. 2.61). The dome would be an element to incorporate in the cultured posterior architecture and the Renaissance

Fig. 2.59. Modelisation by Finite Elements of the Pantheon of Agrippa section (Croci).

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The Great Structures in Architecture

Fig. 2.60. Cracking state of the Pantheon of Agrippa dome (Mark).

and the Baroque would make such an extensive use of it that those two styles would be featured by their architecture of convex spatiality. It would also be incorporated in popular architecture with a firmness that would make it irreplaceable as even modest constructions have no straight pieces to construct a flat formwork. Using exactly the same techniques found in Tell al Rimah (Fig. 2.2), people build without a framework nowadays in Afghanistan (Fig. 2.62 and 2.63) and everywhere in the islamic world there is an attempt to recover those old techniques as an identity sign. The complexity of the plans to cover with so scarce resources is illustrated in Fig. 2. 64, having to resort to means as basic as those seen in Figs. 2.65 and 2.66. The results are nevertheless surprising and meticulous even for several plans (Fig. 2.67).

Fig. 2.61. Drawing by Piranesi of the Temple of Tosse, in the Villa Adriana.

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The Invention of the Dome

Fig. 2.62. Building process without framework of a rectangular plan vault and building stages (Souza).

Fig. 2.63. Building process without framework of rectangular plan vault (Souza).

Fig. 2.64. Different building stages for the covering, by means of domes, of a Mauritanian house (Souza).

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REFERENCES OF CHAPTER 2

Fig. 2.65. Domed construction in Afghanistan (Souza).

Fig. 2.66. Domed construction in a refugees camp in Afghanistan (Souza).

Fig. 2.67. Construction domed in several levels (Souza).

44

1. CHASSAGNOUX, A. “Persian Vaulted Architecture: morphology and equilibrium of vaults under static and dynamic loads”. Structural Studies of Historical Buildings IV. Computational Mechanics Pub. Southampton, 1995. 2. CHOISY, A. “Historia de la Arquitectura”. Leru. 3. CHOISY, A. “L’art de Batir chez les Romains”. Forni Editores, París, 1873. 4. ESCRIG, F. “Towers and Domes”. Computational Mechanics Publications, 1998. 5. FERGUSSON, J. “The Illustrated Handbook of Architecture”. Murray, London, 1859. 6. FLETCHER, B. “A History of Architecture”. Butterworths, London. 7. GARCIA BELLIDO, A. “Arte Romano”. C.S.I.C., Madrid, 1972. 8. HEINLE, E. & SCHLAICH, J. “Kuppeln”. DeutcheVerlags-Austalt, 1996. 9. HEYMAN, J. “Teoría, historia y restauración de estructuras de fábrica”. ETSA de Madrid, 1995. 10.IASS. “Domes. From Antiquity to the Present”. Istanbul, Minar Sinan University, 1988. 11. KRAUTHEIMER, R. “Arquitetura paleocristiana y bizantina”. Catedra, S.A. Madrid, 1984. 12.MARK, R. “The Art and Structure of Large-scale Buildings”. MIT Press, 1993. 13.MARK, R. “Light, Wind and Structure”. MIT Press, 1990. 14.MARTA, R. “Arquitettura Romana”. Kappa, Rome, 1986. 15.MINKE, G. “Earth Construction Handbook”. WIT Press, 2000. 16.OATES, J. “Babylon”. Thames & Hudson. 17.ORTEGA, F. “Historia de la Construcción”. Libro Primero. ETSA de las Palmas, Books I, II and III. 18.ROBERTSTON. “Arquitectura Griega y Romana”. Cátedra. 19.SALVADORI, M. “Why Buildings Stand Up”. Norton, N.Y. 20.SCHLAICH, J. & HEINLE, E. “Kuppeln. Aller zeitenAller Kulturen” Deutche Verlags-Austalf, 1996. 21.BALDWIN SMITH, E. “The Dome. A study in the history of ideas“ Princeton University Press, 1971. 22.TERENZIO, A. “La restauración del Panteón de Roma”. La conservation des monuments d’Art & d’Histoire. Paris, 1934. 23.TRACHTENBERG, M. & HYMAN, I. “Arquitectura”. Akal. 24.WARD PERKINS. “Arquitectura Romana”. Aguilar. 25.SOUZA GOIS, M.I. “Cúpulas de Tierra”. Master tesis ETSA de Sevilla. Prof. Escrig, 1995. Not published.

The Hanging Dome

Chapter 3. THE HANGING DOME

Although the dome building tradition was never interrupted while the Roman empire existed, both sides, East and West, continued repeating their usual styles with some small variations. The Western domes were supported by circular or polygonal forms with a high number of sides, which allowed them to go from the drum to the shell without the need of important elements of transition. The groined vault was fundamentally used on square plans. The Eastern solution by means of trumpet shells was always an inelegant way of solving the problem. For that reason it is surprising that the VIth century was born with so many simultaneous innovations. The formal and constructive search was of a fecundity never seen before in such a short time. Simultaneously the Byzantine constructors solved five problems:

As early as 524, Polyeuktos Church began to be built, with a dome of 20 m in diameter and we guess that with a longitudinal scheme reminiscent of later examples. Since this church has not survived it is based on an ideal reconstruction by Harrison [Ref. 4]. We will not spend any time analysing it (Fig. 3.1). The first fully finished example of this kind is Saint Irene in Constantinople, begun in 532 (Fig. 3.2), with an imposing aspect because of its great transverse arches as wide as the lateral naves so as to contain the horizontal forces (Fig. 3.3) and its completely pierced walls similar to those in later gothic cathedrals (Fig. 3.4). Saint Irene is, in addition, a perfect example of a good use of thrusts counteracting by means of two domes,

a) The dome is supported by great arches that left the frontal walls clear enough to be perforated by windows or passages. b) The use of pendentives like a perfect element of transition from a square to a circle. c) The suitable accumulation of domes and vaults to compensate the thrust. d) Constructions of great lightness. e) The support of the dome on isolated points, which guarantees an even illumination and in a certain way dematerializes the weight of the dome, which looks as if supported by rays of sunlight. The mosaic and glazed decoration contributed to that effect.

Fig. 3.1a. Church of Polyeuktos. Ideal reconstruction (Harrison).

Fig. 3.1b. Interior view of the Church of Polyeuktos. Ideal reconstruction (O´Donell).

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Fig. 3.5. Saint Irene, in Constantinople. Structural scheme. (Ortega). Fig. 3.2. Saint Irene, in Constantinople. Section and plan. (Ortega).

Fig. 3.3. Saint Irene, in Constantinople. Inner view.

Fig. 3.4. Saint Irene, in Constantinople. Outer view.

46

Fig. 3.6. Church of the Saints Sergio and Baco. Plan and sections (Ozsen).

The Hanging Dome

Fig. 3.7. Photogrammetric scheme of the Church of the Saints Sergio and Baco (Ozsen). Fig. 3.10. Topographical plan of the dome of Sergio and Baco (Ozsen).

Fig. 3.11. Structural scheme of Sergio and Baco (Choisy). Fig. 3.8. Inner view of the Church of the Saints Sergio and Baco.

Fig. 3.9. Outer view of the Church of the Saints Sergio and Baco.

Fig.3.12. Comparison of sections and floors between Saints Sergio and Baco and Saint Vital in Ravena (Choisy).

one of them having a circular shape 15 m in diameter and the other an oval shape with the dimensions of 12 x 15 m, and of another dome like a cap of a quarter of sphere cap dome in the apsidal model, inherited from the Roman exedras and coming from the palaeochristians apses (Fig. 3.5).

It is remarkable that however difficult it may seem, in every following work the complexity multiplied.

Even if Justinian had not done anything else, he would have deserved a place in History because of this work.

Saints Sergio and Baco Church, built in Constantinople between 527 and 536, have besides a centralised plan, clearly following a Roman model but solved with completely different proposals. In addition to the ambulatory, in the line that had been

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The Great Structures in Architecture

Fig. 3.13. Plan of Saint Vital, in Ravenna (Ward Perkings).

Fig. 3.16. Outer view of Saint Vital, in Ravenna.

Fig. 3.14. Structural scheme of Saint Vital, in Ravenna (Escrig).

Fig. 3.17. Making up of the pieces of the dome of Saint Vital, in Ravenna (Mark).

proposed in Saint Lorenzo in Milan, it used a system of arches that make good use of this double skin for the relief of forces (Fig. 3.6). The dome is in this case ornamented, attaching therefore a great structural importance to the reinforcement ribs, although they are little apparent. The shell is made up of lobes, as can be seen in the drawing in perspective of the photogrammetric restitution (Fig. 3.7) [Ref. 14 ].

Fig. 3.15. Inner view of Saint Vital, in Ravenna (Escrig).

48

The passage from the octagonal form to the circular one is also made by means of pendentives and the

The Hanging Dome

Fig. 3.18. Pieces of the dome and key of Saint Vital, in Ravenna (Mirabella and Lombardini).

illumination achieved by piercing the shell, according to the rules of Byzantine construction (Fig. 3.8), turning weightless the 18 m diameter dome. A feature inherited from the Romans is the modesty of the materials used, even more in this case since even the pozzolanic cement was not available. The whole building is constructed with brick and mortar obtained with the mixing of lime and crushed bricks (Fig. 3.9). This system, though seeming a disadvantage, has turned out to be the salvation of these buildings. Firstly because no later civilization bothered to dismantle what was unusable and secondly because the masonry obtained was elastic enough to adapt to the great movements suffered by the foundations as well as those produced by earth tremors. From 1600 AD to the present time, 89 earthquakes of an intensity higher than six have been registered. All these movements have produced geometric changes, windows breaking and render loosening. Paradoxically, what most damaged this building was the railroad that was constructed closeby in 1870. Nevertheless, during the war of the Balkans it was used as a shelter from the bombing because of its safeness. Fig. 3.10 shows the present state of the geometry and allows sight of its great distortions. Fig. 3.11 is a sectioned perspective showing how the approximately 2,000 tonnes of weight of the dome are absorbed. A later building following a very similar guideline is Saint Vital in Ravenna, also built during the Byzantine period, with a hemispheric cap cover on octagonal plan with ambulatory. Saint Vital is, in a formal way, much more complete for several reasons: it is much higher, reaching 30 m, whereas Sergio and Baco reached only 20 m. Fig. 3.12 shows the comparison between both

sections made by Choisy. It has a more formal coherence that becomes apparent in the plan, peculiarly turned 22.5º with respect to the Narthex (Fig. 3.13) [Ref. 2]. The inner space is of a grandiosity unknown until then, the result of being higher than wide. The different levels and the drum embedded in the cap with great dimensioned windows increase the sensation of height (Fig. 3.14). Instead of pendentives, small trumpet shells have been used simulating sorts of corbel supports that give horizontality to the springing level and allow it to interrupt in a suitable way the verticality of the main buttresses edges (Fig. 3.15). Its outer aspect has a clear volumetry, so legible with regards to what happens inside that such a clarity would not be found again until the Romanesque (Fig. 3.16). In this case, the weight of the cover exceeds 1,000 tonnes, which combined with its height requires a transversal reinforcement that experience has proved strong enough but that is not apparent, and that in the absence of more complete studies allows us to think that implies an almost limiting dimension. Many contemporary analyses, made by fitting methods of calculation, of big constructions such as the Pantheon, Santa Sophia and the great gothic cathedrals, disregard smaller structures like this one that seem far better dimensioned and in a more rational way. Because of its interest, therefore, we add the studies shown in Ref. 11. The perfectly hemispheric cover is about 16 m in diameter and its main particularity is that it is made up of horizontal tubes forming rings from the base to the key (Fig. 3.17). These tubes have approximately 14 cm of side plus a cone of 6 cm, a diameter of 5 to 6 cm and a thickness of 0.5 cm (Fig. 3.18). This allows an almost uniform thickness of the dome of 21 cm (Fig. 3.19). According to this and to the determination of the quality of the

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The Great Structures in Architecture

Fig. 3.19. Section of Saint Vital, in Ravenna (Mirabella and Lombardini).

Fig. 3.20. Deformations of the dome of Saint Vital during the construction. On the left, construction with shoring; on the right, without shoring (Mirabella and Lombardini).

Fig. 3.21. Calculation of efforts and displacements 56º from the key when building by rings (Mirabella and Lombardini).

50

The Hanging Dome

materials, some interesting data have been obtained. Fig 3.20 shows the deformation of the dome with its proportions vertically doctored by 500, for different hypotheses of materials rigidity. This deformation ranges between 0.3206 mm in the case of maximum rigidity and 1.84 mm for maximum flexibility. In the left graphic is considered the construction with framework, whereas in the right one without it and by rings advance without shoring. These are the two possible forms to construct this dome.

Due to the thickness (1.25% of the diameter), the flexions are insignificant and we get a practically perfect membrane state.

The calculation of the efforts and displacements produced by building by rings and without shoring is illustrated in Fig. 3.21 by means of the assimilation to sixteen states of course advance, in the zone corresponding to 56º from the key.

In any case, Santa Sophia is the most important work of Byzantine architecture in which all the technological resources were experimented with, giving rise to one of the most singular constructions.

In any case, the efforts are minimum (0.92 kg/cm2 of compression in the direction of the parallels and 1.43 kg/cm2 in that of the meridians). Neither this tension nor the maximum traction of 0.12 kg/cm2 appearing in other points are critical for the used materials.

Fig. 3.22. Roman basilical plan (Escrig).

Paradoxically, in the calculations obtained, if the hollow tubes had been placed in the direction of the meridians, the structure would have behaved much worse unless it had been built on a framework removed with the mortar well forged, in which case the behaviour would have been similar.

We have already explained how the plan is a combination of the greater Roman constructions: the basilical form of the thermae with its three longitudinal modules having material galleries to hide the buttresses (Fig. 3.22), and the centralized plan of Pantheon type with some transformations (Fig.3.23). In addition we

Fig. 3.23. Scheme of a central plan through an evolution from the basilical model (Escrig).

Fig. 3.24. Superposition of «A» Ste Sophia, «B» Basilica of Maxencius and «C» the Pantheon (Escrig).

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find the previously mentioned innovations: the great transverse arches that serve as supports, the counteracting by means of sectorial domes, the dome resting on points and the thinness of this one due to its brick construction. Figure 3.24 shows the superposition of three main buildings where we can see that «A» and «B» have the same area and «A» and «C» the same diameter between main piers. The result is that of a hitherto unknown greatness (Fig. 3.25). The 31.2 m diameter of the dome, the 76 m of length and the 50 m of height were the greatest continuous volumes ever built before (Figs 3.26 and 3.27). The dome profile was not the present one but that represented in Fig. 3.28 having geometric continuity with the pendentives and being changed in the first reconstruction for the profile of Fig. 3.29.

Fig. 3.25. Engraving of the interior of Saint Sophia, in Constantinople.

The complex with its collection of abutted domes is really difficult to interpret (Fig. 3.30), but it is based fundamentally on a dome that rests on four transverse arches of great magnitude which transition to the circular plan is done by means of pendentives. These transverse arches are not rigid enough to support the horizontal thrusts, they must be supported by auxiliary structures: in the north-western and south-eastern sides with two semi domes that in turn are compensated by other shells of apse, and in the perpendicular sides by four huge buttresses (Fig. 3.31), clearly illustrating all this Fig. 3.32. The problem is that these buttresses were not sufficient and the dome suffered frequent breaking almost from its inauguration and even partial collapse, it had to be reinforced with even greater buttresses (Fig. 3.33) and their great transparent walls had to be blocked up (Fig. 3.34). The dome, being continuous in the beginning, ended up being rebuilt with reinforcing ribs and even so its great elasticity made it so deformable that its aspect is quite irregular (Fig. 3.35) The causes of the bad structural behaviour, nevertheless, must not necessary be only looked for in its design. Also the constructive technique leaves a lot to be desired. The complete building was finished in five years and, to save expenses, the masonry was made up of bad quality brick walls and a mortar with joints of several centimetres and badly set while being loaded. To make matters worse, it is situated in a highly seismic zone. The question would not be why the dome collapsed so many times, but how did it manage to remain standing for so long (Fig. 3.36).

Fig. 3.26. Inner space of Saint Sophia, in Constantinople.

52

Calculations done with modern technologies in this building are contradictory according to the different searchers.

The Hanging Dome

80,90 m.

Fig. 3.27. Section and plan of Saint Sophia, in Constantinople.

According to Mainstone [Ref. 7], the author of the most deep and detailed study of Santa Sophia, the problems originated in the scarce experience in the structural innovation represented by the supporting of a dome by means of transverse arches, having not made a symmetrical counteracting. The semi domes of the E and W sides proved to be an effective system, but the N and S buttresses behaved rather badly, letting the materials slip and triggering the dome denting. No matter how much it was enlarged, because its increase of rigidity caused a thrusts increment straight away and therefore an asymmetrical behaviour of the dome. The regularisation by means of tensors and hoops did not help. He doubts the quality of the foundations and of the capacity of the buttresses, hollowed out to have stairs and galleries, to absorb horizontal thrusts. The present cracks of the dome are not important unless its haunches get more separated.

Mainstone even says that the cracking of the rest of the structure is beneficial because it diminishes the frequencies of vibration in the case of earthquakes. The only real problem that it gives rise to is the progressive inclination of the buttresses. Fig. 3.35 shows the scheme of dissipation of forces according to this author. According to Mark [Ref. 10], who has made a finite elements analysis, the first breaking of the dome in 558 AD, eleven years after being finished and due to 553 AD and 557 AD earthquakes, and its conversion into a dome with a different profile was counterproductive. The first model used the pendentives distributing the efforts very regularly and concentrating them in the corners (Fig. 3.37a), whereas the second model, the

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The Great Structures in Architecture

Fig. 3.28. Initial design of the dome of Saint Sophia (Mainstone).

Fig. 3.30. Volumetric scheme of the domes of Saint Sophia (Mainstone).

Fig. 3.29. Initial and present sections of the dome of Saint Sophia (Mainstone).

Fig. 3.31. Outer view of the domes of Saint Sophia.

Fig. 3.32 Structural scheme of Saint Sophia (Escrig).

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The Hanging Dome

Fig. 3.33 Initial plan and successive reinforcements of the Church of Saint Sophia (Mainstone).

Fig. 3.34. Filling of the tympanums for the reinforcement of Saint Sophia (Mainstone).

Fig. 3.35. Topographical scheme of the domes of Saint Sophia (Hidaka).

present one, because of resting on a plan that fundamentally rests on the transverse arches (Fig. 3.37b), gives rise to important thrusts in the highest part of the buttresses. Apart from the above, the present dome is more stable than the primitive thanks to a greater curvature and to reinforced ribs.

Fossati in the 19th century by means of metallic bundles, hardly had any result in respect of the displacements.

According to Mungam [Ref. 12] the effect of the supporting arches is highly effective only when they all have the same rigidity. In the opposite case, the deformations are proportional to the least rigid and produce flexions in the shell. That is the reason why the considerable reinforcement made by Gaspare

The thesis made by Cereto [Ref. 1] contains revealing data that the dome is elliptical due to the lateral deformation of the southern and northern walls with a difference of 1 m in the main axes and that the collapse of the buttresses is at the present time of 0.8 m (Figs 3.38 and 3.39). When comparing his calculations with the real behaviour of the dome, we lead to the conclusions that the constructive problems began during its erection, due to the sliding of the bricks on

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The Great Structures in Architecture

Fig. 3.36. Descending loads in Saint Sophia (Mainstone).

the mortar and that the counteracting semi domes produce an inward thrust that magnifies the thrust toward the outside of the zone of buttresses whose role is passive, resulting in a non-uniform state of tensions. Figure 3.40 shows the deformation of the original dome calculated both ways, obtaining efforts greater than 5 kg/cm2, and reaching even 10 kg/cm2 in certain cases, which is excessive for this type of construction.

Figs. 3.37a, b and c . Tensional behaviour of the former dome and the present dome of Saint Sophia (Mark).

56

In summary, this is a problematic construction that survives as a result of the will of the successive cultures to keep it standing, and that has served as an authentic structures laboratory. The works of Sinan in the XVIth century owe so much to the solutions of Saint Sophia

The Hanging Dome

Fig. 3.38. Resting plan of the main dome of Saint Sophia (Mark).

Fig. 3.39a Outward collapse of the closings (Cereto).

Fig. 3.39b. Pathologies of the buttresses of Saint Sophia (Cereto).

Fig. 3.40. Deformation of the actual dome in both ways (Cereto).

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Fig. 3.41. Church of the Holy Apostles, in Constantinople. Drawing from a codex.

Fig. 3.42. Church of the Holy Apostles. Reconstruction of the plan (Krautheimer).

Fig. 3.43. Inner perspective, plan and outer perspective of Saint John, in Efeso (Krautheimer).

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The Hanging Dome

Fig. 3.44a and b. Plan of Saint Marcos, in Venice, and structural scheme (Choisy).

that we could rightly state that we are before the prototype work of the eastern architecture, the same as the Pantheon is for the western one. The Byzantines inventions continued in other religious models. Influenced by the approaches of the great monasteries of the Middle East, they generate Latin cross plans covered with successive domes without a special hierarchy.

Fig. 3.45a, b, c and d. Outer view, plan and inner views of Saint Front, in Périgueux (Escrig).

The Holy Apostles Church in Constantinople (540-550 AD) inaugurates this tendency, although there is no longer anything left of it. Figs. 3.41 and 3.42 show what this great construction, which had sequels in

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Fig. 3.48.a. Plan of Saint Peter, in Angoulême (Conant).

Fig. 3.46. Saint Etienne, in Périgueux (Escrig).

Fig. 3.48b. Inner view of Saint Peter, in Angouleme (Escrig).

Venice or the Holy Apostles. Such a long geographic distance in front of such constructive similarity is only explained by a cultural connection that must obviously have been provided by the crusades.

Fig. 3.47. Structural section of Echillais (Conant).

the East but many more in the West, must have been. In effect, Saint John in Efeso, finished towards 565 AD (Fig. 3.43) is an Eastern exact replica. The same thing happens in the West, from Italy, where Saint Marcos in Venice repeats the formula (Fig. 3.44) in the middle of the XIth century, to Aquitaine in France, in the XIIth, where the same plan is used with less skill but more greatness. A good example of this can be found in Saint Front de Périgueux (Fig. 3.45), which plan is almost an exact replica of Saint Marcos in

60

The basic difference that can be observed is that of the illumination solution. Whereas in the Byzantine architecture the dome was an appropriation of the sky and therefore had to be drilled so that the light got in, in the Romanic, closer to the Roman tradition, light is looked for through the walls. It is interesting to observe how the patterns brought by the crusaders from the East recreate the forms but lose the subtlety that all Byzantine architecture and the later Muslim one breathes. Saint Etienne, also in Périgueux (Fig. 3.46), Echillais (Fig.3. 47), Angoulême (Fig. 3.48), Cahors (Fig. 3.49), Fontevrault (Fig. 3.50) or Souillac (Fig. 3.51) are merely some of the scores of examples of churches in the region that, unlike most

The Hanging Dome

Fig. 3.48c. Main dome of Saint Peter, in Angoulême (Escrig).

Fig. 3.48dc. Domes of Saint Peter, in Angoulême (Escrig).

Fig. 3.49.a. General view of Saint Etienne, in Cahors (Escrig).

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Fig. 3.49b. Inner view of Saint Etienne, in Cahors (Escrig).

Fig. 3.51a and b. Outer view and inner view of domes of Souillac (Escrig).

of the Romanics churches, are not covered with a barrel vault. Structurally, in these cases we cannot speak of a contribution, but it is shocking to find this island of Eastern tradition in the Roman Christian whole.

Fig. 3.50 a and b. Plan and inner view of Fontevault (Conant).

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One of the structural advantages of these solutions is that they rest in points and therefore release the walls

The Hanging Dome

Fig. 3.52a and b. Saint Sophia, in Salonica. Outer view and structural scheme (Krautheimer).

Fig. 3.54a and b. Structural scheme and main dome of the Dodrum Camii, in Constantinople (Krautheimer).

Below we will see how other ribbed Romanic expressions were also imported and that Gothic would have not taken place without the existence of the crusades.

Fig. 3.53. Round Church in Preslav. Plan and section (Krautheimer).

of load. These can be pierced with great hollows, the interiors becoming unusually luminous for that time. It also implies that the centring of the loads on the supports, being greater than in the usual Romanic construction, requires smaller buttresses. So, churches were built of only one nave, with hardly any side buttresses. At that moment, the massive construction created in Saint Irene was surpassed, being presaged in other ways by what Gothic art would later do.

Still in the Byzantine ground, the ability for experimentation is inexhaustible. The power to make astronomical investments has been lost, but in a reduced scale new designs are tried. Saint Sophia in Salonica perforates a prismatic drum instead of the dome (Fig. 3.52), although in the interior that is not evident. The Round Church of Preslav (Fig. 3.53) combines all the possible complications: lobed circular plan, circular ambulatory, two levels, hemispheric dome on pierced drums and drum buttresses. The Dodrum Camii in Constantinople, although a miniature, is of an outstanding complexity (Fig. 3.54). At that moment, the dome of continuous mass already had experienced all the possible forms. From that moment only design polishing is left to be done, that is what the Renaissance style did. Meanwhile other possibilities of a completely different nature are opened up, turning the domes into something different: the ribbed dome.

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REFERENCES OF CHAPTER 3

1. CERETO, W. STEFANO, A . & NASCE, V. “Hagia Sophia: A laboratorium monument”. Structural Repair and Maintenance of Historical Building II. Sevilla 1991. Computational Mechanics Pub., Southampton, Pp. 87-95. 2. CHOISY. “Historia de la Arquitectura”. Ed. Leru, Argentina. 3. CONANT. “Arquitectura Carolingia y Románica. 800-1200”. Manuales de Arte Cátedra, Madrid. 4. HARRISON, M. “A temple for Byzantium”. University of Texas Press., Austin, pp.139, 1989. 5. HIDAKA, K et al “Photogrammetry of the Eastern Semi-dome of Hagia Sophia, Istanbul”. Public Assembly Structures. IASS Symposium 1993, Istanbul, Minar Sinan University Pub. 6. KRAUTHEIMER. “Arquitectura Paleocrisiana y Bizantina”. Madrid Manuales Arte Cátedra, 1992. 7. MAINSTONE. “The Structural Conservation of Hagia Sophia. Structural Repair and Maintenance of Historical Buildings III”. Bath, 1993, pp. 3-14. Computational Mechanics Pub., Southampton. 8. MAINSTONE. R. “Hagia Sophia”. Thames & Hudson, London, 1989. 9. MARK, R. “Architectural Technology use to the Scientific Revolution”. The MIT Press, 1993. 10.MARK, R. “Structural analysis of Hagia Sophia: a

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Historical Perspective”. Structural Repair and Maintenance of Historical Buildings III”. Bath 1993, Computational Mechanics Pub. Southampton, pp. 33-45. 11. MIRABELLA, G. & LOMBARDINI, N. “Late Roman Domes in Clay tubes. Historical and numerical study of S. Vital in Ravena”. Spatial Structures. Heritage Present and Future, Milan, 1995. Ed. Padua, pp. 1237-1244. 12.MUNGAM. I & TÜRKMER, M. “Effect of the arches and semidomes on the Statical and dynamic Behaviour of the Central dome in Hagia Sophia”. Spatial Structures. Heritage Present and Future, Milan, 1995, Ed. Padua, pp. 1253-1260. 13.ORTEGA, F. “Historia de la Construcción”. Libro Tercero, ETSA de las Palmas. 14. OZSEN, G.A. “The Structural Evaluation of Kuçuk Ayasofya Mosque”. St. Sergius and Bakhus in Istanbul”. Spatial Structures. Heritage Present and Future. Milan, 1995. Ed. Padua, pp. 1261-1270. 15.ROCA, P., GONZÁLEZ J.L., MARI, A.R. & OÑATE E. “Structural Analysis of Historical Constructions”. CIMNE, Barcelona, 1997. 16.SANPAOLESI, P. “Structure a cupola autoportante”. Palladio. Rome, nº 1-IV, pp. 3-64. 17.SANPAOLESI, P. “La chiesa di S. Sophia a Constantinopoli”. Officina Edicione.

The Ribbed Dome

Chapter 4. THE RIBBED DOME

In search of lightness, economy and an easy construction, many techniques had been experimented with, the preceding chapters is the story of a progression from heavier forms, despite their reduced dimensions, to the minimum weight in the wake of the Pantheon, whose huge room was thought of as the maximum surface to be covered without intermediate supports. That had been possible thanks to the use of a malleable material that nobody was able to reproduce. The Byzantine mortar made of lime and brick powder was of not much use and the stonework, which settled with a geometrical perfection, required a specialisation and means that very few builders could achieve. Villa Adriana, Minerva Temple or Sergio and Baco reinforced their surfaces with groins that proved to be pretty stable. The thousands of Roman groined vaults could collapse in many points,

but most usually kept intact in their pointed diagonals. Observation and logic must have helped a lot to understand that every folding reinforced the surface. But very few times, and no case has survived, a surface was considered as a piece of fabric which is made up of threads that are woven or warped showing the fanciest forms and the most beautiful drawings. No civilization bothered less about the three dimensions than those empires that suffered from vacuum horror and felt forced to fill the buildings with reliefs, shapes, spaces and masses. The Assyrians, the Egyptians, the Greeks or the Romans, the eastern and the western ones, and even the Indians later, invented complex orders that had to cover everything. Only the Muslims, followers of a linear religion that did not even accept the existence of a hell, having a

Fig. 4.1. Dome of the Rock, in Jerusalem (Valcárcel).

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Fig. 4.2. Structural and geometrical section of the dome of the Rock, in Jerusalem (Ortega).

literature traced with only a winding line and representation systems of the simplest geometry, without images and without imitating nature, could conceive what turned out to be the most fecund way for architecture: the fibrous construction, the architecture of resistant lines.

outward or the polychrome plasterwork inward, hiding the structure (Figs. 4.1 and 4.2). Its 20 m in diameter and 25 m of height imposed this type of light construction on a great power that, having military and ideological dominion over an immense territory, did not have its own model to follow.

The discovery of the fact that a form behaves by adapting itself to its inner resistant elements was really a result of intuition, and many centuries had to pass before forming part of the structures theory. Nevertheless, that was the path opened by the builders of the ribbed domes.

That is why the first great mosques, that were constructed making use of previous buildings and with so scarce elements, are so important to explain what happened afterwards. Probably imitating the Rock, all the mosques had a domed space that, in a certain way tried to be more representative outward than inward, at least until the moment when minarets took over from it as the identifying element. The mosques of Damascus, Medina or Cairo would have domes that in no way correspond to the present ones and that did not allow to foretell what would happen. In fact, the appearance of the Abasies in the East and even the coincidence of the literary, scientific and technical renaissances symbolised by Charlemagne in Aquitaine and Harum al Rashid in Baghdad, cannot hide the fact that the source was in Constantinople, which both of them tried to control from the extremes of the civilised world.

Where is the origin of the true ribbed dome that based on brick or stone courses that, logically, can be built with little shoring? Without any doubt, the Omeyas triggered the process. The dome of the Rock in Jerusalem, finished in 691 AD, was made of wood and followed the patterns previously seen in the central Roman plans as that of the Saint Constance Mausoleum, profusely imitated by close constructions such as the Virgin, or the Martirium of Seleucia or Resaffa. But there is something that makes it different. The ribs of the covering framework are copied out of a ship structure, the only reticular precedent of the great convex surfaces. Also, as in the naval version, the ribs were nailed to a wooden planking on which to place the golden metal

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Actually, the constructive technique of some domes of the time, as that of Ibn Tulum in Fustat, dating from 879 AD, follow Sassanid and Byzantine patterns (Fig. 4.3), but that of the great mosque of Kairnan, in 875,

The Ribbed Dome

Fig. 4.3. Mosque of Ibn Julun, in Fustat.

Fig. 4.5. Dome of the Chapel of Villaviciosa, in the Mosque of Cordoba.

Fig. 4.4. Dome of the Great Mosque of Kaiman.

obviously materialises what in the Rock was hidden (Fig. 4.4). Too many pieces of the puzzle have disappeared to speculate about the birth of ribs in the East. What does not leave room for discussion is what happened in Spain, where the deposed Omeyas created a court from 750 AD to the beginning of the millennium, similar in its splendour to that of Baghdad, but much more sophisticated, democratic and cultivated. The Mosque of Cordoba is, for many reasons, the most beautiful jewel since Saint Sophia to the great Romanic cathedrals. But we want to cite it here only because of its five domes on square or rectangular plan, built by Al-Hakem II in 961 to 976 AD, being filigrees in brick that the Gothic style equalled but did not surpass and examples of inventiveness, beauty and efficacy. The dimensions of 10 x 8 m2. of the Chapel of Villaviciosa and its eight ribs permit it to cover some

Fig. 4.6. Main dome in front of the mihrab, in the Mosque of Cordoba.

polygonal spaces in a sumptuous way (Fig. 4.5). Three other domes follow two different models of passage from the square to the octagon by means of ribs. The most beautiful of them, the central one, links alternate vertexes of the octagon (Fig. 4.6). The other two link each vertex to the third one from that (Fig. 4.7). The Real Chapel, traced as the Chapel of Villaviciosa, hidden from visitors and lacking in ornaments is, with its serrated ribs, of an immense dramatism (Fig. 4.8).

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It is not worthwhile to consider their structural behaviour, that is pretty obvious and was never intended to draw anyone’s attention because of its audacity. Nevertheless, such modest constructions have been admired by all their past and present visitors. Basically, they did not deal with a constructive problem, but with an ornamental one. What was the difference among the solutions given to the making of an inlay (Fig. 4.9), of a tile (Fig. 4.10), of a map (Fig. 4.11), of a latticework (Fig. 4.12) or of a piece of fabric (Fig. 4.13)? The consciousness of newness led to the repetition of this model with infinite variations. In Toledo, the small Christ of the Light Mosque, dating from 1000 AD, is a collection of samples of different shapes (Fig. 4.15). Even after the Omeya splendour had faded, the Taifa kingdoms were captivated to the point of affectation by the ornamental potential of such geometrical systems.

Fig. 4.7. Side dome in front of the mihrab, in the Mosque of Cordoba.

The Aljaferia of Zaragoza, dated about 1050 AD, shows a coherence and a proportion that deserve deeper study (Fig. 4.14). Just as thousands of mosques that today, transformed to churches for a different worship, still show those simple domes, made by artisans who were paid for carving different patterns in each work. The remains underlying every village inhabited by the Muslims should be analysed one by one to find the innumerable links that competed with the northern religious architecture and with that from Byzantium, refusing to be integrated in which, once overcome the former prejudices, would culminate in the Gothic style. There are complexes, such as Our Lady of the Olive in Lebrija (Fig. 4.16) or the Huelgas Monastery in Burgos (Fig. 4.17), that we cite only as a justification. Without hesitation, Spain held this tradition practically to the present time with no interruption. Guarini, with the 1668 Saint Lorenzo of Turin, inspired by the Cordoba mosque (Fig. 4.18), or Luis Moya in the XXth century, forced by the poverty of the country that required the recovering of this cheap technique (Fig. 4.19), are examples of the maintaining of something that not even the Christian conquerors of Muslim Spain thought of substituting. As a good example, the magnificent dome of the Room of the Ambassadors in the Alcazar of Seville, which wooden work does not fit in this context, but that, nevertheless, reveals the very high levels of sophistication reached (Fig. 4.20). The other place in which the brick calligraphy reached refined levels was ancient Persia. The Isfahan complex is as rich in dome solutions as any other monument in history (Fig. 4.21). Here we find starred domes (Fig. 4.22), domes of polygonal patterns (Fig. 4.23), domes with the ribs exposed to the outside view (Fig. 4.24), ribs embedded in the mass (Fig. 4.26), domes on pointed transverse arches (Fig. 4.25), very complex transitions from square to polygonal plans (Fig. 4.27) and wooden domes, looking like mushrooms in the

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Fig. 4.8. Dome of the Royal Chapel, in the Mosque of Cordoba.

Fig. 4.9. Nazari escritoire made of wood and ivory marquetry.

Fig. 4.10. Nazari glazed tiles.

The Ribbed Dome

middle of the desert, like a beach full with umbrellas in front of a non existent sea (Fig. 4.28). But Isfahan was only a laboratory in which people worked along nine centuries. The Iranian plateaus were full with the most varied domes, the most pointed of them shored up (Fig. 4.29). Even the rich wooden stalactites formations named mocarabes, seem to have been originated in the complex systems of trumpet shells used to make gradually smaller the span to cover (Fig. 4.30). These wooden mocarabes would culminate in the superb Nazary constructions in Granada (Figs. 4.31 and 4.32), or the fronts in apse or the Iranian and Indian ivans (Fig. 4.33), all of them in full in XIVth century or even later. We find no great dimensions and complex geometries obtained by means of poor materials and without expensive wooden cradles or shoring. The pointed shape of the bigger domes, those ones exceeding 10 m in diameter, are the result of the logical process of superimposing courses, closing them in rings without losing the stability in every round completed (Fig. 4.34). In the smaller ones the hemispherical or the flat forms could be kept thanks to the great thickness that allowed the drawing of the funicular of its inner loads in a parabolic or pointed shape.

Fig. 4.11. Maghrebi nautical map.

Fig. 4.12. Marble latticework of the Caliphal period.

The Muslim art did not have prejudices against the geometries respecting certain proportions and, in that sense, distanced itself in an explicit way from the historic precedents. It does not seem either that the designs were conceived as a whole and we can imagine an intentional accumulation of elements that avoid analysing the plans as proportional and even geometrical tracings. For the same reason they could adapt to unusual plots and reuse previous remains with no scruples, even destroying and freely transforming them afterward. According to chronology, it seems unquestionable that the Muslim architects were pioneers in using the ribs as geometry generators and the structure in the dome solutions. This brought in a parallel way the pointed forms, the transverse arches and every sort of folding and fantasies in the space between ribs.

Fig. 4.13. Almohade tapestry known as the Banner of Navas de Tolosa.

They introduced too the brick disposition as a structural value, constructive and ornamental since, in many cases, it would stay in full view. There are unrepeatable examples of this, as some previously mentioned or those found in Christian constructions in territories conquered to the Muslims (Figs. 4.35 and 4.36). But these discoveries do not end in this point. We have already mentioned that a Christian resistance was opposed to the Islamic expansion that, regarding architecture, materialised in the recovering of the classic patterns.

Fig. 4.14. Dome of the oratory of the Aljaferia, in Saragossa.

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Fig. 4.15. Details of the nine ribbed domes of the Christ of the Light, in Toledo (Velázquez Bosco).

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Fig. 4.16a. Parish church of Our Lady of the Olive in Lebrija, Seville. General view.

Fig. 4.16b. Parish church of Our Lady of the Olive, in Lebrija, Seville. One of its domes.

Fig. 4.17. Dome of the Chapel of the Assumption, in the Huelgas Monastery, in Burgos.

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Fig. 4.18. Main dome and dome of the presbytery of Saint Lawrence in Turin, by Guarini.

Fig. 4.19. Dome in Torrelavega, by Luís Moya (Moya 1956).

Fig. 4.20. Room of the Ambassadors dome, in the Alcazar of Seville.

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Fig. 4.21. Aerial view of the Mosque Aljama, in Isfahan 11th-18th century (Upham Pope).

Fig. 4.22. Starred domes in Isfahan (Upham Pope).

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Fig. 4.23a. Southern dome of the Mosque Aljama, in Isfahan (Upham Pope).

Fig. 4.23b. Northern dome of the Mosque Aljama, in Isfahan (Upham Pope).

Fig. 4.24. Outside of the hemi dome of the Isfahan northwestern ivan (Upham Pope).

Fig. 4.25. Succession of domes in Isfahan (Upham Pope).

Fig. 4.26. Dome of the northern room (Upham Pope).

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Figs. 4.27a and b. Section and view of the Isfahan northern room dome (Upham Pope).

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Fig. 4.28. Mausoleums of Asuan (Upham Pope).

Fig. 4.29a. Dome of the Mosque of Ardestan (Upham Pope).

Fig. 4.29b. Madrasa of Ince Minare, in Konya (Upham Pope).

Fig. 4.31. Dome of the Room of the Two Sisters, in the Alhambra of Granada.

Fig. 4.30. Mausoleum of Al-Safi’I, in Cairo (Upham Pope).

Fig. 4.32. Roof of the Pavilion of the Abencerrajes, in the Alhambra of Granada.

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Fig. 4.33a. Ivan of the Sanctuary of Masjid-i-Jami, in Isfahan.

Fig. 4.33b. South-eastern ivan of the Sanctuary of Masjid-iJami, in Isfahan.

Fig. 4.34. Tomb of Oljeitu, in Sultaneia.

Since 800 AD, the Christians built in the Roman way in the territories bordering with those of their antagonists. From Aquisgran, with centred plan (Fig. 4.37), to the Asturian Preromanic, with basilical plans (Fig. 4.38), like advanced Romanic style as Ste Mary of Ripoll (Fig. 4.39), there are no concessions but to the imitation of the classical style. This would last only until the moment when the balance tips in favour of the Christian side, starting with the reconquest of the conquered territories. Free of complexes, the northern architects do not have any

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prejudice to accept Muslim elements and even hire their builders. In that moment first appears the Modern and later, Romanic that introduces the archivolts in the fronts similar to the eastern ivans, the transverse arches to support the cimborrios and the formerets to reinforce the vaults, together with the pilasters, arches, groined vaults or Roman barrel vaults. Also, the decreasing geometries that link square and octagonal plans and the ribs to build the domes transept. Santiago of Compostela (Fig. 4.40), as many other cathedrals, is

The Ribbed Dome

an example of the Romanic that combine all these elements synthesising the style, a synthesis that will be repeated with few variations in all the rest of the examples, showing that willingness to accept elements from other styles is only the verification of the structural efficiency not of a mental exchange. Naturally, this attitude was gradually relaxing, mainly after the crusades, and the unbelievers were no longer seen as a culture to exterminate, except in the political ground. Their cultural superiority at that moment produced the transformation of western literature, science, technique and the rest of knowledge, architecture included. The austere Romanic changed to be shockingly ostentatious. In this time of splendour, Cluny competed with Medina Azahara, Byzantium or Cairo (Fig. 4.41). Its system of square tiled towers, its domes, its polychromous stones, tapestries, sculptures, its libraries, workshops, schools, investigation centres, etc, were the counterpart to those of Toledo or Cordoba. The extension of its church, with its endless wood of columns, as that of a mosque, its very high dome, more powerful than that of the Rock, shining with sparkles and bells, and its dozens of domes covering the radial chapels were more than a symbol of the power against Mahoma’s religion, but the acknowledgement and appropriation of his culture.

Fig. 4.35. Dome of the Church of the Holy Sepulchre, in Torres del Río in Navarra.

No wonder that discontent and opposition to that ostentation grew among the most clear-sighted intellectuals. What was the use of prevailing on the opposite religion in the most superficial aspects? Why not attack it from deeper grounds such as spirituality and rigor? Islamism was a linear conception, simple, without contradictions or difficulties, without a past. Christianity was complex, deep, inaccessible, contradictory, tormented, and laden with a long history and a doctrine made up of accumulations, legends, saints, heresies and councils. There was something more interesting to obtain of all those circumstances, but the Cluniac monks had hidden it under the decoration. Much has been written about the features that announced the Gothic style during the Romanic: fanvaulting, pointed arches. None of them were determinant for the new style, however evident these elements could be. The key consisted in spirituality and on the effort to synthesise the Christian thinking in an order equivalent to that established by the preceding empires (Ref. 16). So architecture and philosophy developed together to such extent that the scholasticism and the Gothic are indissoluble, so that theological literature was conceived as an almost architectonic structure and architecture was conceived simultaneously by both

Fig. 4.36. Chapel dome of Church of Saint Marine, in Seville.

architects and thinkers, being evident this indissoluble dependency in the Gothic rigor. The leap between the Romanic and the Gothic style was not sudden because the Cistercian order made a bridge toward simplicity in a still intuitive way. But the fact that the abbot Suger of Saint Denis, Saint Abelard and Luis VII coincided in time, together with the great scholastics such as Albert the Great, Saint Buenaventura or Saint Thomas of Aquino, resulted in the aforementioned renovation, which was based on a few principles: a) The inclusion of light as the soul of the built space. b) The order and the proportion of the whole, as an identification of the spiritual power over the chaotic

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Fig. 4.39a. Saint Mary in Ripoll. Plan.

Fig. 4.37. Scheme of the Palatine Church, in Aquisgran.

Fig. 4.39b. Saint Mary in Ripoll. Outer view.

Fig. 4.38. Scheme of Saint Julian of Prados, in Oviedo (Conant).

urban mess on which these building were settled. c) The complete fading of any surface under branches, threads and drawings that move architecture further away from the classicist temptations. d) The vegetal analogy by which the building turned into a living being with a luxuriant foliage and all sorts of living beings crouching in capitals, keys, gargoyles, buttresses, altarpieces, choirs and altars. e) The symbolic transcription in graphical signs of all the concepts, resulting in ceiling roses, stained glass windows, fretworks and labyrinths. f) The use of geometry to replace drawing and the replacement of proportion by trace. For all that, Roman or Byzantine architecture was of no use, and the examples more at hand for inspiration were the Muslim ones. Paradoxically, the two opposite and in a certain way antithetic religions based their architecture upon the same elements, though obviously with very different results.

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Fig. 4.40. Building perspective of the Cathedral of Santiago de Compostela (Escrig).

The Ribbed Dome

Fig. 4.41. General plan and perspective of the Monastery of Cluny (Conant).

Fig. 4.42. Interior of the Cathedral of Durham.

Fig. 4.44. Cathedral of Laon.

Fig. 4.43. Nôtre Dame of Paris.

The Gothic style is luminous and the Islamic one ignores the light, the former is light and the latter heavy, one is rationalist and coherent, the other fantasist and arbitrary.

Fig. 4.46. Vault of the Cathedral of Chartres.

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Fig. 4.45. Cathedral of Toledo.

Fig. 4.48. Vault of the Cathedral of Gloucester.

Fig. 4.47. Vault of the Cathedral of Lincoln.

There is not a scale of values establishing a hierarchy, but the Gothic style brought to the limit the stress capacity of the stones and forced gravity with immaterial effects.

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Fig. 4.49. Chapel of Saint George, in Windsor Castle.

The Ribbed Dome

Fig. 4.50. Chapel of Henry VII, in Westminster Abbey.

If we followed the thread of our text only on the basis of the domes, we would find very little material in the Gothic style. There would be gigantic cimborrios over the transepts, delicate chapterhouses in polygonal shape and side chapels with convex coverings carved in threads. But all this would be embraced by the relentless rhythm of the naves, reaching impossible heights.

The singular elements of the Gothic style are rather towers than domes, even though these have spiral outer shape as huge cypresses or flames that ascend to heaven. Since 1130 AD the Romanic becomes an old fashioned style that does not adapt to the new concepts and must be substituted.

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Fig. 4.51. Interior of the Cathedral of Prague.

Fig. 4.52. Vault of the Church of Annaberg, in Saxony.

Fig. 4.53. Vault of the Cathedral of Segovia.

Fig. 4.54. Vault of the Cathedral of Salamanca.

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The Ribbed Dome

Fig. 4.55. Vault of the transept of the Cathedral of Cordoba (Escrig).

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Fig. 4.57. Chapel of the Constable, in the Cathedral of Burgos.

Fig. 4.56. Chapel of Our Lady, in the Cathedral of Wells.

In the beginning, the Gothic four parts vaults resulting from the groined vaults, result in turn in vaults pretty continuous, as in the case of Durham (Fig. 4.42). But the side walls of central naves were not coherent with the squares of side naves. The moment when the central naves are covered with square patterns, we can assume that they adopt the role of inner domes, though to the outside they are concealed. Nôtre Dame de Paris is one of these first examples of six parts domes (Fig. 4.43), although its tracing does not relate directly to the different heights of the arches keys. Leon is a more perfect case of this kind (Fig. 4.44). In Toledo, the keys are slightly pointed to obtain more convex forms (Fig. 4.45). But the six parts domes were too irregular and soon they were substituted by the four parts ones with a proportion 2:1, as in Chartres (Fig. 4.46) or by the fasciculated ones as in Lincoln (Fig. 4.47). What naturally follows is the multiplication of ribs like a spiders web making the skeleton much more complex. Figs. 4.48 and 4.49 show some stone structures that look rather like slender steel bars or huge tropical leaves full of veins (Fig. 4.50), having beautiful rectilinear patterns (fig. 4.51) or fanciful curves (Fig. 4.52). In Spain they developed the vaults of secondary ribs, which were able to stop the evolution of the imported

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Renaissance styles practically the moment they were substituted by the Baroque structures. The Cathedrals of Segovia (Fig. 4.53), Salamanca (Fig. 4.54) and Córdoba (Fig. 4.55) are examples of it. All these examples refer to cylindrical forms. But if we focus on concave spaces such as chapels and cimborrios, the richness is even greater. As for chapels, we highlight some of the most important: those of Our Lady in Wells (Fig.4.56), the Constable in Burgos (Fig. 4.57) or the Abbey of Batalha in Portugal (Fig. 4.58). In all of them the Islamic patterns are evident. More variety and innovations offer the cimborrios, among which the English ones stand out with dramatic passion. That of Ely, though made of wood, is the most spectacular of all (Fig. 4.59), and the result of suppressing the four main pillars of the transept until getting a polygon 25 m in diameter, whose main framework is shown in Fig. 4.60. Heyman (Ref. 12) has recently done a study of this structure that we find interesting to summarise. Its framework has undergone some transformations over the years, since it suffered serious structural deterioration through being made of wood. In the XVIIIth century, the architect Essex added some elements to the point of turning it into the tangle illustrated in Fig. 4.61. Later on, Walsingham cleared it until getting the polished result that is shown in the Fig. 4.62 diagram. If we analyse the stability of these structures as a spatial net, we can see that, although they fulfil Maxwell’s equation (Fig. 4.63):

The Ribbed Dome

Fig. 4.58. Church of the Abbey of Batalha (Stierlin).

Fig. 4.59. Octagon of the Cathedral of Ely.

Fig. 4.60. Wooden framework of the Cathedral of Ely octagon (Heyman).

Fig. 4.61. Initial design of the Cathedral of Ely octagon (Heyman).

Fig. 4.62. Construction sketch of the Cathedral of Ely octagon. The left side is the invention of Essex in 1760 and the right side the Walsingham solution.

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Fig. 4.63. Perspective of the mechanism of the octagon of Ely.

But Maxwell’s equation is a necessary but not sufficient condition. Besides, the bars have to be correctly distributed. In this case they are not and the whole can get deformed as shown in Fig. 4.64. This would not have happened had the polygon been odd sided; but due to a structural paradox, an even number implies serious damage for its behaviour. Therefore, Essex’s work did not have much use, no matter how many bars were added. In addition, the curved wooden bars indicated underwent some effort due to the supporting of the tower and were unbearable for such a light material. Finally, Gilbert Scott, with less analytic and more technical criteria, got the whole stabilised. His solution consisted of increasing the heavy masonry of the outer circle, in duplicating the number of buttresses and stabilising everything by means of deadweight, what was very suitable against the wind action (Fig. 4.65). Heyman’s text is very detailed and worthwhile consulting. Another impressive cimborrio is that of the Cathedral of Lincoln (Fig. 4.66) which, though having hardly 15 m of side, resolves the square plan with this form until its culmination in a typically English solution. The cimborrio of the Cathedral of Burgos is one of the world’s most beautiful, in spite of its reduced dimensions. The elegance of the ornaments and the effects of the ribs make of it a goldsmith’s work (Fig. 4.67).

Fig. 4.64. Mobility of the mechanism of the octagon of Ely.

3n = b + 6

[4.1]

being n the number of knots and b the number of bars, if 3n < b + 6

[4.2]

the structure is hyperstatic, and if 3n > b + 6

[4.3]

the structure is isostatic and there is a lack of bars, as many as F = 3n – b – 6

[4.4]

If the whole is linked to the outside, the number of links “s” can compensate the lacking bars. Therefore F = 3n – b – 6 – s

[4.5]

So, in a structure similar to that of Fig. 4.63, N = 16, b = 24 and s = 24 And as a result of the equation [4.5] F = – 6 This means that there are 6 extra bars, which is equivalent to saying that the whole is hyperstatic.

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So many are the examples that for a deeper knowledge of the matter we advise you to resort to the references at the end of this text. Nevertheless, before ending this section we should mention the Cathedral of Valencia whose dome, though very modest, has some specially valuable features (Fig. 4.68). It too has an octagonal plan, radial ribs and a height over the nave that doubles the width. It is a late work, already built by the XVth century. But it does not have steel chains nor buttresses (Fig. 4.69). It was the result of a careful study of the loads and the structure that has to conduct them (Fig. 4.70). Tosca made the following description of its tracing: “Being the octagon ABEN and C the vault plan: draw the diagonals, that cross in the centre C, being these the horizontal traces of the diagonal arches and, at the same time, their diameters; draw over one of the diagonals, for instance the BF, the pointed arch BGF, which centres are B and F, to which should be directed their tensions; over the cornisature and over the HI, and the same is to be done in the rest of sides, which arches work like formerets for the vault, being in them and in the mentioned second body a group of windows similar to that of the first body. On the diagonal arches is built the vault, following the tracing of the arch or formeret HLI, which is made of winding brick and fill the hollows ECA, ACB and C of the diagonal arches, which vault, being pointed, form in the middle an

The Ribbed Dome

Fig. 4.68. Transept tower of the Cathedral of Valencia.

Fig. 4.65. Present state of the octagon of Ely outside.

Fig. 4.66. Vault of the cimborrio of the Cathedral of Lincoln.

Fig. 4.69. Outside of the transept tower of the Cathedral of Valencia.

Fig. 4.67. Set of nets of the lantern of the Cathedral of Burgos.

Fig. 4.70. Plan and section of the cimborrio of the Cathedral of Valencia, according to Tosca.

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Fig. 4.71. Vault of the Cathedral of Beauvais.

Fig. 4.72a. Plan by Simón García, copying Gil de Hontañón, of a church with fan-vaulting, in Chapter VI, page 18.

Fig. 4.72b. Church of Villascatín, in Segovia, by Gil de Hontañón.

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Fig. 4.73. Simón García transcribing Gil de Hontañón. Geometrical generation of the plan of a church.

The Ribbed Dome

Fig. 4.74a. Simón García transcribing Gil de Hontañón. Chapter II, page 7.

Fig. 4.74b. Gil de Hontañón. Church of the Vine, in Burgos. Chapel of the monastery.

Fig. 4.75a. Simón García transcribing Gil de Hontañón. Chapter V, page 12. Plan tracing of a church of large dimensions.

Fig. 4.75b. Simón García, Chapter II, page 75. Plan of a church of large dimensions.

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Fig. 4.75.c. Cathedral of Segovia, by Gil de Hontañón.

entering angle corresponding with the line QC: the same thing is made in every eighth side, being concluded the work with much beauty and firmness enough, almost without needing an extra abutment, as I show in the following form:

allowed them to advance on the basis of previous projects. In any case, they counted on a firm knowledge of geometry. But the massive and superficial structures that they constructed were too difficult until the XVIIIth century.

Firstly, the vault that is placed over the transepts AC and BC and fill the hollow, which plan is the triangle ACB, has enough abutments with the collateral vaults corresponding with the triangles ACE and the one of the other side; because having such a high point is little its thrust, against which have very enough resistance the aforementioned collateral vaults, singularly when the plan has 6 or 8 sides, or even more”.

Nevertheless, the Gothic structures had an advantage over any other: they were linear, so that their study reduced to that of the balance of forces and loads.

We wonder how with such poor analytical means as we suppose existed in the Middle Ages, these challenges could be assumed with such precision. We know that the Romans, much more advanced, fully trusted the accumulation of experiences that

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Paradoxically, this did not even require some knowledge of geometry. It was enough making thread models, models that almost always can be flat, since Gothic naves or radial chapels can be reduced to the study of parallel or polar plans. That is why what in the XIXth century was resolved with the help of a static graphic that demanded skill in drawing, could before be experimented with a thread suspended between two extremes being the springing supports. From that point balance was achieved by means of weights, to get all the forces passing through the interior of resistant members. When Gaudi built the Holy Family

The Ribbed Dome

he did but echo the Gothic tradition that still underlies that zone of the Mediterranean. The theory of proof and mistake does not prove valid in works of such a huge size and as much investment. Otherwise, it cannot explain that the great constructions were made without minor precedents. It is true that there were big disasters, but they were not proportionally bigger than those suffered nowadays by perfectly calculated works. Whoever visits the Cathedral of Beauvais is impressed by the challenge of those 46 m high and fully holed naves (Fig. 4.71). It seems as if the slightest breeze or the minimum earth tremor could make fade all that glasswork as if it were made of smoke and, nevertheless, there it is, proud after having undergone all the disgraces that the Genesis threw against those ones that wanted to build a Ziggurat to ascend to heaven. Beauvais reached 156 m at its highest point and so challenged arrogantly all its neighbours who attempted to achieve similar feats in their towers. Its collapsing should have been considered a fair punishment. But Ulm, Strasbourg or Colony succeeded in materialising that challenge in stone, though after waiting for some centuries.

Fig. 4.76. Name of the elements of a fan-vault.

In any case, there is no question that the thousands of Gothic churches and cathedrals resulted in an exercise of calculation and risk and, as stoneworking had its own rules that were transmitted without exceeding the gremial limits, dimensioning too had some rules that you should not infringe and that gave sufficient safety coefficients which surprisingly were not excessive. Maybe between 3 and 5, which in masonry work is very advisable. The existence of written treatises on dimensioning, maybe those written in code, is beyond any hesitation, but they are but few and little known. The most important of all is that by Rodrigo Gil de Hontañón, so complex that it must be a compilation of many traditions. It is worthwhile to spend some time on these contemporary books of Gothic structures. The Gil de Hontañón’s manuscript is dated between 1544 and 1554, evidently out of the period we are studying in this chapter. But, since it is a synthesis of all the knowledge gathered to the moment, it can be thought that some centuries ago construction followed those criteria. Its name is “Treatise of architecture and symmetry of the temples” and is exclusively about dimensioning. Maybe it is the first book about structures of history. It consists of three different parts: a) Calculation of the surface of temples. b) Establishment of the general tracing. c) Formulas for the dimensioning of the structural elements, pillars, buttresses, vaults and towers.

Fig. 4.77. Simón García transcribing Gil de Hontañón. Cap. IV, page 105. Project of tower for the Cathedral of Salamanca.

For the calculation of the surface of temples, he used demographic criteria. For the tracing, he simultaneously based on the theories of the classic proportion as an analogy of human body and the systems of the Gothic tradition for the geometrical tracing. Fig. 4.72 shows the great resemblance to page 18 of Chapter VI in Gil de Hontañón’s book to the church of

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Villacastin tracing, dating from 1529, as an example of the proportional tracing that is also illustrated in Fig. 4.73. Fig. 4.74 shows an outline of the geometrical tracing of page 7 in Chapter II and its resemblance to the Church of La Vid in Burgos, dating from 1522. Fig. 4.75 shows the equivalent for a cathedral and its materialisation in the Cathedral of Segovia. As for the dimensioning, he based it on the churches of hall, which always used dome shaped vaults, following the outline of Fig. 4.76. The dimensioning rules advised were: Circular pillars:

HL A 2 D pillar diameter. H height of the nave. L span of the nave. A length of the stretch. D

[4.7]

Buttresses: C

2 2 H 3 3

¦N

;

A

c 2

C buttress side. H buttress height. ÓN addition of the halves of the ribs that take hold of the buttress lengths. A buttress core.

Fig. 4.78a. Rule n.1 for the dimensioning of buttresses, according to Gil de Hontañón.

Ribs: Bond-stone arch Transept arch Secondary ribs Arch of shape

L/20. L/24. L/28. L/30.

This is of use if the pillars height equals the span of the stretch. If it is bigger, this will increase or diminish in the same proportion. Being a flat vault, this dimensions should be increased. If the span of the stretches is different, the media should be used. Keys:

Q

P

¦R ¦S

[4.8]

Q weight of the key in quintales (about one hundred pounds). P weight of the transepts in quintales. ÓN length of the sustaining elements in feet. ÓS length of the sustained elements in feet. Towers:

E 92

H 2

C

HA A 2

H 4

[4.9]

Fig. 4.78b. Drawing of the Rule n.1

H height of the tower. A width of the tower. E thickness of the wall. C thickness of the buttress. Fig. 4.77 shows the project of the Cathedral of Salamanca.

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Fig. 4.79a. Rule n.2 for the dimensioning of buttresses, according to Gil de Hontañón.

Fig. 4.80. Rule n.3 and its interpretation.

Besides, the manuscript spends some time in a series of graphic considerations to the dimension of the buttresses that correspond to different kind of arches, according to certain rules illustrated in Figs. 4.78 [Rule I], 4.79 [Rule II], 4.80 [Rule III] and 4.81 [Rule IV]. Rule I is only of use for circular arches, Rule II for flattened ones, Rule III allows the dimensioning of buttresses of variable section, whereas Rule IV is valid for every sort of arch.

Fig. 4.79b. Drawing of the Rule n.2.

Since that moment, some other treatises about structural matters have been written, up to the present time. We want to highlight Durand’s rule for the dimensioning of buttresses for every kind of arch, which due to its simplicity was the most used (Fig. 4.82).

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We may wonder about the precision of these methods and their justification. The answer is rather complex. They cannot be disdained as simplifications made by people who ignored calculation, or magnified as the elixir of experience. To be true, their dimensions could have been improved making them depend on the materials quality and the geographical zones. But in short, these buildings have survived in spite of disasters and wars, which cannot be said of some present constructions dimensioned in the limit. The ribs based construction was one of the great discoveries of architecture, and although it was buried by the builders of the Renaissance, the Baroque and the classic style, it once again reached a predominant situation with steel and concrete, making possible nowadays the largest known structural designs.

Fig. 4.81. Rule n.4.

Fig. 4.82. Rules of Sanabria and Derand.

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The Ribbed Dome

REFERENCES OF CHAPTER 4

1. ACLAND, J.H. “Medieval Structure: The Gothic Vault” University of Toronto Press, 1972. 2. ADAM, E. “L´Architecture Medievale II”. Petite Biblioteque Payot. 3. BARRUCAND, M. & BEDNORZ, A. “Arquitectu ra Islámica en Andalucía”. Taschem, 1992. 4. CLIFTON - TAYLOR, A. “The Cathedrals of England”. Thames & Hudson, 1986. 5. CONANT, K. J. “Arquitectura Carolingia y Románica 800-1200”. Ediciones Cátedra, 1982. 6. DODDS, J.D. “Al-Andalus. Las Artes Islámicas en España”. Edi. El Viso, 1992. 7. ESCRIG, F. & PÉREZ VALCARCEL, J.”La Mo dernidad del Gótico. Seis puntos de vista sobre la arquitectura medieval”. Servicio de Publicaciones de la Universidad de Sevilla, 2004. 8. ETTINGHAUSEN, R. & GRABAR, O. “Arte y Arquitectura del Islam 650-1250”. 9. FITCHEN, J. “The construction of Gothic Cathedrals. A Study of Medieval Vault Erection”. Oxford at the Clarendon Press, 1967. 10.GIMPEL, J. “Les Bátisseus de Cathedrales”. Editions du Seuil, 1961. 11. GOMEZ RAMOS, R. “La Iglesia de Sta. María de Sevilla”. Universidad de Sevilla. Arte Hispalense nº 60, 1993. 12.HEYMAN, J. “Teoría, historia y restauración de Estructuras de Fábrica”. Instituto Juan de

Herrera. E.T.S.A. de Madrid, 1995. 13.HOAG, J.D. “Rodrigo Gil de Hontañon. Gótico y Renacimiento en la Arquitectura Española del siglo XVI”. Xarait, Madrid, 1985. 14.HUERTA, S. “Diseño Estructural de Arcos, Bóvedas y Cúpulas en España. 1500-1800”. Tésis no Publicada. ETSA Madrid, 1990. 15.JIMENEZ MARTIN, A. “El Arte Islámico”. Historia del Arte nº 15. HISTORIA 16. 16.MARK, R. “Experiments in Gothic Structure”. MIT Press, Cambridge, 1992. 17.MICHELL, G. “Architecture of the Islamic World. Its History and Social Meaning”. Thames & Hudson, 1978. 18.PANOFSKY, E. “A Gothic Architecture and Scholasticism”. Latrobe, 1957. 19.RUIZ DE LA ROSA, J. A. “Traza y Simetría de la Arquitectura”. Universidad de Sevilla. Serie Arquitectura nº 10, 1987. 20.SIMSON, Otto von “The Gothic Catedral. Origins of Gothic Architecture and the medieval concepts of order”. Princeton Univ. Press, 1956. 21.UPHAM POPE, A. “Persian Architecture”. Thames & Hudson, 1965. 22.VIOLLET LE DUC, E. “Entretiens sur l´Architecture” 2 vols. París: A. Morel, 1863-1872. 23.WILSON, C. “The Gothic Cathedral”. Thames & Hudson, 1992.

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Chapter 5. A PLANIFIED REVENGE. UNDER THE SHADOW OF BRUNELLESCHI

While the fiction of the Empire was alive, all over Europe there was a certain stylistic coherence that materialised in the Romanic and kept on ruling the architectonical interventions. From England to Sicily or from Galicia to Germany, the Roman patterns, reproduced in shafts, capitals, circular arches and spherical domes, meant an outline of orders and ornaments renowned as classical. This unity survived for longer than the Empire itself, in spite of the fact that Charlemagne tried to repromote it under his military and moral control. His heritage, torn apart by his children who consolidated a systematic confrontation among the European regions that is still dragging on, and the economic fact that the Empire was fictitious and that every little portion of its territory had to survive on its own initiatives, extinguished the last embers of that unity. Since that moment, new nationalisms were born, echoing protohistorical periods of legends and epic poems free of the influence of the Roman dominion. The Gothic style was born with a huge strength in the North of France and matured with its interventions, which seemed impossible given the scant capitalisation of the cities. This ostentation of autonomic fervour spread quickly all over a geography that, not having roots of its own, saw in that imaginative style that had no prejudices and was free in its interpretation, a good chance to turn it into its own creation. Despite its formal unity, its determinist techniques and its similar results, it was possibly understood that the localist ornaments provided enough freedom to make people claim a disconnection of the classic rules, pagan and oppressive. The Gothic style, despite the many transformations undergone along the history, can be traced crouching in periods of political centralism that necessarily required again a calling for the imperial system until the extinction of those periods. The XIXth century, shaken by the Napoleonic dominion, resources, from the literature to the plastic arts, to the nationalist dream of the medieval Renaissance. The XXth century itself resorts to decorativism in any of its known aspects (Art Noveau, Modernism, Secession, etc), while the new nations are taking shape and history is being rewritten. It is common

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knowledge of the huge difficulties faced by the great pioneers of new international architecture to see their works recognised before the end of the First World War, which brought a certain stability to the nations' borders. But despite its undeniable appeal, the Gothic style did not shake the foundations of the birthplace of Classicism. It was impossible for the central zone of Italy, mainly the regions of Toscana and Campania, to renounce its own culture to join the commotion of the vegetal architecture. The Classicism had been invented there, had been planned from Rome and had proved able to unify cultures as distant as the Persian and the Mauritanian. The Italian Romanesque always had a luminous and tidy appearance that could not be found in Santiago or in Maguncia. The different orders kept a certain purity and the marble slabs showed a Roman cut. In summary, the skill was not lost. In fact, the Eastern Empire survived until the XVth century and the permeability was absolute. The Gothic style crossed Italy leaving but a patina of modernity that could not conceal the classical substrate. Only the region of Lombardy, always reluctant to join the Empire, accepted the new style with a relative conviction. Venice’s case is different. Venice was a patchwork of different cultures, gathered thanks to their commercial vocation. Venice could not be unaware of what was happening elsewhere, since it lived on others’ illusions. It constructed Saint Marcos, a literal copy of the Saint Apostles Church in Constantinople, with a passion that extended to the building of the sumptuous medieval palaces and the Renaissance churches of the initial times. The Renaissance, or the Modern Style, as was then named, wanted too to be a local self-assertion connected to a story that, on this occasion, was perfectly documented. Any dusted off classical text was celebrated with great acclaim from the intellectuals that were making that national consciousness. In an opposite way to that proposed in the Middle Ages, in this case unification did not have a military but an economic nature, showing through it the deep renovation and the knowledge of the control

A Planified Revenge. Under the Shadow of Brunelleschi

mechanisms. It was a coincidence that in that moment three giant personages, who were at war among themselves, had to fight against their own disintegration. The fact that Charles V, Francisco I and Henry VIII confirmed in the new style their longing for universality, facilitated its diffusion. The Renaissance could have been only a trend, had it not coincided with that historical moment. In symmetry, the Eastern Empire had also crumbled and a tribe of conquerors had succeeded in rebuilding it with a dimension never seen before. The Ottoman Empire was forced to straight away invent another universal style to have under strict control the dispersion to which tended Egyptians, Persians and Byzantines sharing the same yoke. It was not necessary to look for very long. The great works of the VIth century built by Theodosius were claimed as undeniable autochthonous precedents. Maybe they were not as rich as the Islamic filigrees, but their colossal dimensions matched the magnificence of the Empire. Finally there was a mixing that nowadays gets us amazed at its unity, its beauty and its technique. The Italian Renaissance architects themselves never hid their admiration for the constructive quality of those monuments and even Leonardo’s notes show that he had found in them an inspiration for his proposals. The Renaissance was no more a western matter. At the same time, a similar explosion was taking place in the Far East, as well as some time later in India or much sooner in Mesoamerica with a culture so advanced as the Aztec one, unfortunately destroyed in only a night by a swineherd from Extremadura. Even in Central Africa there was a phenomenon unthinkable of in that continent except in the Nile proximity. When we talk about the Renaissance, we will not refer to Vitrubio’s resurrection note to the collectors of ancient pieces of marble. We want to focus on the necessity of creating a sphere of proposals that are recognisable for their unity and language and that appeal to precedent Roman constructions. In the moment when Florence decided to be the driving force behind the classic Renaissance, this city was not the most powerful in the Italian peninsula. Milan, Sienna and, of course, Venice were ahead. Neither in Florence were there old remains to take as a model. No big works that stimulated the self-esteem had yet been undertaken. Nevertheless, it was here where that national consciousness took shape. May be literature, under Dante’s and Petrarca’s leadership, was the trigger of the new classicism. In painting it was Giotto and in sculpture the Pisano’s school. All of them have a medieval background that floats over their great innovations. That is why we must set 1400 as the magical date in which the decision on the competition to build the doors of the Florence’s Baptistery separated the vocations of Ghiberti as a sculptor and Bunelleschi as an architect. Undoubtedly, the latter was superior in both fields and finished drawing

Fig. 5.1. Saint Vital, in Ravenna (Escrig).

Fig. 5.2. Saint Lawrence, in Milan (Escrig).

together the best artists of the time around him. Donatello, della Robia, Massacio and Alberti were his fervent admirers. That is why it was a logical decision to elect him to project and build the most important work of the XVth century. Italy in that moment, as in previous years, was fully ready to assume a new important role. In architecture, the great works kept on being the representative churches. Pisa had, in the XIIIth century, the most qualified monument, behind the Roman works that survived in the ancient capital city and in Ravenna (Fig. 5.1) or Milan (Fig. 5.2). Its classical ornaments and its two domes would be a reference to imitate until the arrival of the Baroque. What was left of the Gothic period was several churches: Saint Francisco in Asisi (Fig. 5.3), Saint Petronio in Bologna (Fig. 5.4), Saint Anthony in Padua (Fig. 5.5) and Saint John and Saint Paul in Venice (Fig. 5.6). The great Gothic works were

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Fig. 5.3. Saint Francisco, in Asisi.

Fig. 5.6. Saint John and Saint Paul, in Venice.

Fig. 5.4. Saint Petronio, in Bologna.

Fig. 5.5. Saint Anthony, in Padua.

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to be started very late. The Cathedral of Milan hardly had got its galleries finished in the XVIth century (Fig. 5.7). In the Monastery of Pavia the great architects of the XVth century still worked (Fig. 5.8). Only in the Cathedral of Sienna, finished in the XIVth century, can we find the perfectly delimited foundations of Classicism (Fig. 5.9): semicircular arches, pilasters with Corinthian capitals, transverse arches and a dome over the three naves by means of resting on an hexagonal plan (Fig. 5.10). Sienna was an economical power that could afford that luxury, a counter power to Florence that tried to do the same but failed, because Florence also started building a gigantic Duomo under the leadership of the main sculptor and architect of the time, Arnolfo of Cambio (Fig. 5.11). Here you could be amazed at the sight of the Saint John Baptistery, constructed in the XIIth century, that could be built to scale on the new church (Fig. 5.12). Thus it was decided that the shy projected nave would be ended with a powerful octagonal rotunda and three counteracting thick arms. The dimension of the walls is explained by the need of avoiding the serious variations that started appearing in the ambitious works of Sienna and even in Giotto’s Campanile, beside Saint Mary of the Flowers. It is obvious that the failures of Sienna were seen by the Florentines as successes, whereas they did not agree about the modifications to do in Arnolfo’s first works. Since the middle of the century scale models and proposals followed each other. The rivalry among the three competing architects is well known: Talenti, Orcagna and Lapo Ghini. The final result was decided by a popular vote and was immortalised in a picture (Fig. 5.13). Being the three of them, mostly sculptors with little experience in architecture, it was no surprise that they could not solve the problem of building an octagonal dome 42 m in diameter, 50 metres from the floor. To cap it all, the lengthening of the main nave and its conversion from

A Planified Revenge. Under the Shadow of Brunelleschi

Fig. 5.7. State of the Cathedral of Milan in 1773 (Creve).

Fig. 5.9. Cathedral of Sienna (Escrig).

Fig. 5.8. Monastery of Pavia (Heindereich and Lotz). Fig. 5.10. Cathedral of Sienna (Stierlin).

five modules to four, generated some thrusts stronger than expected, that had to be counteracted with metallic struts (Fig. 5.14). We have spent time with these descriptions so far from the Renaissance period because they lead us to deduce the debt that Brunelleschi owed to the past. When he won the competition in 1420 he was a sculptor with a vast culture who had visited and studied the main Roman remains. That is why his first important work, the portico for the Hospital of the Innocent, is of so refined a classical style (Fig. 5.15). Talenti had invented a complete shoring system that was excessively expensive and the successive master builders did not go above the drum, the spring line, because they did not find a satisfactory solution to keep going. The common proposal of Brunelleschi and Ghiberti was based on two fundamental contributions: the possibility of lifting the drum twelve metres more and the solution of vaulting without wooden cradles. It was, in that moment, a complete madness that was based on the knowledge of the Pantheon and the Temple of Minerva Medica, but had to be resolved with a medieval shape and in keeping with the contract clauses.

We can think that the genius of Brunelleschi was universally recognised but at that moment he was one architect among many who competed in Florence doing all type of tasks. Brunelleschi, in the confusion of a competition in which nobody proposed a solution of common sense, elaborated a scale model that scrupulously respected the image assumed by the city reflected in paintings and sculptures, by which it was remunerated. During three years there was a continuous debate on the way to close that gigantic crater located at the top of the church. His ability was demonstrated by being able to show with his model that it could be constructed without a wooden cradle. The silk guild had to trust this architect of hardly forty years, although Ghiberty and Battista d´Antonio were designated to help him. In order to avoid surprises a contract with twelve clauses was signed to define the shape, the constructive materials, the thickness, the number of ribs and the building systems. This contract probably reflected Brunelleschi’s own choice. In spite of that, there is a shortage of information about this phase in which the works of the cathedral were continued, never seen before for a monument of its dimension. It seems

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Fig. 5.11. Superimposition of the former and final projects of Saint Mary of the Flowers, in Florence (Borsi et alt.).

Fig. 5.13. Painting by Andrea Bonaiuti, including the project of Saint Mary of the Flowers chosen by popular consensus.

Fig. 5.12. Saint John Baptistery, in Florence (Escrig).

Fig. 5.14. Metallic struts in the nave of Saint Mary of the Flowers.

that Brunelleschi, very self-confident and mistrusting his competitors, worked with the maximum of secrecy. The workers themselves had to be lodged in the work place and the plans were destroyed as soon as they were used. If the dome had a basically medieval aspect, also the atmosphere in which it was being built seemed medieval. Therefore, it is not surprising that everything that has been written on the dome is based on suppositions. Maybe Mainstone is the person who has described the difficulties of this work in greatest detail, perhaps because he saw it with an engineer´s eyes.

Fig. 5.15. Portico of the Hospital of the Innocent, in Florence (Escrig).

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Starting from the knowledge that the dimensions and the shape were imposed, we are going to describe the components and solutions of so singular a work. In the first place it was built on an octagon 42 metres in inscribed diametre, placed 55 metres high from the

A Planified Revenge. Under the Shadow of Brunelleschi

(Escrig).

Fig. 5.16. Final sketch of the dome of Saint Mary of the Flowers.

Fig. 5.18. Sketch of the ribs of Saint Mary of the Flowers (Battisti). Fig. 5.19. Building set of the dome of Saint Mary of the Flowers

Fig. 5.17. Profile tracing of the dome of Saint Mary of the Flowers

(Battisti).

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ground, on a drum of 12 metres (Fig. 5.16). The first 14 metres were made of stone and the rest of brick, reaching a height from the ground of 90 metres. The profile is that of the “quinto acuto” pointed arch, which consists of dividing the diametre in five parts and taking the fourth segment as the centre of the curvature (Fig. 5.17). It results in a cambered form with a slope of 67º in the key that turns into 62º because of the existence of an oculo 5 metres in diametre. The dome is formed by eight main ribs of circular tracing, a radius of 36 metres and 8.8 metres in width and sixteen meridian ribs on the sides with an elliptical tracing 1.3 metres in width (Fig. 5.18). In addition, there are 9 parallels that together with those in the base and the crowning make up a very rigid space reticule. All that is complemented with two laminar sheets of cylindrical tracing, an inner one of 2.20 metres and another external of 0.73 metres, with a gap between them of 5.17 metres (Fig. 5.19). All this results in a weight of about 7 tonnes per square metre of dome unevenly distributed. The total weight of the structure is 20,000 tonnes.

breakage or destruction did not affect the dome. But they had a stabilising role regarding the rheological and seismic behaviour. Some hypotheses use the criterion that the author wanted to build a circular dome inserted in the octagon and therefore the courses had to be successively closed so that they acted as compressing rings. This hypothesis complicates immensely the construction method since floating centres are needed for the tracing of the surface and, in addition, the courses are not flat since they are the result of the intersection of a cone with an elliptical cylinder (Fig. 5.21). However complicated this hypothesis could be, it has prevailed over the other as the official one. With respect to the masonry, the workers must have been placed on climbing scaffolds to lay the bricks. On the outside, with a thickness of 0.73 metres, as well as in the interior, with a thickness of 2.2 metres, where these scaffolds would advance hanging on the void (Fig. 5.22), anyone will find it very difficult to explain how the big bricks could be properly laid. The most admissible hypothesis is the simplest and has been described in one of my previous works.

The merit of Brunelleschi consisted of constructing it without the aid of wooden cradles nor shoring. Never before had a building of these dimensions been constructed in that way. And he could not have known of other smaller domes, such as that of the Treasure of Atreo, that were made by means of courses, or some of the Eastern constructions, so he was forced to use the knowledge of the Gothic techniques that did have a solution for these problems. If only the ribs were sustained by a framework, the rest could rest on them. But in this case the ribs were excessively high and too heavy. We know that in the years previous to the building order, the architect had been in Rome studying the classic remains. From the Pantheon he learned the value of the ribbings to lighten the weight of the whole, from the Domus Aurea how to solve an octagonal dome, from the Temple of Minerva Medica how to turn an octagonal plan into a circular one and how to insert ribbings in its interior to make the interspersing of masonry in between easier. From the Caracalla Thermae he learned the techniques of massive construction and the advance of courses. We must take into account though that Florence had contacts with Eastern artists due to the commercial exchange, and it was possible that some craftsmen had moved to Tuscany to enjoy its temperate climate and its standard of living; the disposition of the bricks in the dome was too similar to that of the old Eastern Empire. The fact of using a pointed profile helped much in the solution, once loaded with a heavy lantern.

It is documented that for the construction Brunelleschi levelled the sandy area around the Arno to make the working tracing and to measure to life-size scale. Few could interpret those lines drawn with lime on the ground and the wooden stakes, except for the author and his collaborators. If the author wanted to keep secret his method he succeeded since nobody could find it out later. From the life-sized drawing he drew the curves of the formerets that were going to be the framework for one of the ribs. Having a constant radius, he only had to make sections of a easy-to-use length and place them in their point, verifying their geometry from platforms at the height of the drum crowning (Fig. 5.23). That way the ribs could be made with a gradual increase of height and a radial tracing of the brick courses. By means of the level, the points at the same height could be linked to the horizontal brick courses, placing in the established intervals the reinforcements of the inner ribs to link the two sheets. The bricks of these two shells must logically be horizontal since there is no simple geometric method to draw them up radially. And after all, what Brunelleschi was constructing was a Gothic dome of ribbings (Fig. 5.24), that is to say following the patterns established by the authors of the previous century tracing. But still there are other advantages. On this work, four metres thick in the base and rather thicker in the key, along its horizontal cut the workers could walk and do their task at the level of their hands without having to crouch or use sawhorses (Fig. 5.25). This is the most effective form to make good use of the possibilities of the construction.

Nevertheless, we can only conjecture about the following procedures. The first 8 metres, made of stone did not cause problems. They practically continued the drum and were used to intersperse all kind of horizontal tying elements (Fig. 5.20): building stones with metallic staples, wood belts, metallic bars. Their effectiveness is in question when we consider that their

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What is more, at the edges, all kinds of safety elements could be placed as handrails or similar. The accidents during this work are not documented, most possibly because they were very few. The materials would be lifted by means of machines fixed to the

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Fig. 5.21. Building progress of the dome of Saint Mary of the Flowers, according to the floating centres hypothesis (Borsi et al.).

corbels that perforated the dome and were used later in the rendering and in the tile roof. There is evidence of the ability of the authors of the work to invent mechanisms because nowadays some of them are still in the Duomo Museum (Fig. 5.26). Along the first few metres the stability of the whole would not depend on the collaboration of all the parts, but as this became necessary the courses would be closed before advancing to the following. The mortar used at the time, with a thickness of up to five centimetres took much time to harden, this made it a necessity to advance in horizontal layers instead of vertically in order to be able to walk along the previous layers. The period of one week calculated by some historians to place a brick course all around the octagon must be lengthened due to the more than eight courses that had to be laid to reach the height of the workers waist. This would mean that they could spend two months walking over previous courses. As for the structural behaviour, much has been said about the thrusts produced in the different rings. If the profile had been hemispheric, there would have been tractions in the base greater than those that could have been absorbed by the brick and the mortar (Fig. 5.27). Having been pointed, that proportion produces compressions in all the mass. All this would happen with a circular plan. As the plan was octagonal, the

Fig. 5.22. Hypothetical scaffolding system of the dome of Saint Mary of the Flowers (Battisti).

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Fig. 5.23. Building proposal by the author (Escrig).

Fig. 5.26. Winch in a drawing by Francisco de Giorgio (Battisti).

edges of the cylindrical sheets resulted in an arch like behaviour of the great corner ribs. Finally we have returned to the calculation of the whole like that of a dome with eight ribs propped up in the key. The stability of the whole is based on the behaviour of those Gothic ribbings. If these do not move the stability of the whole is not in danger. Much importance has been attached to the spring bundles, among other things because they were mentioned in the contract and were in fact made. About this matter several theories have been formulated too: a) A first theory says that these elements are traction rings compensating the outward thrusts. Not having a circular plan, this is not true and the curving disposition that appears in so many plans of the base can perfectly have been invented. In order to rigidise the traction on a straight element, a curved cable makes the result worse because it introduces flexions. b) A second one says that they play a checking role for the whole working. Before the dome is damaged, these controllers would break. These were expensive controllers that could have been substituted by a simple rope. Fig. 5.24. Ribs according to Salvadori (Escrig).

c) A third theory says that they serve to stabilise each one of the stretches that, due to their complicated network of ribs and internal arches, also undergo horizontal thrusts. In this case they have to be necessarily straight. d) A fourth one simply says that they do not serve for anything and can even be detrimental because they force to behave as a whole something that has to have a certain independence.

Fig. 5.25. Hypothetical climbing way without scaffolding, according to the author (Escrig).

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e) We put forward another theory that is not in the bibliography. The bundles were in the contract and they were to be placed in the beginning of the works, when Brunelleschi still did not have enough prestige to change the criteria of the contractors.

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From Leonardo to Fontana, including Michelangelo, many gave their opinion, although nobody did anything to prevent them. The studies of Blasi demonstrate that the evolution of them have much to do with the temperature changes (Fig. 5.31).

Fig. 5.27. Tractions in the base of the dome of Saint Mary of the Flowers, in the hemispherical and pointed hypotheses (Escrig).

Fig. 5.28. Present cracking state of the dome of Saint Mary of the Flowers (Borsi et al.).

In practice we can see that the cracking that appeared in the centre of the stretchers and in the joining with the ribs confirms the most sceptical hypotheses (Fig. 5.28). Each rib works at this moment in an independent way, however it was as the initial planning. The analytical verifications that have been done by every investigator are interested in their own hypotheses and tend to demonstrate them. Thus the calculation by finite elements of Kato, who considers the masonry a homogenous and continuous material. Out of this calculation we deduce that the traction in the base of the whole barely reaches 1 tonne, a practically insignificant one (Fig. 5.29). The same author also analyses the advantages of the pointing and comes to the conclusion that the “quinto acuto” used is the ideal combination between its own weight and the displacement in the base (Fig. 5.30). The large amount of writing generated by those cracks is amazing, in contrast to the few on the construction.

Another important aspect is the fish bone disposition that confirms that the Eastern techniques of construction, absolutely ignored or at least not used by the westerners, were known then(Figs. 5.32 and 5.33). As we have already mentioned, Brunelleschi must have known them well, since there are many similarities with works placed along the route of the caravans. Mainstone mentions the Oljeitu Mausoleum for its great resemblance and for being dated at the beginning of the XIVth century: octagonal plan, pointed brick dome, double skin linked by ribs and a great dimension (a crowning 54 m high, 24 m in diametre and the same “quinto acuto”). Too many chances to have been discovered separately (Fig. 5.34). The fish bone disposition would be used in practically all later brick works (Figs. 5.35 and 5.36) and even in some of the stonework (Fig. 5.37) until the systematic application of the chambered domes of Byzantine origin. Considering the importance attributed to the great dome as the architectonical beginning of the Renaissance, we have given enough hints as to its lineage and position as a landmark and the culmination of the medieval proposals. The cathedrals of Milan and Pavia tried to emulate what presumably was the recovery of the monumental Gothic. Fortunately, Brunelleschi surpassed what could have been only a technical challenge and began to design with great rigor and modesty other works in which the technological challenge did not exist but that set out an intellectual adventure. Nevertheless, in the resolution of other smaller domes he always used ribbings except for those with circular profile. The solution of the Old Chapel of Saint Lawrence is similar to that of Sergio and Baco in Constantinople, apart from the fact that it has twelve ribbings instead of sixteen (Fig. 5.38). The new aspects were the ornaments and an order that, from then on would be common place. The existence of the four horizontal levels is clearly evident. The first one, that of the naves, the second one, on the first cornice, that of the transverse arches, the third one that of the drum, replaced here by sectioned plans of the dome, and the fourth one that of the dome (Fig. 5.39). In the Pazzi Chapel, with a similar technique, he timidly sets a Greek cross plan (Fig. 5.40). In the churches of Saint Lawrence (Fig. 5.41) and Holy Spirit (Fig. 5.42) he perfected the basilical plan until giving it the invariable features that have survived to date as examples of religious architecture. It cannot be said that these were technical adventures, but they emphasised proportion, therefore putting an end to the geometrical style of the Gothic.

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Fig. 5.29. Analysis by Finite Elements of the Dome of Saint Mary of the Flowers (Aoki and Kato).

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Fig. 5.30. Analysis of different shapes for the same dome (Aoki).

Fig. 5.31. Present dome cracking (Blasi and Mark).

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Brunelleschi would still do new contributions in his approach to classicism, renewing the contributions about the temples of circular plan. Saint Mary of the Angels recovered the thermal type of the paleochristian baptisteries and opened a fruitful new path in the following years (Fig. 5.43). It seems that it was Alberti who suggested to him to leave the square and take the compass. The proposals to extend and enlarge innumerable churches spread all over Italy would be born here. Michelozzo in SS. Anunciata crowns a basilical nave with a rotunda identical to that of the Temple of Medical Minerva (Fig. 5.44). Alberti in Saint Francisco of Rimimi (Fig. 5.45), never finished as shown in the medal of Mateo of Pasti (Fig. 5.46), tries to crown a new temple with another gigantic rotunda. Bramante does the same thing in Saint Mary of the Grace in Milan, with 20 m in diameter (Fig. 5.47).

Fig. 5.34a. Oljeitu Mausoleum, in Iran (Escrig).

Fig. 5.32. Drawing by Antonio de Sangallo the Young, of the dome fish bone disposition.

Fig. 5.31b. Structure of the dome of the Oljeitu Mausoleum Fig. 5.33. Fish bone disposition in Isfahan (Upham Pope).

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Fig. 5.35. Fish bone building of a Vatican room (Souza, not published).

Fig. 5.36. Drawing by Antonio de Sangallo the Young of a minor dome for Saint Peter’s, built in fish bone (Mainstone).

Fig. 5.37. Dome of the chapel of the Anet castle, built by Philibert de l’Orme in 1549 (Blunt).

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Saint Mary of the Flowers would be the new incentive for the new great transept domes: Saint Petronio in Bologna, not finished (Fig. 5.48), the Cathedral of Pavia, with the intervention of Bramante (Fig. 5.49) and the Cathedral of Milan, by Francisco de Giorgio (Fig. 5.50) from previous drawings by Leonardo (Fig. 5.51). Also Alberti had opened the doors to a new model, the Greek cross plan, this time perfectly defined, in which the building is projected in a pyramidal shape towards the pinnacle of the dome. Saint Sebastian in Mantua, with a dome 17 m in diametre that collapsed just after being constructed (Fig. 5.52), or Santa Maria delle Carcerei in Prato, by Giuliano de San Gallo, are the quattrocentist prototypes of this proposal made by Brunelleschi. Very usually Leonardo has been considered an innovator for having proposed the bubbles plans (Fig. 5.54). But the complexity of these designs hindered the clarity that the new style looked for. On the other hand, the characteristic impatience of the inventor made him leave any project that required much time and he was never able to go beyond the paper stage in architecture. Nevertheless, the most gifted architect of the transition the XVth century, Bramante, had taken everything that had been done, said or drawn and would open the full Renaissance in its entire splendour.

Fig. 5.38. Old chapel of Saint Lawrence, in Florence (Battisti).

At the end of the XVth century the ideal synthesis had been reached on the basis of some principles objectively enunciated: a) Reinvention of Classicism having as a reference the Roman times. b) Elaboration of a formal language usable as a universal language with strict rules of application. c) Definition of a catalogue of basic models to be used according to their function. d) Recovery of a technology alternative to the Gothic based on the wall and not in the rib. e) Importance of the introduction of urban-planning and definition of the urban space from architectonic elements. To get all this, the synthesis of all the plastic arts, the valuation of the drawing and the perspective for their character of virtual definition of the work to construct, and the rising of the artist to the rank of an intellectual, were counted on.

Fig. 5.39. Axonometry of the old chapel of Saint Lawrence, in Florence (Heindenreich and Lotz).

In the Renaissance buildings we are going to find certain constant elements that make them easy to identify: 1) The unity of the building. This is something that defines the Agrippa Pantheon and that is not repeated until the Shrine of Saint Peter in Montorio.

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2) Focality. Of a longitudinal type towards the back of the nave, of a central type towards an inner point or of a vertical type towards the key of the dome by where a flood of light can enter.

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Fig. 5.41. Church of Saint Lawrence, in Florence (Heindenreich and Lotz).

Fig. 5.40. Pazzi Chapel, in Florence (Borsi et alt.).

Fig. 5.42. Holy Spirit Church, in Florence (Stierlin).

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Fig. 5.43a. Drawing by Brunelleschi for Saint Mary of the Flowers, in Florence.

Fig. 5.43b. Drawing by Leonardo of Saint Mary of the Flowers.

Fig. 5.44. Proposal by Michelozzo for the extension of the Anunciata chapel, in Florence (Heindenreich and Lotz).

Fig. 5.45. Work of Alberti in Saint Francisco, in Rimimi (Heindenreich and Lotz).

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Fig. 5.46. Alberti’s project for Saint Francisco, in Rimimi.

Fig. 5.47. Saint Mary of the Grace, in Milan (Escrig).

3) Luminosity. In spite of the wall based structure, the constructive systems allow the opening of great hollows in the high parts of the naves and drums.

The structural and functional advantages of these types are the following:

4) The domed ending as an essential element for the control of the inner space and for the identification of this from the outside. The dome recovers the oculos, lost in the Gothic style, which is ended by a lantern. 5) Modulation, that is used in the ground plan and in the elevation and replaces the regulating plan of the Gothic. The orders are of use for the signalling of the modules. This means in practice three types with many variants that Brunelleschi constructed as if he was writing a treatise on architecture in a stone similar to that written in paper by Alberti: a longitudinal plan as that of Holy Spirit, a Greek cross plan as that of the Pazzi Chapel and a circular plan in Saint Mary of the Angels.

Longitudinal Type: - Hall plan with buttresses embedded between the lateral chapels. - Barrel vault in the main nave with lunettes that concentrate the loads on the pilasters. - Perfect buttressing of the dome with hardly any need for additional reinforcement of the supports. - Use of low quality materials. - Illumination at several levels. - Continuity of the outside order towards the interior. - Transverse arches connected with the masonry. Greek cross type: - Descending balance of the loads with no need of buttresses.

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Fig. 5.49a. Cathedral of Pavia (Stierlin).

Fig. 5.49b. Model of the Cathedral of Pavia .

Fig. 5.48. Peruzzi’s proposal for Saint Petronio, in Bologna .

- Planned as an autonomous urban element and as a unitary inner space. - It allows an organic growth in draughtboard form, in the cases where the space unity is turned down. Circular type: - It is a highly symbolical form except for the Christian faith that finds in it an excess of Christian references. - It has many structural advantages when buttressing on or linking. - It allows implementation of the old or Eastern constructive systems.

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One of the features of the Italian Renaissance is the absence of towers that destroy or hide the unity of the whole. The high domes replace them. This feature can not be extrapolated to other regions.

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Fig. 5.50. Proposal by Francisco Giorgio for the cimborrio of the Cathedral of Milan (Pedretti).

Fig. 5.51. Leonardo’s sketching for the cimborrio of the Cathedral of Milan.

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Fig. 5.52. Alberti’s project for Saint Sebastian, in Mantua (Heindenreich and Lotz).

Fig. 5.53. Saint Mary of the Imprisoned in Prato, by Giuliano de Sangallo (Escrig).

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Fig. 5.54a, b, c and d. Bubbles domes for centralised plan proposed by Leonardo.

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Fig. 5.54e, f, g and h. Bubbles domes for centralised plan proposed by Leonardo.

Fig. 5.55. Bubbles domes for longitudinal plan proposed by

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Fig. 5.56. Dome sketches for the Milan Duomo by Leonardo.

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REFERENCES OF CHAPTER 5

1. AOKI, T., KIDAKA, K. & KATO, S. "Structural Stability and profile in the Dome of Sta. Mª del Fiore. Florence". STREMA. Computational Mechanics Pub., Southampton. 2. ARGAN,G.C. “Brunelleschi”.Electa. 3. BENEVOLO, L. “Historia de la Arquitectura del Renacimiento”. Taurus, Madrid. 4. BLASI, C. & GUSELLA, V. "Historical evolution of the Cracks of the Brunelleschi´s Dome in Florence: Experimental Data Analysis and Numerical Structural Model". Computational Mechanics Publications, Southampton. 5. BORSI, F. “Leon Batista Alberti”. Electa, Milan. 6. BORSI. "Filipo Brunelleschi: 1377-1446. La naisance de l´architecture moderne". L´Equerre, Paris. 7. BULGARELLI. “All´ombra delle volte: architettura del quatrocento a Firence e Venecia”. Electa, Milano. 8. CABLE, C. "Brunelleschi and his perspective panels". Vance Bibliographies, Monticello. 9. CASTEX, J. "Renacimiento, Barroco y Clasicismo". Hª de la Arquitectura 1420-1720”. AKAL, Madrid. 10.DOUMATO, L. "Filippo brunelleschi". Vance Bibliography, Monticello. 11. FANELLI, G. "Brunelleschi". Scala, Firence. 12.HEIDENREICH, L.H. & LOTZ, W. “Arquitectura en

Italia 1400-1600”. Manuales Arte Cátedra, Madrid. 13.KATO, S., HIDAKA, K. & AOKI, T. "Structural Role of the wooden ring of the dome of STA. Mª del Fiore in Florence". IASS Symposium 1988, Istanbul. 14.KLOTZ, H. “Filipo Brunelleschi: The early works and the medieval tradition”. Academy Ed, London. 15.MAINSTONE, R. “Structure in Architecture: History, Design and Innovation”. Ashgate Publishing Ltd, U.K. 16.MARK, R. “Architectural Technology”. MIT Press, Cambridge, Mass. 17.MILLON, H.A. & MAGNANO, V. “The Renaissance: from Brunelleschi to Michelangelo: The representation of Architecture”. Thames and Hudson. 18.MURRAY, “The outline of the Italian Renaissance”. London. 19.PEDRETTI, C. “Leonardo Architetto”. Electa, Milan. 20.PRAGER, F. & SCAGLIA,G. “Brunelleschi: Studies of his technology and inventions”. MIT Press, Cambridge, Mass. 21.ROSSI, P.A. “Le Coupole del Brunelleschi”. Bologna, 22.SAALMAN, H. "Filipo Brunelleschi. The Coupola of Sta. Mª del Fiore". London. 23.SALVADORI, M. “Why Buildings stand up”. Norton, N.Y.

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Chapter 6. THE CENTURY OF THE GREAT ARCHITECTS

Brunelleschi and Alberti had placed architecture on a level that only required enough wealthy patrons and experienced architects. Both circumstances happened to to be found together in the dawn of the XVIth century in the times of their great successors: Bramante, Michelangelo, Vignola and Palladio. As for the patrons, Rome had again become the capital of the Christian world after the return of the Pope from Avignon and his pretension to turn it into the greatest city of the known world. Alberti convinced Nicolas V of the the idea that the choir begun by Rosellino behind the old basilica of Saint Peter, lacked the greatness that the initiative of the construction of the new temple of Salomón exiged (Fig. 6.1). Nonetheless, this initiative did not succeed because his successor, Pablo II, insisted on continuing the same project so that it

Fig.6.1. Rosellino’s project for the Basilica of Saint Peter (Millon and Magnano).

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was finished in the Holy Year 1475. But it was Julio II, who after his arrival to the pontifical throne in 1503, fully changed the planning. Although his personal architect was Giuliano de Sangallo, the order was made to Donato Bramante, an experienced architect but with almost no work built in Rome; it is curious that his most remarkable piece has a minimum dimension: a shrine. This Tempieto of Saint Peter in Montorio is the paradigm of the new classic perfection. Belonging to the Doric order, placed on a peristyle rotunda and covered with a hemispheric dome, it was an exercise of formal precision that could only be built in the dimension of a small model (Fig. 6.2). All the architecture of the Renaissance can be found in this small piece.

Fig. 6.2. Bramante’s projecto for the Shrine of Saint Peter in Montorio (Millon and Magnano).

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Fig. 6.3. Bramante’s drawing of the Saint Peter’s project adaptation to the pre-existing construction (Thoenes).

Fig. 6.5. Fra Giocondo’s project for Saint Peter’s (Thoenes).

When he received the order to continue the building of the great basilica he was therefore an artist who had earned the respect of people even greater than that earned by his teachers. His problem was that he had to start off from a plan that gave shape to his own plan and from a pre-existing building that indicated the axis. In his hand dated drawing dating from 1505, we see at the same time the plan of the former Saint Peter, the part constructed by Rosellino and his first idea of adaptation to the pre-existing construction (Fig. 6.3). Contrary to what is the traditional opinion, Bramante never had the idea of constructing a temple of Greek plan, not even of making use of some of Leonardo’s proposals; he proposed to spin the plan ninety degrees. But his 1506 project is well represented by the innumerable drawings of his assistant Peruzzi. There is no doubt about the fact that Giuliano of Sangallo, his competitor, tried an alternative proposal of a centralised plan based on Bramante (Fig. 6.4), whereas Fra Giocondo showed a clear preference for a basilical one (Fig. 6.5).

Fig. 6.4. Sangallo’s project for Saint Peter’s (Thoenes).

The great contribution of Bramante, which all the alternative proposals would conserve, was to bevel the hard corners of the part constructed by Rosellino to

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Fig. 6.7. Parchment plan solving the rear part of Bramante’s project, in composition with a Peruzzi’s elevation (composed by Escrig). Fig. 6.6. Foellbach’s hypothesis of Bramante’s second project adapted to the the paleochristian plan and to that built by Rosellino (Millon and Magnano).

extend the size of the dome and thus give it a diameter equivalent to the three naves, as had been done in Florence and Pavia. That, and the idea of making some projected pendentives of a spherical trapeze type, are already found in the first outlines of Fig. 6.3. The project is so reasonable and perfectly adapted to the plan of the paleochristian basilica, as much in width as in length, as is shown in the Foellbach hypothesis (Fig. 6.6). The plan in parchment (Fig. 6.7) seems to be the last attempt to establish the definitive plan of the back part. Whereas the medal of Caradoso illustrates the dome concept (Fig. 6.8), maybe on the basis of a proposal that has not reached our times and that we know thanks to an idealisation by Serlio (Fig. 6.9) which makes good use of the parchment plan to make it equivalent to Giuliano’s proposal. There are no surviving important plans of Bramante’s project, all we know is that he wanted to crown the basilica with a hemispheric dome identical to that of the Pantheon. For that, his effort was aimed at the creation of a base, firm enough to support the gigantic thrusts that were supposed to be generated. Fig. 6.10 illustrates in a disordered way this attempt in Bramante’s drawing and Fig. 6.11a and b, the aspect

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Fig. 6.8. Caradoso’s medal of the prior solution (Lotz).

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Fig. 6.9. Serlio’s interpretation of Bramante’s dome (Kraus).

Fig. 6.11a. Drawing by Bramante of the dome support (Thoenes). b. Evolution of the shape of the great pillars in the Saint Peter’s successive projects for the transept: Bramante, Peruzzi, Rafael and Michelangelo (Bruschi).

Fig. 6.10. Bramante’s approaching to the final plan (Thoenes).

of what he tried to do. Nevertheless he had great problems in respect of this aspect, and it was naturally Michelangelo, permanently in conflict with him, who revealed the cracks that appeared in the great pillars of the transept as they rose. Bramante died in 1514, just a year after a Florentine pope, Leon X, and the

architects who followed him, disciples or admirers of the teacher, made the necessary changes to make possible his great dream (Fig. 6.11c). Giuliano, Rafael or Peruzzi reinforced the main pillars and consolidated the basilical plan (Figs. 6.12, 6.13 and 6.14). Antonio of Sangallo inherited the direction of works at the death of Rafael in 1520, and during ten years he elaborated for the first time a complete and unitary project to solve the difficulties of a dome that nobody had dared to design. The drawing by Scorel illustrates the state of works at this moment (Fig. 6.15), whereas those by Heemskerck, the state in 1532 (Fig. 6.16). The ambitious work advanced slowly in the middle of a succession of different popes, changing architects, political and religious problems and changes of ideas. In 1520, Lutero was excommunicated for preaching against the simoniacal uses of Church, the financing of the works of the Vatican being a main objective of those. In 1527, the sacking of Rome was made by the armies that defended the religion. In 1529 Soleiman laid siege to Vienna after Belgrade had already fallen. It is no wonder that between 1521 and 1534 the works

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Fig. 6.12. Giuliano de Sangallo’s project to continue Bramante’s work (Millon and Magnano). Fig. 6.14. Peruzzi’s project to continue Bramante’s work (Thoenes).

Fig. 6.13. Rafael’s project to continue Bramante’s work (Lotz).

Fig. 6.15. Drawing by Scorel of the state of the vatican works in 1520 (Lotz).

practically stopped. The only thing that Sangallo could do was to study the problem, to take notes and to prepare itself for better moments. Meanwhile the Italian architectonic panorama had much changed. The examples of Bramante and Alberti had many followers and the temples of central plan are the alternative trend to the basilical plans. Cola of Caprarola began the Church of the Consolation in Todi in 1508, although the cupola was not started until 1568 and was not finished until 1606 (Fig. 6.17). Its 15 m in diameter and its unitary space confer on it a moving inner spatiality. Antonio of Sangallo the Old began the Chapel of the Madona of Saint Biagio in Montepulciano in 1518, which was built quickly and finished in 1529 (Fig. 6.18). In 1564 the only one of its two projected

bell towers was finished, summarising thus Bramante’s ideal that a church had to be preceded by two towers. Although it was only 12 m in diameter, it was the first great dome finished in the XVIth century. Rafael, in addition to the Chigi Chapel, had already experimented with Alberti’s scheme in Saint Eligio, on a plan by Salustio Peruzi (Fig. 6.19), though with a minimum dimension of hardly eight metres. Bernardino Zaccagni began the Madonna della Stacata in Parma in 1521, a symbiosis between the last two models, since it combined the cylindrical tubes with apsidal conoidal vaults and he even left planned four towers framing the dome (Fig. 6.20) or four cupolas instead. Although it only had a 14 m span, it was too big a work for that architect, who was replaced by Sangallo,

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Fig. 6.17. Church of the Consolation in Todi, by Cola of Caprarola (Escrig).

Fig. 6.16. Drawings by Heemskerch of the state of the works in 1532 (Millon and Magnano).

Fig. 6.18. Chapel of the Madona in Biagio, by Antonio of Sangallo the Old (Tafuri).

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Fig. 6.19. Drawings by Rafael for the Church of Saint Eligi (Tessari).

Fig. 6.20. Madona della Stacata in Parma, by Bernardino Zacagnii (Escrig).

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Fig. 6.21. Madona della Campagna in Piacenza, by Tramello (Lotz) (Escrig).

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Tramello and Corregio. In 1531 the work must have been very advanced since Parmigianino was asked to paint the dome. Tramello began the Madonna of Campaña in 1522 (Fig. 6.21), that repeats the previous model but replaces the conoidal vaults with sections of cylindrical vault and really materialises the corner domes. In this case it was a Nordic decorative model, as it corresponded to Piacenza, but that complicated the centralised plan a lot. The ideal of a centralised design, as planned by Brunelleschi in Saint Mary of the Angels, was the

Roman temple, and for reasons that have not been clarified, although it seems that the stability of the ground had an influence on the decision, the Florentine pope Leon X put out that model to a tender to build the church of Saint John of the Florentines in Rome, in which Rafael, Sangallo the Young, Peruzzi, Julio Romano, Vignola and Sansovino took part, the last winning the tender (Fig. 6.22). This happened in 1518 and the work was not executed. But it generated a bibliography for fifty years worth of proposals. Better known was the project of Sangallo (Fig. 6.23). Peruzzi’s project can be seen in Fig. 6.24. Rafael’s, in Fig. 6.25,

Fig. 6.22. Sansovino’s project for Saint John of the Florentines, in Rome (Millon and Magnano).

Fig. 6.23. Antonio de Sangallo’s project for Saint John of the Florentines (Millon and Magnano).

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is rather similar to the project that was being analysed as a solution for the Saint Peter dome. In 1559, Michelangelo, then architect of Saint Peter, was asked to also offer his plans (Fig. 6.26). The temple was never constructed but it was an example for successive accomplishments, as that of Sanmichelli in Saint Bernardino and the Madonna of Campagna, both in Verona (Figs. 6.27 and 6.28). The afore mentioned details help us to understand the transformations that Saint Peter was going to undergo

in the hands of Bramante’s successors. Rafael and Antonio of Sangallo the Young still were designing the basilical plan. But the first project of Michelangelo was already fundamentally centralised. In spite of the reluctance that, according to Vasari, he showed before the enormous Sangallo project, without this the final project would not have been possible. Both Sangallo and Peruzzi had collaborated with Rafael, Peruzzi left us the most valuable information about the constructive advances of the work and Sangallo provided us with a

Fig. 6.24. Peruzzi’s project for Saint John of the Florentines (Millon and Magnano).

Fig. 6.25. Rafael’s project for Saint John of the Florentines (Millon and Magnano).

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Fig. 6.26. Michelangelo’s project for Saint John of the Florentines (Argan and Contardi).

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Fig. 6.29. Sangallo’s project for Saint Peter’s (Bruschi).

Fig. 6.27. Saint Bernardino in Verona, by Sanmicheli (Lotz).

detailed project (Fig. 6.29) that was materialised in one of the wood scale models, real works of art of the architecture (Fig. 6.30). It seems that both architects, competing permanently for more than ten years, were forced to work in tandem by Clement VII, eager to reduce the initial budget at any price. Also, the first project of Sangallo did not succeed, but his rigorous comparative studies with the Pantheon revealed an attempt to materialise, in a reduced version, Bramante’s project. Fig. 6.31 shows the section of the Pantheon with measurements and three possible solutions for Saint Peter numbered in the drawing, whereas Fig. 6.32 shows the result of solution 3. From 1530, both architects chose a centralised plan solution, with a portico of access of huge dimensions. Peruzzi’s project can be traced through a series of drawings (Fig. 6.33), whereas Sangallo’s later reaches a full definition as a centralised one, which would not be clearly seen until the order to make the scale model in 1539, after the death in 1536 of Peruzzi who Pope Paul III had every trust in. Maybe that was the reason why Sangallo was forced to adopt the Greek cross plan (Fig. 6.34). His final project can be seen in Fig. 6.35.

Fig. 6.28. Madona della Campagna in Verona, by Sanmicheli (Lotz).

In this project, there are some aspects of great interest. We have said that Sangallo knew Bramante’s project well, as well as its Roman and Florentine precedents. He knew that the stability of the Pantheon

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Fig. 6.30. Sangallo’s project model for Saint Peter’s (Lotz).

Fig. 6.32. Sangallo´s Solution n. 3 of the previous drawing for Saint Peter’s (Bruschi).

Fig. 6.31. Sangallo’s authographed drawing with the Pantheon measures and several solutions for Saint Peter’s dome (Bruschi).

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dome was based on the thickness of the base and that the “quinto acuto” of Saint Mary of the Flowers increased its stability and allowed a construction without a wooden cradle. That is why his last project had such a Gothic profile and had only a ribbed sheet . The drum was reduced to the minimum to hide the excessive height of the dome and the outside was reinforced with two floors with columns, imitating two drums superimposed. The dome is one of rotation with 32 ribs that can be seen from both inside and out, and are connected by horizontal rings. Thus, besides not needing wooden cradles, the construction would start with these ribs, making up something similar to a

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Fig. 6.33. Preparatory drawings by Peruzzi for Saint Peter’s project (Millon and Magnano).

reticular structure, as must have been done in the Pantheon.

Fig. 6.34. Preparatory project to the final one by Sangallo for Saint Peter’s (Lotz).

The other main aspect refers to the definition of the profile, a little extravagant (Fig. 6.36). Not agreeing with any of the precedents of great domes, he planned a section of 42 m in diameter and 30 m of height. That was the result of projecting on a plan the curve resulting of the Fig. 6.37 tracing. It is a curve with a big resemblance to a catenary that gathers different advantages: it hardly has any flexion on its profile and does not generate horizontal thrusts in the base. Let’s say that Sangallo got, in an empirical way, an ideal curve. The comparative result between the domes of Bramante and Sangallo is that of Fig. 6.38.

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Fig. 6.35b. Drawing by Antonio of Sangallo for Saint Peter’s.

Fig. 6.35a. Final project by Antonio of Sangallo for Saint Peter’s.

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Fig. 6.36. Sangallo’s dome profile proposal (Bruschi).

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Fig. 6.39. Graphical definition of the pendentives in a Bramante’s drawing for Saint Peter’s (Thoenes).

Fig. 6.37. Sangallo’s dome profile geometrical tracing (Millon and Magnano).

Fig.6.40. Forces model with a Fig. 6.41. Force lines obtained from the previous model chains scheme (Kraus). (Kraus).

Fig. 6.38. Comparison between Bramante’s and Sangallo’s domes (Mainstone).

Fig. 6.42. Michelangelo’s modifications to the works made by his predecessors (Argan and Contardi).

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Fig. 6.43. Michelangelo’s project for the Saint Peter’s plan, according to Duperac (Argan and Contardi).

Fig. 6.44. Michelangelo’s project elevations, according to Duperac (Argan and Contardi).

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Fig. 6.45. Autographed drawings by Michelangelo, for the Saint Peter’s dome tracing (Argan and Contardi).

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Fig. 6.46. State of the drum at the time of Michelangelo’s death (Mainstone).

After the death of the architect in 1546, the divine Michelangelo succeeded him in his post, always in conflict with everybody and disagreeing with his predecessors and contemporaries. Before starting that chapter, it would be useful to analyse the two domes proposed to then. According to Serlio’s drawing, which compiled the contemporary schemes of Bramante (Fig. 6.9), it seems that we are faced with a mimetic reposition of the Pantheon. According to Krauss and considering that the dome rests on some projecting pendentives (Fig. 6.39), the most problematic section is that corresponding to the drum (Fig. 6.40), which must be reinforced with buttresses instead of columns (Fig. 6.41) as Della Porta made later. Bramante did not have a solution to finish the Basilica and his project was so academic that it did not guarantee the stability of the supports even before the dome was built. The only experimented element was the lantern, because it was an identical copy of the Tempieto of Saint Peter in Montorio. As for the rest, without the help of Pellegrino, Peruzzi and Sangallo, he would have had problems, since he was more worried about other ordered works. Michelangelo expressed in those years his doubts about Bramante’s technical ability and honesty. As for Sangallo’s project, we are going to differentiate between that confirmed by his hand in 1538 (Fig. 6.29) and that from 1546, the date of conclusion of the scale

Fig. 6.47. Wooden scale model presented to Pope Paul III (Argan and Contardi).

model in wood (Fig. 6.30), in which graphical expression of Fig. 6.35 can be seen that the dome base has been reinforced by means of a periphery colonnade. But most probably, this project, signed the year of his death, was made by his collaborators, mainly by Antonio Labacco who used to boast about

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presented to the Pope. Vasari and Duperac were guarantors for his project, to the point that when in 1565 the continuator of the works, Piero Ligorio, wanted to change Michelangelo’s design he, was immediately dismissed. The character of the Divine can be found from his arguments with the ecclesiastical hierarchy. When he was asked to explain his project, he answered that the mission of the Church was to look for the money, whereas he would be in charge of the rest.

Fig. 6.48. West wing at work, by Michelangelo (Argan and Contardi).

being the author. Neither the drawings of Fig. 6.36, nor its expression in the sheets of Fig. 6.35, have the polished design characteristic of one of the best architects of the Renaissance. As both projects have nearly the same profile, we can only differentiate them by the existence or not of ribbings. The first decisions taken by Michelangelo were drastic. Twenty-two years after Bramante’s death, he could be generous with his memory and make good use of it to change the decisions of his successors: “It is true that Bramante was the best architect of any time. He prepared the first plan of Saint Peter without confusions, luminous and isolated not to interfere with any part of the Palace of the Popes. Anyone who had continued with his idea, as Sangallo did, starting off from the truth to surround it with a crown of darkness and, besides, eliminating the light from the rest, filling the whole space with corners for delinquency, so when closing it in the afternoons, more than twenty-five men were needed to vacate with a great effort the building of those who were hiding, can analyse it impartially. Sangallo’s project would need, because of that additional crown, the destruction the chapel of Saint Paul, the rooms of Piombo and many other parts, the Sixtine Chapel included. In addition, it would cost more than one hundred thousand crowns, since the remains and the existing foundations would not be of use. Thus I understand it and someone should convince the Pope of that, which is very difficult for me.” When in 1546 Michelangelo received the order to continue Sangallo’s work, his planning referred basically to the plan and to the inner illumination. He did not previously have an overall idea as Sangallo had. The previous year, Council of Trento did not make a clear statement about the shape of the temples, except for those of circular plan, which were advised against for being of pagans. His great skill in his first interventions was increasing its aspect of grandeur by diminishing its size (Fig. 6.42). By diminishing the plan, any possible type of dome would increase in elevation. He reinforced the central supports and made a model for the conclusion of the whole that was

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What was the contribution of Michelangelo to inspire such confidence? For a start, he had a clear and well dimensioned scheme. For the first time, an architect had made a categorical statement about a centralised plan (Fig. 6.43). There were no corners any more. Over a square there was a superimposed cross. The rest was masonry, and above it all, a drum and a dome that reflected Alberti’s spirit (Fig. 6.44). Also he was not Brunelleschi, he was a mix of Alberti and Bramante. A drum crowned by a hemispheric shell. But he also learned from that drawing that it was not enough. It had to be constructed, despite its 42 m diameter. In his drawings, Michelangelo tried desperately to lighten the loads, therefore the double sheet which would be hemispheric inward and slightly cambered outward to support the lantern (Fig. 6.45). And between them some meridian ribbings to connect them. There happened the paradoxical fact that the section is bigger in the key than in the base, unlike the Pantheon which model Bramante copied . To absorb the thrusts, he put a firm belt in the drum, very medieval like, but disguised as classical order (Fig. 6.46). Sixteen ribbings that corresponded to each one of the buttresses form the solid part of the dome. We will never know how Michelangelo’s scheme would have worked. He made sure that it was immutable by means of the construction of a wooden scale model (Fig. 6.47) which authority would maintain his presence after his death, in 1546. Only the drum did he see finished (Fig. 6.48). The responsibility of crowning it would be for others'. Nevertheless, his idea had an outstanding power since, despite the fact that he was in charge of the work for only fifteen of the almost one hundred and fifty years spent in the transformation of the paleochristian basilica and in spite of the over fifty architects who took part, the final project was his. Analysing his proposal, that some wanted to compare with Saint Mary of the Flowers, we find evident differences. The shape was not determined by the resistant behaviour, the constructive system, the state of the trades or by a structural challenge. The shape was an act of self-assertiveness of the ideas over the practice and of freedom over the rule. Argán emphasises this concept and the fact that the followers of the academical rules of Vignola found this behaviour repugnant. That is why his successors tried very hard to eliminate this stimulus to independence. Not being able to fight against the Master’s authority, they hid

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Fig. 6.49. Drawing by Dosio of the section and the lantern of the dome (Argan and Contardi).

Fig. 6.51. Section in perspective containing the drum, by Dosio (Argan and Contardi).

Fig. 6.50. Section in perspective of the dome, by Dosio (Argan and Contardi).

Fig. 6.52. Drawing made in Duperac’s atelier of Michelangelo’s idealised project (Argan and Contardi).

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the tests, lost his drawings and modified the scale model until Della Porta and Vanvitelli succeeded in making the others believe that their project was Michelangelo’s. That matter is discussed below. But, would the circular design have worked? The mathematical analysis cannot preview possible constructive solutions that could have made it viable. As a result of the autographed drawings (Fig. 6.45), there have been speculations on whether the outside shell was in “quinto acuto”, but the drawings by Duperac and Dosio’s sphere guarantee that, at least in its definitive version, he chose two hemispherical domes (Figs. 6.44 and 6.49). Fig. 6.50 , drawn from the original wooden model, supports this thesis. As for whether the inner ribs went along the whole meridian, the drawing of Fig. 6.51 clarifies it and, if they were interrupted at half their height in the later wooden model, it was due to the fact that Della Porta and Vanvitelli did not complete the lacking material when cambering the outside sheet. The image of Fig. 6.52, although infantile, made every doubt disappear and even set the concept of façade that Michelangelo had in mind, the model of which was lost. When he died in 1564, the work stopped. We have already seen how Piero Ligorio was dismissed without any consideration, for trying to change the drawings. The dome construction was not restarted until Della Porta, in 1588, decided to keep a modified project in use that he did not make clear was so. Lifting the outside dome almost eight metres, he approached the tracing in catenaries that could guarantee perfect stability. This implied that in the higher part, the inner ribs turned into excessively heavy real walls. The solution was diminishing their width while increasing the height. Fig. 6.53 shows a comparison between both projects. At the same time, some metallic rings were placed on the drum at a medium height, which must have hooped any tendency to radial opening. There are different opinions about the constructive system used. Some, such as Salman, claim that it was the same process as in Florence, which is doubtful since the geometrical planning was very different, whereas another, considering the amount of wood bought in 1589, deduce that it used a framework similar to that of Fig. 6.54, by Fontana. There are contemporary representations that go the same way. Fig. 6.55, also by Fontana, or Figs. 6.56, by Zabaglia, dating from 1773, copy graphics of the time. Mainstone justifies these aspects in detail. It is amazing that of such a singular work, made in a moment in which so many artists were transforming the city and drawing systematically its evolution, there is no drawing of the construction process. It is true that the construction only lasted three years and that, probably, during the process it must have been a mess of planks, protecting canopies and gross bricks. Even so, there is no justification for the lack of information that makes us work with hypotheses.

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Fig. 6.53. Comparison between Michelangelo’s dome project (left) and della Porta’s (right) (Mainstone).

Fig. 6.54. Framework proposed by Fontana for the dome construction (Mainstone).

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Using the same logic that we used on the dome of Florence, we think that the frameworks drawn by Fontana refers basically to the sixteen main ribs and that the rest could have been made with hardly a planking or hanging of a rope. Besides, two ribs could have been built at a time and afterwards the wood used for the other two (Fig. 6.54). The ribs, that had to be very deep in the key, could have been built less tall and increased later. That way, their weight would not rest totally on the framework during the construction. Fontana himself, in one of his descriptions, is rather explicit: “The tall walls grow like arches until the lantern base in sixteen ribs that close the space, having below and above the profile of the two layers, and they have keys to insert the stretches of shell until getting their complete shape. The sixteen ribs were first constructed and were not loaded until being properly hardened. Resting on them the circular sectors were made, having 1.38 m in the base and slightly diminishing toward the key with good bricks placed as a fish bone.”

Fig. 6.55. Drawing by Fontana (Zabaglia?) for the dome construction (Mainstone).

In no more than 21 months, in September of 1591, the work had reached the starting of the lantern. The mosaic ornament was initiated the following year and the mortar for recovering was used too to seal the fissures and cracks that appeared because of rheological effects. It seems unlikely that in that moment anyone attached a big importance to that phenomenon. Della Porta had succeeded in finishing, in a minimum term, a huge task about which others had been previously getting nowhere. He has the merit of the construction, though the design belongs, without doubt, to Michelangelo.

Fig. 6.56a and b. Section of the same scaffolding used for the furring, also in a drawing by Zabaglia (Mainstone).

But Saint Peter’s adventure had not yet finished. It seems that the existing cracks had increased in size causing alarm over risk of the collapse of the structure. Even Bernini was accused of being responsible, in part, for some slight modifications made in the supports. The 1730 earthquake forced the insertion of crack advance controllers. It was Vanvitelli in 1730 who did the first detailed report with graphics that signalled the position of the damage (Fig. 6.57). According to Mainstone’s analysis, all the cracks were initially due to the radial thrusts that, in addition, have separated the buttresses, besides the fact that the metallic rings did not work. We must not forget, though, that the structure is not laminar, but a set of sixteen powerful ribs with an edge of seven metres, linked by a skin much more fragile. Taking a good look at Fig. 6.57, every crack generated in the stretches agrees with that analysis. As for the buttresses, if they had opened they would have had cracks in the opposite way. It seems more probable that they were exhausted by the weak resistance to compression. Rondelet’s drawing (Fig. 6.58) reveals how little the buttresses section is. The cracks in the drum base show an insufficient bracing by the tubes of the naves. In any case, only an insufficient section of the base could be dangerous.

Fig. 6.57. Drawing by Vanvitelly with marks where the dome damage appeared (Mainstone).

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Fig. 6.58. Drawing by Rondelet explaining the damage and showing the weaker section of the drum.

Fig. 6.60. Analysis of the parabola of pressures, made by Poleni.

Fig. 6.61. Spatial analysis by Poleni, from which the breaking lines are obtained.

Fig. 6.59. Flat analysis of the dome behaviour by Le Seur, Jacquier and Boskovich and proposed reinforcements (Mainstone).

Fig. 6.62. Reinforcements proposed by Poleni.

What were the analysis and the dispositions of the contemporaries? In a report dating from 1742, Vanvitelli proposed the conventional solution of introducing four metallic rings for bracing, which did not satisfy the cultivated Benedict XIV who asked thee famous mathematicians to prepare a deeper report. Le Seur, Jacquier and Boskovich presented him their opinions that were published in a document of maximum scientific interest. Two alternative hypotheses, with and without the cracked buttresses, were based on it. In

both cases hinges were placed where cracks had effectively been found.

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Obviously, the analysis was flat, since there was still not enough knowledge to do a spatial calculation. In Fig. 6.59 can be seen the result of the visual check (central drawing), the consideration of the buttresses without cracking (above, left) and with the existing pseudovertical crack (above, right). In the first case, they deduced that there was a safety margin big

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enough even without working the chains placed during the construction. In the second case, the state was problematic even with the chains working. This second case was very pessimistic, since the cracking did exist. The proposed solution was a new chain, also shown. Nevertheless, that report must not have convinced the builders or the Pope, since it meant that the dome had to have already collapsed. A second report, by another great mathematician, John Poleni, has a greater importance because of its solid line of arguments. From the parabola of pressures of Fig. 6.60, he determined the point in which the hinge L must be produced, and set out a spatial analysis in Fig. 6.61. As a conclusion, he suggested the exact point in which should be placed the chain of hoops and even its value, though this had been rather arbitrarily deducted. Nonetheless, his line of arguments were speculative, since Vanvitelli already had taken care in placing the chains A, B, C, D and E in addition to the primitive ones n and u of Fig. 6.62. Saint Peter's sums up everything that happened in the XVIth century, though around it can be found great architectonic contributions. In short, we have seen how Alberti’s ideal is taken up by Bramante, who reinvents the ancient ideal, and is betrayed by Peruzzi, who favours Brunelleschi’s way, and above all by Sangallo, brilliant but tending to the Gothic in his development. When Michelangelo appears in the architectonic scene, he does it with his characteristic terribilitá, very few of his contemporary architects were able to escape his personal influence and almost none in the following century. Only one, greatest among the great, succeeded and saved the situation, keeping sane in the middle of insanity. Andrea Palladio reached the perfect architecture – at least, as defined by the later non-Italian architects. His complex works are such a prodigy of obvious simplicity. His religious architecture, from Saint Giorgio Maiore (Fig. 6.63) to the Divine Redeemer (Fig. 6. 64), is not a structural wonder, but it is a wonder in simplicity. It is in civil architecture where he expresses with more serenity the difficult balance between the complexity of the programmes and the clarity of the solution. Villa Rotonda is, maybe, the most successful house and the best known in history, surpassing Villa Savoie or the Cascade House, only to mention two of the most important (Fig. 6.65). From 1591 to 1624, there is little to tell about Italy. But we have overlooked what happened elsewhere, as in Spain, where Diego of Siloe, Hernán Ruiz and Andrés of Vandelvira made, in the XVIth century, basic contributions to architecture, even from a structural point of view. The decagonal dome of the Cathedral of Granada, by Siloe (Fig. 6.66), finished in 1557, the dome of the Real Chapel in Seville, by Hernán Ruiz (Fig. 6.67) and dating from 1562 or the group of vaults of so many Andalusian stonework churches that can be seen in Fig. 6.68, by Vandelvira. The solution a) is

Fig. 6.63. Saint Giorgio Maggiones, in Venice. Plans by Palladio (Wundram and Pape).

Fig. 6.64. The Divine Redeemer, in Venice. Plans by Palladio (Wundram and Pape).

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found in the Cathedral of Jaen that, otherwise, is a repertoire of almost every solution. The solution b) was frequently used by Juan Bautista of Toledo in El Escorial, or by Vandelvira himself in Saint Salvador in Ubeda. The solution c) is found too in Saint Juan Bautista in Chiclana. The d) solution that, as we can see, is a mixed one, is exquisitely represented in the treatise by Vandelvira, but is difficult to find at a considerable scale. The e) and f) solutions, with the ribs standing out, can be found in Our Lady of Consolación in Cazalla (Seville) or in Azpeitia (Guipuzcoa). In terms of importance, Juan de Herrera has not the value of invention of the others, though his participation in El Escorial gives him a certain pre-eminence. However, his Palladianism is ascetic and bare and his structural capacity remains dubious after his numerous constructive mistakes. In France, however, the Italian, Diaspora, brought big contributions. From Leonardo to Serlio, de L’Orme (Fig. 6.69) and Primaticio (Fig. 6.70), they are the best of the century. Fig. 6.66. Dome of the Cathedral of Granada, by Diego of Siloe.

Fig. 6.65. Villa Rotonda, in Vicenza. Plans by Palladio (Wundram and Pape).

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Fig. 6.67. Dome of the Real Chapel in Seville, by Hernán Ruiz (Escrig).

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Fig. 6.68. Solutions through stonework vaults made by Vandelvira (Cobreros).

Fig. 6.70. Primaticio’s project for the Chapel Valois, in St. Denis (Blunt).

The Italian Renaissance and its national branches still produced new models that we have to highlight if we intend to understand the Baroque. Serlio, in his Book V, developed the fundamentals of the elliptical plan tracing and several architectonical proposals (Fig. 6.71). His book, published in 1545, caused the construction of the little temple of Saint Andrea in Rome by Vignola, another great treatise writer and architect. It is one of those scarce examples of architectonical rotundity that summarises a whole programme in a little model measuring 10 x 7 x 2 m. (Fig. 6.72). In its second version in Saint Anne of the Grooms, a little bigger and with more ornaments, the modulation of orders is in direct conflict with the difficult geometry (Fig. 6.73).

Fig. 6.69. Chapel of the Castle of Anet, by Philibert de l’Orme (Blunt).

The work of Serlio and Vignola was better known outside of Italy than that of Michelangelo. Therefore, no wonder it turned out to be a pattern for the biggest constructions of this type. Whereas in Italy, Volterra, in 1590, plans the big dome of Saint Giacomo degli

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Fig. 6.71. Oval tracings by Serlio, from the books V and VII (Gentil).

Fig. 6.74. Saint Giacomo degli Incurabili, by Volterra (Lotz).

Fig. 6.72. Saint Andrea in Via Flaminia, in Rome, by Vignola (Escrig).

Fig. 6.75. Saint Mary in Vicoforte de Mondovi, by Ascanio Vitozzi (Lotz).

Incurabili, measuring 26 x 19 m (Fig. 6.74), Vitozzi begins a risky and troublesome construction in Saint Mary de Vicoforte in Mandovi, measuring 36 x 24 m (Fig. 6.75). It is in Spain, where some projects of this greatness are finished sooner. The Capitular Hall of the Cathedral of Seville, begun in 1569 by Hernan Ruiz (Fig. 6.76) and the Cathedral of Cordoba transept, with the same plan but started in 1557 (Fig. 6.77), are the forerunner masterpieces of elliptical plans. Fig. 6.73. Saint Anne di Palafreneri, in Rome, by Vignola (Escrig).

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Alonso of Vandelvira’s treatise, dating from around 1590, explains a good systematisation of the

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Fig. 6.76. Capitular Hall of the Cathedral of Seville, by Hernán Ruiz (Gentil).

Fig. 6.77. Dome of the Cathedral of Cordoba, by Hernán Ruiz (Gentil).

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Fig. 6.78. Elliptical domes tracings by Andrés de Vandelvira (Cobreros).

Fig. 6.79. Drawing from the Treatise of Vandelvira, showing the final solution of Fig. 6.78 (Palacios).

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a) STRESSES DUE TO SELF WEIGHT b) GEOMETRY FOF THE MODEL

DEFORMED SHAPE DUE TO SELF WEIGHT Fig. 6.80. Efforts developed in the elliptical dome of the Capitular Hall of the Cathedral of Seville (Cobreros).

stonework quartering for this sort of work. Fig. 6.78 shows the three basic patterns that correspond to the name of the treatise and Fig. 6.79 is an example of the rigor with which he set out the stonework construction of this new structure, being followed by the rest of the Spanish architects mentioned. Hernan Ruiz´s work can be of use, since it has been well studied, to illustrate the structural behaviour of these shapes (Fig. 6.80). In the mathematical model we can see how logical the efforts in each meridian are but are not constant in each parallel. We know that, in practice, these domes are very flat in the base and undergo much flexion and cracking in their lower

part. The maximum momentums are developed in the short axis, as we will see below in Vicoforte. In the model, the low parallels stand out in traction and the shifting matches with a great precision that found by photogrammetrical methods (Fig. 6.81). Saint Mary of Vicoforte has been studied more since, due to differential settings, it has had to be reinforced recently (Fig. 6.82), and the conclusions are rather similar: strong tractions in the base parallels, bigger in the short axis, and large deformations of the meridian in the long sides. Finally the repairs, independent of the foundation reinforcement, consisted of a ring hoop that, being elliptical, had to be applied by sections and with a variable prestressing.

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Fig. 6.82. Phogrammetrical analysis and pathology of Saint Mary in Vicoforte de Mondovi, before its restoration (Pizzeti and Fea).

Fig. 6.81. Photogrammetrical analysis of the dome of the Capitular Hall in Seville (Gentil).

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REFERENCES OF CHAPTER 6

1. ARGAN, G.C. & CONTARDI, B. “Miguel Angel Arquiteto”. Electa, Milan. 2. BLUND, A. “Arte y Arquitectura en Francia 15001700”. Ed. Catedra. 3. BRUSCHI “Bramante”. Laterza, Bari. 4. COBREROS, M. & VAZQUEZ, E. “The sail vault: A survey of constructive techniques to stalilize a sophisticated structure”. STREMA. WIT Press, Southampton. 5. CREVE, S. “Visionary Spires”. Waterstore, London. 6. ESCRIG, F. “Tecnología en los Edificios Históricos”. STAR nº 2. ETSA, Sevilla. 7. ESCRIG, F. “Towers and Domes”. WIT Press, Southampton. 8. FIORE, F.P. & TAFURI, M. “”Francisco di Giorgio Architetto”. Electa, Milano. 9. FURNARI, M. “Atlante del Renacimiento”. Electa, Milan. 10.GENTIL, J.M. “La traza Oval y la Sala Capitular de la Catedral de Sevilla”. ETSA Sevilla. 11. HEYDENREICH, L. & LOTZ, W. “Arquitectura en Italia 1400-1600”. Catedra, Madrid.

12.KRAUS, F. “Bramante's Design for the Dome of St. Peters Cathedral in Rome. A study using experimental stress analysis techniques”. STREMA. WIT Press, Southampton. 13.LOTZ, W. “Architecture in Italy” Yale Univ Press. 14.MAISTONE, R. “Structure in Architecture: History, Design and Innovation”. Ashgate Publishing Ltd., U.K. 15.MILLON, H.A. & MAGNANO,V. ”The Renaissance: From Brunelleschi to Michelangelo. The representation of Architecture”. Thames and Hudson. 16.MURRAY, P. ”La arquitectura del Renacimiento Italiano”. Aguilar, Madrid. 17.PALACIOS, J. C. “Trazas y Cortes de Cantería en el Renacimiento Español”. Ministerio de Cultura. 18.PALACIOS, J.C. “La cantería en la construcción del Renacimiento Andaluz”. Consejería de Cultura de Andalucía. 19.PORTOGUESI, “Roma del Rinascimento”. Electa, Milan. 20.TAFURI, M. “Ricerca del Rinascimento. Principi, città, architetti”. Einaudi,Torino. 21.TAFURI, M. “Rafaello Architetto”. Electa, Milano. 22.TESSARI, C. “Baldasare Peruzzi”. Electa, Milano.

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Chapter 7. THE OMNIPRESENT SINAN

We have already explored how the Renaissance was not a phenomenon limited to the western world. Together with an economic and political flowering there were similar manifestations in several regions of the civilized world. From our perspective of being at the centre of the universe, the mosques of Istanbul, the Taj Mahal, the Forbidden City in Peking or the Lama Palace in Tibet seem to us wonderful curiosities. Now we are going to see, very summarily, what happened in Turkey, India and some other regions, but we do not deny the universality of the phenomenon. Ottoman Turkey was born in the XIVth century, when conquerors descended from the mountains to put an end to the Eastern Empire. In 1453, Bayaceto II took Constantinople after having controlled the surroundings for one hundred and fifty years. Their great merit, that

Fig. 7.1a Mosque of Sefereli (Goodwin and Stierlin).

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The Serefelli Cami (Mosque of Serefelli), dating from 1440, is the first model produced by the great new architecture. Its only dome, 24 m in diameter, is of gigantic dimensions. It is still clumsy in its resolution as well as dark and spatially squat (Fig. 7.1a), but it partially reminds us of the Pantheon. The Fig 7.1b shows the finite element model with stresses due to its own weight. The Complex of Fatih overcomes this problem by introducing a drum with openings for illumination. Finished in 1488, the engraving by Lorish shows its former aspect, since the present building is the result of a reconstruction (Fig. 7.2). It was 26 m in diameter. The architect Hayreddin appears as the master forerunner of the new Islamic spaces. Fig. 7.1b Finite Element Analysis of the Sefereli Mosque (Escrig).

allowed a stability lasting until the First World War, was to found an infrastructure system that bound the whole territory and gave power to the cities. In that system were included all the public buildings such as mosques, madrasas, caravasars and palaces, that made of architecture a political and administrative activity. Obviously, the Seljukians knew well the Byzantine and Persian constructive traditions and were able to mix with their own models the brilliant features from Byzance and Isfahan.

The Complex of Bayaceto in Edirne, has a mosque with an unitary space that is reminiscent of the best Florentine creations (Fig. 7.3). It is in the Mosque of Bayaceto in Istanbul, by the same architect, where the total recovering of a space similar to that of the Church of Saint Sophia (Fig. 7.4a) takes place. Its plan is identical and has the same counteracting system, though at a scale one half (Fig. 7.4b). In the drawing by Lorish it rises majestically on one of the hills (Fig. 7.5).

Fig. 7.2. Complex of Fatih, in an engraving by Lorish (Goodwin).

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Fig. 7.4. Complex of Bayaceto in Istanbul (Escrig).

Fig. 7.3. Complex of Bayaceto, in Edirne (Stierlin).

Despite this acknowledgement of the superiority of Justinian’s architecture, when the successor of Bayaceto, Selim I, must face the disasters of the 1509 earthquake, his big mosque resorts again to the unitary space, which best guaranteed the counteracting of thrusts (Figs. 7.6), since it has the same dimensions as the Mosque of Fatih. This official architecture was going to be reproduced all over the huge territory with the same patterns, in the way that the Roman

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architecture did with its own. We do not know why, Hayreddin decided not to keep on experimenting after his first successes. But he had opened a door that, during the period of Soliman the Magnificent, would gather the decorative and the utilitarian arts. We must refer to the fact that in Florence there was also a great prince of the arts who was magnificent and that Leonardo himself, wandering from court to court, thought of offering the caliph his services. A military engineer who was going to revolutionize architecture, Mimar Sinan, educated in the army, was head of the military engineers and appointed Head of Architects when fifty years old and is the best known of the eastern architects. He started off from the lower ranks of the army until being appointed Head of Engineers in 1536. This allowed him to visit many places, gathering much data and, more important, setting a centralised cabinet that had to export

The Omnipresent Sinan

Fig. 7.5. Complex of Bayaceto in Istanbul, by Lorish (Goodwin).

Fig. 7.6. Mosque of Selim I (Goodwin).

Fig. 7.7. Mosque of Sehzade in Istanbul (Goodwin).

solutions for the constructive problems of the whole Empire. His first great work was the Mosque of Sehzade in Istanbul (Fig. 7.7). He recovered with it the ideal of a centralised plan in a Greek cross, building a high central dome equally balanced with caps in all four sides and, at the same time, counteracting these caps by means of other smaller ones (Fig. 7.8a). The dome would therefore have four perfectly supported transverse arches, that would allow putting holes all over the walls. Four short but massive towers, acting as a counterweight, would stabilise the diagonal thrusts, for their part (Fig. 7.8b). The inner space has a level hierarchy that Brunelleschi had established, though in his own way, including the planking, the cornice, the transverse arches with the spherical

Fig. 7.8.a. Interior of the Mosque of Sehzade (Stierlin).

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Fig. 7.8d. Seismic behaviour of the dome of Sehzade by Finite Elements, according to Crocci (Escrig).

Fig. 7.8b. Sections in height of the Mosque of Sehzade (VogtGöknil and Güngör).

Fig. 7.8e. Displacements and thrusts of the main arches by Finite Elements (Karesmen).

Fig. 7.8c. Discretisation of the dome of Sehzade by Finite Elements (Escrig).

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Fig. 7.8f. Reactions in the supports, due to their own weight and to the seismic actions (Karesmen).

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pendentives, the drum and the dome. There is so much luminosity that none of these mosques was planned to break with an oculo or a lantern, the perfection of the half-sphere. This work, though innovative in respect of the space unity, follows the constructive techniques in vogue that proved so effective. First, the drum, that on the outside looks like such, but inside forms part of the same shell, so that the openings in it act as supports on which rests a flattened hemispheric dome. The angle of the arch of complete circle rarely surpasses 120º and it means, in accordance with the shell theory, that there could be obtained only small tractions for snow loads. For its own weight they are fully in compression. Nevertheless, an edging ring is always skirting around them. Their thickness is around 60 cm, which makes them very light, and are formed by a single layer, thus avoiding the orthotropism of the rib domes that had caused so many troubles in Florence and Rome. The scaffolding may rest on the cornice of the drum base and be outstandingly light since it hardly has any weight to resist, and even less when the bricks are placed in completing rings. This scaffolding will be that used for the positioning of the ceramic decorative elements. The lightness results too in the occupation of the resistant elements in plan. Compare the relation between the useful surface and the constructed surface with the large western Renaissance structures to see

the point of economy reached. Sinan always considered this construction his masterpiece. Its 19 m dome is not spectacular for the dimensions but for the harmony of its shape (Fig. 78c). Karaesmen, who has intensely studied the behaviour of these structures, deduces that the maximum compression is 3 Kp/cm2 in the key and that the tensions in the meridians are very uniform, around 1.3 Kp/cm2. The flexions are insignificant because of having a behaviour very similar to that of a membrane (Fig. 7.8e). On the other hand, the 24 supports of the dome on the drum have an important role in the seismic behaviour, since they absorb much of its energy. This way, it happens that those resting on the transverse arches do more work than those resting on the pendentives, due to the flexibility of these. The maximum cutting effort in these supports is 3 Kp/cm2, very high and close to its limit. Therefore, one of the most complex aspects of these domes is their dimensioning. The analysis of these domes by finite elements has obtained movements as those shown in Fig. 7.8d. This shows the displacements and thrusts obtained for their own weight, and Fig.7.8f the reactions from their own weight and to earthquakes. To balance the thrusts better, the secondary arches are provided with iron struts that absorb 28% of the seismic effort. As for the small counteracting domes, they play a main role in the seismic behaviour, since they absorb

Fig. 7.9a. Mosque of Suleiman.

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Fig. 7.9b. Mosque of Suleiman. Horizontal sections (Goodwin, Vogt-Göknil and Güngör).

17%. Perhaps all this explains the great stability of these works in such an unstable situation in case of earthquakes. In order to finish with this analysis, it must be said that the four large inner supports are apparently over dimensioned, working to 38 Kp/cm2, a measure that we must accept with reservations for being excessive, although this includes the flexion efforts.

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The work was finished in 1548. Meanwhile, Sinan had already begun the construction of the second of his great works, the Mosque of Suleiman, much closer in its solution to the Church of Saint Sophia (Fig. 7.9). Its dome rises to 54 m of height, being 24.5 m in diameter and having a cap 8.6 m high. Its thickness goes from 0.4 m in the key to 0.8 m in the base. Figs. 7.10 and 7.11 testify to the similarity between the two

The Omnipresent Sinan

Fig. 7.10. Inner view of the Mosque of Suleiman in two perpendicular ways (Stierlin).

Fig. 7.11. Inner view of the Mosque of Saint Sophia in the same ways (Stierlin).

churches, comparing them from the same point of view. The only difference is that, in this case, the transverse arches are pointed. It is worth the trouble to detail the constructive systems and the characteristics of the materials, to analyse the behaviour of this structure. Although stone is used abundantly in the walls and supports, the domes are made of bricks stuck together with a mortar made up of brick dust mixed with lime oxide that has a good setting capacity. Its density is 1.8 Ton/cm3and its average resistance to compression is 40 Kp/cm2 and to traction is practically non existent. It seems that Suleiman’s decision of linking its architecture to the Byzantine one had to do with his will to recover the Eastern Empire at its time of greatest splendour. For that reason, he did not follow the path opened by Sinan with its amazing Sehzade Cami, which he would surpass in later works. The construction took place between 1550 and 1557. This period matches with that in which Michelangelo was developing the definitive version of his Great Dome in the former capital of the other Empire. The counteracting system of Saint Sophia, which he repeated in the Mosque of Suleiman, was completely

called into question in a later work of extreme simplicity. The Mosque of Mihrimah in Edirne, finished in 1560, rises plumb vertical on vertical plans that seem to defy the laws of thrusts (Fig. 7.12). Its domed plan is a perfect square with walls pierced by the light in all their extension (Fig. 7.13). Its dimensions, relatively reduced, are balanced by a greatness that gives it the coherence of design. In this case the dome is 20 m in diameter, rising up to 37 m of height (Fig. 7.14). Although the total plan is rectangular, in Fig. 7.15 it can be seen how for more than two thirds of its height it rises on a square formed by fragile walls. The weight of 890 tonnes of this dome, triggers some reactions that are expressed in Fig. 7.16, where the earthquakes have been considered as 15% of the vertical loads. The supports, due to the combined actions, work under 42 Kp/cm2 according to Karaesmen and without considering the rigidity of the closings that are otherwise small. Surely the most impressive structure, because of its unity and its structural firmness, is the mosque of Selimiye, finished in 1574. It surpasses in dimensions Saint Sophia since it is more than 31.5 m in diameter and 44 m high (Fig. 7.17). The regularity of its shape, the perfection of its structural system, the resources

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Fig. 7.14. Axonometric sectionning of Mihrimah (Freelhy and Burelli).

Fig. 7.12. Mosque of Mihrimah in Edirne (Kuran and Stierlin).

optimisation and the beauty of its decoration are but some of the many arguments to name it the most outstanding work of Ottoman art (Fig. 7.18). In Fig. 7.19 can be seen the setting of the dome on eight transverse arches and its alternate rate of a flat stretch and a curved stretch. Fig. 7.20 shows the decreasing system of the masses expressed by means of a successive reduction in height. We can see that the eight powerful buttresses finish and become hardly visible from the outside, and instead are continued by eight massive towers that give the whole a characteristic aspect. Fig. 7.21 explains its structural and seismic behaviour. As we have seen in a few examples of Sinan’s greater works, his patterns always consider a rectangular plan, square in some rare cases, paradoxically ending sometimes with domes on an octagonal or hexagonal base. Fig. 7.22 shows the main projects, as well as their dimensions and their supporting system.

Fig. 7.13. Plan and vertical section of the Mosque of Mihrimah in Edirne (Vogt-Göknil).

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Since we have pointed out the coincidences with western architecture of the time, it is worth noting the existence of the mausoleums of circular or polygonal plan, imitating the shrines and recovering the paleochristian baptisteries and tombs. In Fig. 7.23 we can see that of Suleiman and in Fig. 7.24 that of Selim. In both of them a narthex or access is included and they have only domed space. They would dignify by

The Omnipresent Sinan

Fig. 7.15. Horizontal sections of the Mosque of Mihrimah, in Edirne (Güngör).

Fig. 7.16. Reactions in the base of the arches, due to the gravitatory loads and the seismic action in Mihrimah (Karesmen).

themselves the Eastern architecture, had the gigantic constructions that we have described not existed. In so brief an account, we cannot expand more on the panorama of the classic recovery, of which we have a serious lack of documentary information. Fig. 7.26 shows one of the few architectonic representations that have been conserved. It is the Mosque of Suleiman scale model, ordered by Murat III as late as 1582. In any case, it is surprising that the representation of human figures was a characteristic feature of the whole empire, considering the strict Koranic prohibition.

Most probably, the almost five hundred documented works by Sinan were not possible under his exclusive design and direction. The Sultan’s head architect must have been in charge of a centralised cabinet that would supply the whole empire, and its directives must have had a graphical format, as happens in any culture. A subject for discussion would consist of finding out whether any sort of verbal or literary instructions existed, that could become an object and the degree of freedom of master builders and masons. It is possible that the scale model replaced advantageously the plans, since the lack of knowledge about the flat projection systems and the use of perspective must have been compensated with three-dimensional figures. It is inconceivable that in a system of cultural transmission as permeable as this one that allowed for the West being aware of the Islamic works, there would not develop the inverse phenomenon. When Bayaceto asked Gentille Bellini to paint his portrait in the Palace of Topkapi, this last met with Patriarch Gennadios Scholarios to explain to him some concepts of the Italian art. In fact, Maquiavelo defended Bayaceto as a true Renaissance prince. For his part, Bayaceto asked Leonardo and Michelangelo to project the building of a bridge on the Gold Horn (Fig. 7.27). Tiziano himself painted two pictures of Suleiman, which is paradoxical for the official painter of the biggest Ottoman Empire enemy, the Emperor Carlos V. There is a copious bibliography on our architect that offers numerous biographical data, describing the characteristics and the number of his works but failing in depth on the graphical, cultural and constructive concepts. We know that Saint Sophia was constructed in five years, the Mosque of Suleiman in seven and that of Selimiye in six. In contrast, the

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Fig. 7.17. Plan and vertical section of the Mosque of Selimiye (Vogt-Göknil).

Fig. 7.18. Outer aspect of the Mosque of Selimiye (Stierlin).

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Fig. 7.19. Inner aspect of the Mosque of Selimiye (Stierlin).

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Fig. 7.21b. Thrusts (Kp/cm2) obtained for the Mosque of Selimiye (Sánchez, not published).

Fig. 7.20. Horizontal sections of the Mosque of Selimiyem in Edirne (Güngör).

Fig. 7.21c. Deformations (in black) over the initial geometry (in grey) of the Mosque of Selimiye (Sánchez, not published).

building of Saint Peter took 160 years, from Twine to Bernini, and Saint Paul in London, forty. This alone proves the huge capacity of organisation of the work processes in the eastern art. After Sinan, great constructions were built on which we will not expand because they no longer brought innovations and because they get out of our temporary frame. The Ottoman art of the XVIIth century lost all its vitality and was not able to be revitalised, contrary to what happened with western art. Basically, the religious tensions between the Sunnis and Shiites were an unbearable burden in which the intransigence and dogmatism ended up winning. Fig. 7.21a. Mosque of Selimiye in Edirne, through discretisation by Finite Elements (Sánchez, not published).

The unity and the communication provided by the Islamic religion facilitated the fact that in very distant

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Fig. 7.21c Mode 9 of vibration obtained for the Mosque of Selimiye (Escrig).

Fig. 7.22. Plans of some works by Sinan (Güngör)

Fig. 7.23. Mausoleum of Suleiman (Tanieli).

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Fig. 7.24. Mausoleum of Selim (Tanieli).

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Fig. 7.25. Plans of some mausoleums. The first two are are of Suleiman and Selim I (Tanieli).

Fig. 7.26. Drawing of the Mosque of Suleiman scale model, ordered by Murat in 1582 (Kuran).

parts of the world architectonic developments of large dimensions simultaneously took place. The pilgrimage to Mecca and the fact that the Jesuits began an evangelisation campaign all over Asia explain certain manifestations that, otherwise, would be difficult to understand. In India, under the Mogul empire, works as beautiful and coherent as those of the best Italian Renaissance were constructed. It is in the mausoleums where the domed spaces acquire a personal meaning, since

these huge elements are not used for worship. In this sense, we are going to point out only three important works. The tomb of Humayun (Fig. 7.28), dating from 1560, could have been a beautiful palace had it not been a burial monument. In this work, as in other later ones, the architecture is complemented by gardens, fountains and by the water. It is not a structure of great dimensions but is very subtle indeed. The Taj Mahal (Fig. 7.29), with its bulbous domes and its white marble

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Fig. 7.28. Tomb of Humayun (Stierlin).

Fig. 7.27. Drawing of a bridge for the Gold Horn in Istanbul, by Leonardo.

stonework, has a peculiar section, otherwise habitual in these domes. The inner flat dome takes control of its thrusts by means of the weight of thick ashlars in the outer dome (Fig. 7.30). In this case, it is more amazing for the geometric richness than the structural dimension. The centralised plan is reminiscent of the bubbles proposal by Leonardo. In this case, the system does not change. A square is divided into nine square parts. The interior practically keeps its dimension to be covered with the great dome that to the outside emerges taller than the towers. The four corners absorb the thickness of the walls, each one supporting a small dome. The other four lateral squares become triumphal arches, named ivans, which frame the accesses. The passage from a square plan to the circular one of the domes is solved by means of a fractal fragmentation of the ascending parallels and complex geometrical ornaments instead of the Renaissance pendentives, the Romanic trumpet shells or the Islamic faience stalactites (Fig. 7.31). This avoids the existence of the transverse arches that gave their supremacy to Italian architecture. These systems, in which the mass rises over the void, guarantee their own survival in times of neglect or looting. The third Hindu work of interest to us is the tomb of Goal Gumbaz in Bijapur, a small stylistically subtle work but structurally, maybe the most ambitious work of all (Fig. 7.32). Bijapur is in the south of India and represents the last period of the mogul conquest against sultan Muhammad, who ordered the construction the building to be eclectic and different from the prevailing architecture.

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Fig. 7.29. Taj Mahal (Stierlin).

It must have been a task more impressive than the construction of the three great Italian domes. It is not placed within a basilica, does not have superfluous elements that make it smaller and does not add any special constructive ability. It is simply a cube on which has been put a hat (Fig. 7.33). The dome is a perfect semicircle, with a constant thickness of three metres. The only bracings are the towers in the corners, since the rest of it is a long wall of 50 m of length and 4 m of thickness, as flat as a floor tile, on which rests a dome with transverse thrusts of one thousand tonnes.

The Omnipresent Sinan

Fig. 7.32. Tomb of Gol Gumbaz, in Bijapur (Stierlin).

Fig. 7.30. Section of the Taj Mahal (Stierlin).

Fig. 7.33. Axonometric sectionning of the Tomb of Gol Gumbaz (Stierlin).

Fig. 7.31. Passage from a square to a circular plan (Stierlin).

Nonetheless, the bare interior gives the feeling of belonging to another world. It is an immense space of 1700 m2, wider than that of any Italian dome. In this case it has two levels, one with a vaulting fan in a style close to the Gothic, and the superior in hemisphere completely smooth and bare, that seems to belong to another building due to a corridor three metres wide interposed between both levels (Fig. 7.34).

How was it constructed? How has it lasted so long without deformations? As we do not have further information, we will not deliberate on this matter. The fact is that this work, dating from between 1626 and 1656, is something too singular and simple within the Eastern culture. Until the arrival of concrete, a construction of this magnitude was not undertaken. We contribute, therefore, to this text our own analysis by finite elements of a possible behaviour of the tied ashlar stonework of this complex device (Fig. 7.35).

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Fig. 7.34. Gallery in the dome spring of Gol Gumbaz (Stierlin).

Fig. 7.35. Discretisation by Finite Elements of Gol Gumbaz (Compán, not published).

Fig. 7.36. Discretisation by Finite Elements of Gol Gumbaz (Compán, not published).

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REFERENCES OF CHAPTER 7

1. BANISTER FLETCHER “A History of Architecture”. Butterworths, London. 2. GOODWIN “A History of Ottoman Architecture”. Thames and Hudson, London. 3. GÜLER, A. “Sinan: architecte de Soliman”. Arthaut, París. 4. KAMESMEN, E. “A study of the Sinan's Domed Structures”. Computational Mechanics

Publications, Southampton. 5. KURAN, A. “Sinan: el maestro de la arquitectura otomana”. Ed. Universidad de Granada. 6. STIERLIN, H. “Turquía. De los Selyucidas a los Otomanos”. Taschen, Colonia. 7. TANYELI, G. “Structural use of Iron in Ottoman Architecture (From the 15th to the early 19th)”. Computational Mechanics Pub, Southampton.

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Chapter 8. EVEN FURTHER

The Ming culture, developed in China between the XVth and the XVIIth centuries, although being a continuation of a thousand-year-old tradition and a compendium of gigantic buildings that, as in India, cannot be separated from the landscape, has an amazing constructive quality in marble and wood. But we must remember that this style does not have any link with the Roman tradition nor the Islamic one. None of these cultures arrived in China before the XVIth century.

extremely baroque. The correlation between them is similar to that between the Romanesque and the Gothic, increasing in the Yünng dynasty (1279-1368). For that reason, what happened during the Ming dynasty (1368-1644) can be clearly expressed as a contemporary Renaissance, complementary to those mentioned in the preceding chapters and with a value still not acknowledged to the present. They share the same characteristics:

Peking by itself is a compendium of very diverse styles, although to western eyes they may look very similar. As Bussal says, the Ming style is different to the previous ones, the Tang (581-907) and the Sung (9601279). The first one is very sober, and the second one

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Rigid axial symmetry. Strong plinths supporting a simple wall structure with special features for each work. A subtle cover raised with its cresting and certain

Fig. 8.1. Relief representing a palace from the Han Dinasty (Metropolitan Museum of New York).

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Even Further

Fig. 8.2. Relief from the Tang Dinasty (Bussagli).

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monotony, mainly in public buildings of importance. There is also an only religion, Buddhism, that gives an ideological content to whatever is done. The buildings are settled in urban environments almost as important as them and designed as the architecture itself: the net of axes and streets, the elements of artificial landscapes, lakes and hills are proof of an elaborated theory reached with consensus.

The basic style of the construction consists of a strong plinth of stone or bricks, smooth or forming terraces, where a great part of the descriptive ornamentation is placed–dragoons, lions, plumes, wheels–including words with initiation information to understand the building. The façade level is usually columned, with simple or multiple corbels that allow making a good use of the existing wooden squares and covering wide spans by means of that particular lintelled system. Finally, a cover of a great spread is superimposed, having one or many levels with its characteristic curved edges that unequivocally show the magnitude of the building. Perhaps the repetition of this system, of which old plans have been conserved, supports the western thesis that the Chinese architecture is no more than a

slow evolution. A relief conserved in the Metropolitan Museum of New York (Fig. 8.1), dating from the Has dynasty, contemporary of the Roman Republic and Empire, describes this system perfectly. An engraving from the Tang dynasty, abounds in this description (Fig. 8.2). A drawing of a fortification, from the same dynasty, even uses colours (Fig. 8.3). At last, a plan from the Sunj dynasty, signed by the official Li Chieh in the XIIth century, as well as innumerable other drawings, give abundant information about the slightest changes in style (Fig. 8.4). So that, any of the plans of the Ming period made by Stielin can seem familiar (Fig. 8.5). My own sketches from life, drawn in the Forbidden City, reveal this evident complexity (Figs. 8.6, 8.7 and 8.8). The best thing that we can say about the structure of the system is that the great spans of the cover are solved with impossible squares, since they work almost exclusively under their own weight. In Fig. 8.9 the beam corbelling system can be seen with more detail. We must not think only about the construction. In civil engineering this architectonic system also opened possibilities as in the Bridge of Liling in Hunan (Fig. 8.10), where the span of the sections were shortened by means of a successive advance of the beams. The short squares also would be used for big arched spans, like the solution represented in Fig. 8.11 for the bridge of Kainfeng, curiously the same scheme was used by Leonardo three hundred years

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Fig. 8.4. Plan drawn by Li Chie during the Sunj Dinasty (Bussagli).

Fig. 8.3. Drawing of a fortification in the Big Wall from the Tang Dinasty (Jeannel and Koryrepf).

Fig. 8.6. Shrine in the Forbidden City (Escrig).

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Fig. 8.5. Present constructive elevation plan (Stierlin).

Even Further

Fig. 8.7. Detail of the previous shrine (Escrig).

Fig. 8.8. Detail of the eave of the previous shrine (Escrig).

Fig. 8.9. Corbelling system of the cover beams (Pirazzoli).

Fig. 8.10. Bridge of Liling in Hunan (Pirazzoli).

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Fig. 8.11. Bridge of Kainfeng in a picture from the Song period (Pirazzoli).

Fig. 8.12. Drawing by Leonardo for a bridge built with short squares.

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Fig. 8.13. Prayers Room in the Temple of the Sky in Peking (Escrig).

Even Further

Fig. 8.14. General plan of the Forbidden City (Jeannel and Kozyrepf).

Fig. 8.15. General view of the Forbidden City, from the Coal Hills (Escrig).

later in numerous drawings, as he must have considered it an extremely important discovery (Fig. 8.12). The Prayers Room in the Temple of the Sky in Peking (Fig. 8.13) or the Forbidden City complex (Figs. 8.14 and 8.15), illustrate this sufficiently.

A greater explanation is required for the towers that, like in the European Renaissance, undergo their fading or a loss of quality during the Ming dynasty. It is paradoxical that the high elements even lose their symbolic value in the classic periods. For that reason, the most famous Chinese pagodas were built before the Ming period.

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We are not going to speak here about the excessively ornate and imaginative sculptural architecture of Southeast Asia, including Hindu India, no matter how much plastic value it has. Its landmarks were ancient and extinguished from year 1000. Therefore, we understand that those decorated accumulations were seen as archaeology from the XVth to the XVIIth centuries. Japan is the only country that, always with a minimum geographic space, delimited along history: that existing today, devoid of the continental part, gathered some particular features of interest. However, this interest is based fundamentally on the fact that they have penetrated contemporary architecture to the marrow. Wright or Neutra made a religion out of its simplicity, that is kept alive in some great contemporary architects like Tange, Ando, Isozaki or Ito. The Japanese developed their practice from their continental architecture. The network of temples of the Heian period (794-1185) gave rise to a massive transference of Chinese technology and design that would be evident in very similar buildings with a certain baroque style. Nonetheless, the attempts of the emperor to get rid of the interferences of the Buddhist clergy that arrived with the architecture, led to a personalisation of the style.

Fig. 8.16. Pagoda Yahushi-ji in Naran (Heinle-Leonhardt).

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The Yahushi-ji Pagoda in Naran (around 700) is an example of the special structural complexity of using little wooden squares. The central mast, without a structural function, must have belonged to the sturdiest tree of the forest (Fig. 8.16). We find here a great ecological respect that is reflected in the fact that Japan has kept its vegetation, whereas in China the big reconstructions of the XIXth century were made with wood imported from the United States. However, we are speaking of a remote time. In the XVIth century, the introduction of firearms, the arrival of western civilization and the strong military boost by the dominant class, developed a kind of picturesque castle of which Himeji is like a new city of Urbino (Fig. 8.17). Constructed in 1580, it is an example that did not go further. In fact, the islands do not need castles but coastal artillery batteries and a defence fleet. For that reason, rules were immediately promulgated to lower the profile of the cities to a maximum of 31 m and modules of construction based on the tatami (918 x 1837 cm2) were established. In accordance with this and to make good use of the residential surface, there was a tendency toward an organic plan in which the structure did not condition the construction. For that reason, the ceiling frameworks had to manage to adapt to irregular plans in search of the only place to rest on, the contour. In addition, this must have been done with small wooden sections. This is the great merit of Japanese architecture: not the Chinese or the western greatness but the extreme subtlety, a subtlety represented by the paper walls, the complete lack of furniture and gardens empty like deserts. Fig. 8.18

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Fig. 8.17. Castle of Himeji, in Japan (Jeannel and Kozyrepf).

shows the Castle of Nijo, from 1602, whose image does not match with that of a castle. In the remotest place in the world, in an unknown continent that without doubt had been permeable to Asia through the Pacific, cultures of the highest level thrived. We cannot link this phenomenon to the global phenomenon of the Renaissance because of the lack of communication between that world and the western and eastern civilized worlds. For that reason, the Inca or the Mayan culture, despite their representing stellar moments for architecture even from the point of view of their structural richness, are not to be considered in this section. Nevertheless, when Hernán Cortés entered Tenochtitlan, a recent people like the Aztec were developing a new architectonic refinement that fascinated the conquerors, amazed by wide spaces of the layout of the American Venice (Figs. 8.24 and 8.25).

Fig. 8.18. Castle of Nijo (Stierlin).

Though it might seem that these are piling systems similar to those in Mesopotamia, the reality is more complex, with a superposition of levels that included large closed spaces (Fig. 8.26).

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Fig. 8.19. Structural plan and mathematical model for the calculation of a pagoda (Hanazato).

(after Inayama 1995)

Fig. 8.20. Unlinear diagram of the restituted rotational coefficient and semi-rigid model of knot with a beam going through (Hanazato).

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Qy: Ultimate Strength of Dowel K: Stiffness by Embedding of Dowel into Block and Shear Deformation of Dowel Fig. 8.21. Model combining a dowel and a support for the studwork complex (Hanazato).

Translational Spring

s: Translational Displacement due to Embedment of Dowel into Block and Deformation of Block è: Rotational Angle due to Column Rocking Resistance

Rotational Spring

Fig. 8.22. Model of the behaviour of the arms knot system (Hanazato).

Fig. 8.23. Seismic and wind behaviour of the tower in its different storeys (Hanazato).

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Fig. 8.24. Reconstruction of the lacustrine city of Tenochtitlan (Gendrop-Heiden).

Fig. 8.25. Religious zone of the city of Tenochtitlan (Gendrop-Heiden).

Fig. 8.26. Building piercing of the great pyramid of Tenochtitlan (Lavallée-Michelet).

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REFERENCES OF CHAPTER 8

1. BUSAGLI, M. “Arquitectura Oriental”. 2 Tomos. Ed. Aguilar, Madrid. 2. FLON-GRANVAND, CHR. “América Precolombina y Colonial”. Salvat Ed. 3. GENDROP, P. & HEYDEN, D. “Arquitectura Pre colombina”. Ed. Aguilar. 4. HAWKES, N. “El genio del hombre”. Debate, Cir culo de Lectores. 5. HEINL,H. & LEONHART, F. “Tours du Mond Entiere“. Livre Total, Lausane.

6. HEINL, H. & SCHLAICH, J. “Kuppeln aller Zeitenaller Kulturen". Deutsche Verlags- Anstalt, Stuttgart. 7. PIRAZOLI, M. “Chine”. Office du Livre, Fribourg. 8. STIERLIN, H. “Enciclopedia of World Architecture”. Taschen. 9. STIERLIN, H. “Islamic India”. Taschen. 10.TILLOTSON, G. “Mughal India”. Penguin.

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Chapter 9. THE PERFECT SYMBIOSES FORM-FUNCTION IN THE HIGH BAROQUE ARCHITECTURE

The Council of Trento (1563) ended its sessions establishing a block of dogmas, rules and recommendations, intended to channel not only the thought of Church but also its way to pronounce itself, to act and to appear before the people and the powers. The Council was of no use to heal the wounds received during the religious schism, but it was of use to delimit a solid territorial barrier within which the official beliefs and impositions remained unconquerable. The governments and the monarchies would collaborate actively in the repression of the heresies and the new religious companies of militant type would be sent on ferocious campaigns of evangelisation all over the world and inside their own territory. With respect to the architecture, the consequences were traumatic. The modern ideals defended by Alberti and Bramante were considered as of pagan tendency and alien to the religious devotion, and the rationalism that came with them, inappropriate to a dogmatic religion that had just reinforced its theological and immutable criteria. It was necessary to appeal to faith instead of reason and therefore, it was necessary to reach the heart instead of the mind. Vignola, whose Regola delle cinque ordini was published in 1562, had overnight become the most prestigious architect. He was ordered in 1564 to continue, in association with Piero Ligorio, the works of Saint Peter, and straight away, the most important work and new plan of the moment: the church for the Roman seat of the Company of Jesus. Il Gesu, begun in 1568, was designed in a purely Renaissance style since at that time there was no alternative solution and the Council just advised against using references to pagan temples. The Church had not been able to create an architectonic style so suddenly and had to use the tools within reach. The Company did not like Vignola, but the Pope Julio III protected him knowing his capacity and flexibility. However, for the first time, a humanist had to submit to religious and theological impositions when defining his design. The Jesuit Giovani Tristano controlled all the decisions and the cardinal Alexander Farnesio dared to change the designs including that of the façade. As Vignola’s

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Fig. 9.1. Proposal by Vignola for the Church of Il Gesu, in Rome (Wittkover).

façade, serene and classic, was changed for Giacomo della Porta's, whose project was less imaginative and more superficial. What was left of the freedom that Michelangelo had taken until the limit? Suddenly, the ideas the pioneers had fought for were subordinated to a flat and totalitarian ideology. The vaulted interior itself was in question. The Company preferred a church with a wooden carcass and a flat ceiling where the acoustic conditions were improved and reminded of the paleochristian basilicas (Fig. 9.1). From the structural point of view, we cannot consider this work a display and from the stylistic point of view, even less. It is solely merited by establishing a model in plan and section that was followed by the churches of the baroque. If Vignola submitted, were the rest going to act in a different way? Quickly, and still within Renaissance

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patterns, new types had to be invented to adapt to the new criteria. If the change of the Il Gesu front, heir to the triumphal arches, showed preference for a framed scenography, the circular plans became forbidden. The intelligence of Vignola saved them by resorting to axiality. The invention of the oval plan within a rectangle, so that from the outside it could not be seen as round, was a success. The watchers of the new orthodoxy rushed upon the solution to declare it a discovery of the Council. In the previous chapter, we have seen the small chapel of Saint Andrea in Via Flaminia (Fig. 6.72) and the Church of Saint Anne of the Grooms (Fig. 6.73). They were followed by Saint Giacomo degli Incurabili by Volterra of Capriani, of majestic dimensions (25.5 x 18.7 m) (Fig. 6.74) and the gigantic Saint Mary of Vicoforte of Mondovi by Ascanio Vitozzi, of 36 x 24 m (Fig. 6.75). We have seen too the speed with which the countries that defended the new dogmas adopted these elliptical solutions. Spain had been the country that had fought more for the celebration of Council and that had contributed more material . Considering this situation, although the texts kept on including, within the Renaissance, works that exceed the year 1600, in these cases we must speak of

Renaissance only in the epidermis, but not in the content. Let us observe the difference between the Palladio of Saint Giorgio that follows a typical longitudinal scheme (Fig. 6.63) and The Redeemer, following rather Vignola’s model, although trying to safeguard Alberti’s ideal (Fig. 6.64). In any case, Venice never renounced its cosmopolitan vein. The fact that Palladio, in 1570, still wrote that the perfect shape was the round one, because “since all its points are at the same distance with respect to the centre, it is the most suitable to give testimony of the unity, the eternity, the uniformity and the justice of God”, did not prevent him from solving the Barbarian Shrine, of a perfect circular form, by means of surrounding it with a Latin cross that contradicted his intentions (Fig. 9.2). The Baroque, which term is subject to excessively frivolous speculations, starts when the ideas developed in the council were shaped in a map that related its intentions, forms and sensorial impacts. Not until Bernini merged architecture and sculpture was that achieved. With the addition of painting, the ideal fusion was obtained. Other sensations such as sound, light, smell, sight, theatre, choral representation and clothes were added later. For a long time I thought of the Baroque as a declining, confused and grotesque style created to deceive the masses and to feed their irrational mystic. It was not until the meticulous study of its underlying matter convinced me of the unity of a complex that had clear keys, nowadays completely deciphered. Michelangelo was a key figure in this process: mystical, tormented, ascetic, visionary, prophetic and creative. When he reluctantly painted the Sistine Chapel ceiling, he opened a crack that neither his contemporaries nor his successors understood, until Borromini, somebody mentally close to him, did. The ceiling is not a painting, but a complete architecture. Using an innovating artifice, he preferred to use a fictitious structural reinforcement painted on a continuous surface (Fig. 9.3). Not only did he use those reinforcement arches, but he also crossed them with some straight cornices that delimit the extension of the room and turn out to be the only apparent hoops of all his architecture. He thus created a spatial net that turned a monotonous room into a rich set of nets made of interwoven ribs. Nothing to do with the vaults of Brunelleschi or Alberti. It was a radical invention that fills the space with the strength and the gravity that the Herculean figures try to overcome.

Fig. 9.2. Barbarian Shrine, by Palladio (Wundram and Pape).

Alien to the real architecture of the room, he imposed with the pilasters a rate of alternate separation, hierarchising the whole structure. The alternating cornice made the ceiling seem higher. The disposition of the figures contributes it. They are figures of a much accentuated volume, modelled to face people. The sibyls and the prophets pretend to be vertical as if they were not in the vault. Ending the cornice, the

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Fig. 9.3. Ceiling of the Sistine Chapel, by Michelangelo (before restoration).

twenty ignudes play the same role as a row of statues crowning a building. The vault is thus reduced to less than a third of its surface and therefore seems very distant, so far that up there, between the openings of the structure, the first scenes of the Creation can be seen. It is so far in distance and time. The Sistine Chapel ceiling combines for the first time architecture, sculpture and painting in an indissoluble whole, whether it be in a virtual way. Perhaps the theologians of Trent were more bothered by the nudes of the set and were not able to see that Michelangelo had just written his architectonic programme. No matter how many concessions we are willing to make, it is a fact that until the appearance of Borromini the baroque did not fully exist in architecture. Even Bernini, so splendid in sculpture, made too many stylistic concessions in architecture. Bernini was a great architect of the later Renaissance that hardly let the fury of his disciple Borromini contaminate him. So, until 1630 nothing specially new happened in architecture. What has all this to do with the structural conception of the buildings? Did the Council also give instructions on the matter? Evidently not, but the evolution of the forms had to be made in accordance with their static characteristics. What happened was that in spite of the grandiloquent and propagandistic interest, the dimension of the spaces is virtual. They may give a sensation of amplitude and all the possible techniques are used to obtain it, but the physical dimensions are reduced. It means that structurally much more effective resources can be applied like that, than on a large scale: flat or waving ceilings, divided vaults, irregular macles, enormous holes, complex plans, etc. It is in the subtlety of the solutions where we find a field to work on. In this chapter, we will not mention specially the ornamental or sensorial aspects that the

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new architecture had established, but the geometrical effects, which will be materialised in all sorts of evocations. From this viewpoint the Baroque, which has so many different ways to express itself depending on the different regions, wins a firmer unity. The Baroque is the style of the Counter Reformation. The catholic countries let it develop its pomposity. It is in Italy, Spain, Portugal, the Iberian colonies, the South of Germany and many countries of Eastern Europe where it thrives. It only appears in France when this country solves its religious problem. The rest of the countries are more self-controlled. England for example develops a very classic, but not non-imaginative, Baroque. France shows a rather particular case that opens a new front. The fact that the French did not accept Bernini’s proposals speaks of how little they agreed with the personalist and non-systematisable styles. Fig. 9.4 show Bernini’s sketches for the Louvre that were ignored by Le Vaux’s projects. We consider Borromini the inventor of the Baroque. Not because he was the official architect, whose patterns were an example for his generation, but as a source of ideas that, duly codified, were adopted by the commercial architects who received the commissions: Bernini, Cortona, Juvara... In the personal field, he was marginalized socially. His difficult character and his excessive expressionism did not make of him an easy companion. However, he was able to solve any problem, however impossible it might seem. The first exclusive work was that of Saint Carlino alle Quatro Fontane, in 1634. It was a minimal and difficult project. Fig. 9.5 shows its plan, in which what first draws one’s attention is the placing of the church in the most difficult point, the corner. Beside this curiosity, the small structure, that could have been solved as Vignola did in Saint Andrea (Fig. 6.72), waves in very complex faces.

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Fig. 9.4. Sketch by Bernini for the Louvre Palace (Blunt).

Borromini had already worked on Saint Peter in the service of Maderno, and in the Baldaquino and the Palace Barberini on that of Bernini. He was an experienced constructor. The plan was difficult to identify for those entering that space and Borromini decided to make a solid cornice to separate the first level from the rest and to allow the vision of the outline (Fig. 9.6), that is to say, he created a unitary space in which at second level some pendentives give way to an elliptical vault. In addition, the dome is perforated in five different points to permit illumination. The small dimension (15 x 10 m) of the dome and the thickness of the faces help to avoid possible damage. Fig. 9.7 compares the size of the central pillars of Saint Peter with the plan of this church, which in fact rests on eight supports as seen in Fig. 9.8. In order to maintain the imaginative vein that began in Saint Carlo, it is worth studying Saint Ivo della Sapienza, started in 1640 with its long courtyard corresponding to the Alexandrian Library and designed by Giacomo della Porta (Fig. 9.9a). In this space, it would have been easier to place the projected circular plan. This is what any other architect would have done. However, he chose a starred plan that miraculously fitted within (Fig. 9.9b). The star was generated by means of two triangles measuring 25 m a side, which resulted in an inner circle of 16.6 m. In this case, the dome leaves any known pattern. The vertices of the inner hexagon generate semicircular arches that are the basic wall elements, being any

horizontal section of this dome homothetic with the plan (Fig. 9.10). As in the previous case, the cornice that crowns the first level defines the form of the plan, since at ground level it is difficult to discover it. There are some more elements of reinforcement as a continuation of the face pilasters, but they are secondary (Fig. 9.11). The loads descend mainly along six ribs to arrive at the six corner pilasters (Fig. 9.12). So that, what we really have is a ribbed hexagonal dome, whose faces wave capriciously. Nothing to do yet with Brunelleschi’s domes nor even with Michelangelo’s. Although the dimensions are not of importance, the almost 17 m gap between two opposite load pilasters is too much for a construction made of such poor materials (bad bricks and worse mortar) to resist. For that reason, the pathology began from the moment of the construction. As the architect of the library, Borromini blamed the materials for the hard cracking that appeared in the set. Fig. 9.13 shows the cracking scheme of the set and Fig. 9.14, the Finite Elements analysis made by Croci. In case the form of the dome was considered a little capricious, the ending that crowns it have an oneiric form (Fig. 9.15). Borromini was one of those architects who was given seemingly impossible missions. In the restoration of Saint John of Letran, the paleochristian basilica that could not be demolished, he designed a transformation that did not reach the vault that had to replace the studwork, but it was not constructed. Fig. 9.16a shows

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Fig. 9.5. Final proposal by Borromini for Saint Carlino alle Quatro Fontane (Bosel and Frommel).

Fig. 9.6. Building section of Saint Carlino alle Quatro Fontane church (Castex).

Fig. 9.7. Sketch comparing the size of the central pillars of Saint Peter’s dome and Saint Carlino alle Quatro Fontane as a whole (Bosel and Frommel).

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Borromini's design for the section ending in a spherical cap, whereas Fig. 9.16b is the interpretation of this proposal made in Piranesi’s workshop. The Church of Saint Agnese in Navona Square, does not have a structural interest, although stylistically it is worth studying. It is characterised by the high drum and the pointed dome, which was new in itself (Fig. 9.17). The introduction of the towers as fundamental elements in the composition of the façade was a prelude to a substantial change in respect of the height in the construction of these elements. Although it is true that the big projects of the Renaissance always projected some tower, see Saint Peter in chapter 6, the fact that they were never constructed gives an idea of the interest in incorporating them. In fact, Saint Agnese developed the idea that Bernini had conceived in 1636 to finish Saint Peter (Fig. 9.18).

Fig. 9.8. Structural sketch of Saint Carlino alle Quatro Fontane (Escrig).

Fig. 9.9a. Proposal by Giacomo della Porta for Saint Ivo and the Alexandrian Library.

Beside these projects of churches, there was another facet in which he stood out: the construction of palaces and buildings for religious congregations. Fig. 9.19 shows the structure of the main hall of the Carpegna Palace, where in addition to the distributive solution which was able to increase the apparent size of the lot, with the artifice of an oval patio tangent to the façades, the hall with two narthex and the huge stairs prove his clear-sight. The central ribbed structure was pioneering for Baroque structures.

Fig. 9.9b. Solution by Borromini for the church of Saint Ivo della Sapienza (Bosel and Frommel).

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Fig. 9.10. Drawing by Borromini for the dome of Saint Ivo (Bosel and Frommel).

Fig. 9.11. Building section in perspective from Saint Ivo (Catex).

The Saint Philippe Neri Oratory is another contemporary example that gives us an advantage: having been constructed, we can observe there the complex hierarchy of faces and spans (Fig. 9.20), as in Saint Mary of the Seven Pains (Fig. 9.21). Where this model reaches the maximum refinement is in the School of Propaganda Fide (Fig. 9.22). The Chapel of Three Kings solved the contradictions underlying all his previous solutions in which the structures were formed by trimmered ribs. Now all the ribs are continuous, going from support to support and, what is more interesting, all are equal and transmit the same load. Solving within a rectangular ground plan required great ability, mainly because the corners look very strange. Nevertheless, Borromini places the entrances in the corners and in their upper part, a small arch that matches two ribs in the same way as in the centre of the faces. The result is that the cover rests on twelve points in such a way that among them there are both big and small arches as in that alternate sequence so characteristic of the Baroque (Fig. 9.23).

Fig. 9.12. Structural sketch of Saint Ivo (Escrig).

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The other great architects of those days, in spite of their doubtless contributions, do not reach so exquisite levels. We are speaking of Pietro of Cortona, Carlo

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Crack pattern on the plan of the building

Crack pattern of the vault

Fig. 9.13. Pathology of the Alexandrian building of Saint Ivo (Croci).

Rainaldi and Bernini himself, who turned Saint Andrew of the Quirinal (1658-70) into his most controversial work by using an oval ground plan with its main axis in the short direction, with the dimensions 25 x 17.5 m (Fig. 9.24). It would not be anything special but for being divided in ten sections that give it an atypical modulation, since the Renaissance uses multiples of four exclusively. The new stayle influences the decoration. At this point, one hundred years after the Council, we can already put forward some of the basic characteristics of the Baroque, some already described, and others to be seen below:

Fig. 9.14. Analysis of the structural behaviour by Finite Elements (Croci).

1. Predominance of the solutions with a single axis of symmetry. 2. Extremely complex ground plans, where the spaces are very interrelated. 3. Multiplication of the levels in height. 4. Waving forms in ground plan and section. 6. Violation and free use of the classic orders. 7. An almost exclusive use of bricks as a structural material and a poor furring with very worked surfacing. 8. Complicated structures that use elements from every culture and, in many occasions, innovative elements. 9. Introduction of elements in height, whether they be towers or domes very deformed in elevation. 10.Scenographical and perspectival character of every element with a special use of several simultaneous vanishing points. 11. Synthesis of all the plastic arts and extensive use of colour.

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Fig. 9.15. Drawing of the Saint Ivo dome and lantern (Bosel and Frommel).

Fig. 9.16a. Proposal by Borromini for Saint John of Letran (Bosel and Frommel).

Fig. 9.16b. Saint John of Letran reconstruction by Piranesi of Borromini’s not constructed project (Bosel and Frommel).

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Fig. 9.17. Structural sketch of Saint Agnese, in Navona Square (Escrig).

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Fig. 9.20. Building sketch of the Saint Philippe Neri Oratory (Castex). Fig. 9.18. Bernini’s project for Saint Peter’s finishing (Toman).

Fig. 9.21. Building sketch of Saint Mary of the Seven Pains (Castex).

In addition, we must mention certain special features that only occur in the Baroque: 12.Lateral perforation of the domes to place oculos and windows. 13.Domes with several layers that look like a cascade. 14.Painted architectures that enlarge the space. 15.Better use of light reflections. Fig. 9.19. Structural sketch of the main hall of the Carpegna Palace (Escrig).

The first Roman Baroque can already be considered complete with these four great figures. But Rome, which

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Fig. 9.22. Building sketch of the School of Propaganda Fide (Castex).

Fig. 9.24. Building sketch of Bernini’s Church of Saint Andrea of the Quirinal (Escrig).

Venetian case is very singular and the plan itself, of rotunda with ambulatory and narthex, is typical of the purest Roman classicism. Also, the articulation of spaces is typical of the Baroque, since the ambulatory with its chapels and groined vaults is rather Brunelleschian than postcouncilian. Nonetheless, if we compared it with The Redentor (Fig. 6.64), very close to it, we would note the difference and the new contributions.

Fig. 9.23. Structural sketch of the School of Propaganda Fide chapel (Castex).

had finished the jubilee year in 1600, had an expanding capacity that logically radiated to the surroundings. Balthasar Longena built in Venice the Church of Saint Maria della Salute in 1631, dressing it with robes of Palladian look. Its outer aspect is imposing (Fig. 9.25); the interior, very sober, has a verticality in accordance with the characteristics previously enumerated (Fig. 9.26). In this case the structure consists of a very light hemispheric cover and the camber is obtained by means of a wooden dust cover in the style of Byzantine architecture. Although the Baroque features are masked inward, we must not forget that the

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The former Milanese Baroque was in certain ways ahead of the Roman, since Lombardy was a sworn enemy of classicism. We find an immediate explanation in the fact that Charles Borromeo, the greater council activist, was born there and published some detailed instructions with a practical purpose. They include ideas such as the following: “The churches have to be cruciform as seen in the big Roman Basilicas”; as well as others of formal content. Pellegrino Tibaldi, the architect of Charles Borromeo, was a faithful guardian of this orthodoxy just like his successor Martino Bassi. The most important work that they undertook was the restoration of Saint Lorenzoe of Milan (Fig. 5.2), whose pointed vault, that replacing the Roman vault, had collapsed in 1573. Since the existing plan had to be respected, it adopted a scheme very similar to that of Saint Peter by Sangallo (Fig. 9.27), which materialised in a project like that of Fig. 9.28, on an octagon of 15 m radius and a pointed dome 25 m high, that is to say, practically circumscribable in an equilateral triangle (Fig. 9.29). If it had been a revolution form, the analyses as shell would have resulted in a traction in the base between 0.2 and 0.3

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Fig. 9.25. General view of Longena’s Church of Saint Maria della Salute (Escrig).

Fig. 9.27. Tibaldi’s project for Saint Lorenzo, in Milan (Lotz).

Fig. 9.26. Plan and section of Longena’s Church of Saint Maria della Salute (Wittkover).

Fig. 9.28. Developed project for Saint Lorenzo, in Milan (Cardinali).

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N/mm2, depending on whether we consider or not the weight of the cupola, and the final result, not considering the traction of the material, is an outward thrust of 1 tonne. Not being a revolution form, we can consider the thrust of each one of the eight ribs of 12 tonnes, which is a small amount in comparison with spanned space. However, the problem is not so simple. For a start, because the set into the base is very flexible and the existence of the windows debilitates the stretches. Thanks to the documents that exists on this construction, we can study the state of the analytical technique at this time. Martino Bassi had to justify in detail his static approach to its opponents Magenta and Rinaldi. Of course, this justification was reduced to the hypotheses of proportionality between the resistance of the material and its weight, and the relation between the supports and descendent load sections, and the experience from other buildings, and the texts of treatise writers. On the other hand, from the beginning steel hoops were placed as seen in Fig. 9.28. In 1771, the mathematician Bernardino Ferrari used the knowledge of the time to make the analysis shown in Fig. 9.30, which peculiarly correctly used the conditions of symmetry to reach the conclusion that the thrusts reached 8 tonnes in the base of each rib, slightly less than what we have previously predicted. Its conclusion was that the stability of the whole could not be assured without the contribution of the corner towers. In 1995, Cardinale and others set out a calculation by Finite Elements very similar to that proposed by Ferrari two hundred years before (Fig. 9.31) which concluded what can be seen in Fig. 9.32, where the greater tensions take place in the base and also with a value of 0.15 N/mm2. Note that the compressions in these graphs are of positive sign.

Fig. 9.29. Analytical sketch by Bassi for the behaviour of the dome of Saint Lorenzo, in Milan (Escrig).

Fig. 9.30. Analysis by Ferrari for the same dome (Cardinali).

We find a close correspondence among all the analyses that we have done, and the value of these modern tools is that they provide much detail in each of the points. In Piedmont, the church of Saint Mary of Vicoforte, begun in 1596 and finished in 1733, is a magnificent example of a Baroque construction. Its outer aspect, large dimensions and motley inner decoration make of it a clear example of the former Baroque that evolved in all its phases, due to the length of its construction. The elliptical interior of the dome has a span of 37 x 24 m, which makes it the greatest elliptical dome ever constructed, including present concrete shells (Fig. 9.33). The dome construction did not begin until 1731, being finished in six months. It has an average thickness of 1.7 m. and was constructed with bricks and ribbing towards the outside. The inner spectacle (Fig. 9.34) and the outer aspect (Fig. 9.35) is moving.

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The construction problems did not consist only of the big efforts it had to undergo, including strong flexion momenta (Fig. 9.36), but also that it was based on uneven ground under which flowed a stream. That meant that the foundations were crossed by accessible underground channels of drainage that kept the ground dry. Nevertheless, the neglect of many years and their obstruction triggered differential settlings that led to the alarming pathology shown in Fig. 9.37. The most amazing thing is that such a complex work was constructed in a province by order of an individual, no matter that he was the Duke of Savoy, and by an architect with hardly a known work except for some military fortifications.

The Perfect Symbioses Form-Function in the High Baroque Architecture

Fig. 9.31. Discretisation for the Finite Elements calculation of Saint Lorenzo dome (Cardinali).

Fig. 9.32. Results obtained from the calculation (Cardinali).

The thickness of the shell, little in relation to the span, the decisions to solve the discontinuity of the oculos and the small buttresses characterise a work that the historians have marginalised for being eclectic but that the contemporary architects would have to study profusely.

specially gifted mind a process of general conciliation must have been elaborated. If Guarini had not left Italy we probably would not have had the architect that we know. It is important for that reason to know his movements.

The XVIIth century was especially hard for the European population and economy. Most of the countries were devastated by epidemics and crisis. Although Italy was safer, its economy also suffered. Nevertheless Piedmont, under the good government of the House of Savoy, saw the flourishing of a golden age for architecture. We have already seen Vitozzi’s role, who was succeeded by Guarini a generation later, as court architect.

In 1639 he entered the order of the Theatines in Modena, from there he went to Rome where he knew the first work by Borromini. In 1647 he returned to Modena to be ordained a priest. In 1657 he went to Spain and Portugal, where he left his mark and learned from the Islamic architecture. In 1662 he travelled to Paris, from where he was called to Turin by Carlo Emanuel II, living there for his remaining seventeen years of life. We have given this account to locate the following projects.

Guarino Guarini, monk, mathematician and architect, tried simultaneously to conciliate these three approaches, vital, scientific and technical, in the rationalist philosophy of Descartes, whose work he knew in Paris. More likely, there he fell in love with the French Gothic style to such extent that in his

Fig. 9.38 shows the basilical scheme of the 1656 Divine Providence Church in Lisbon. The way he solved the plan was original. The vaults are built with diagonal ribbings and the transept of elliptical endings is combined to form a unitary space . The waving façade of Saint Charles of Borromini spreads over the whole

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Fig. 9.35. Outer aspect of Saint Mary of Vicoforte (Escrig).

Fig. 9.33. Building sketch of Mondovi’s Saint Mary of Vicoforte (Pizzetti).

Fig. 9.36. Flexion momenta obtained by Finite Elements, for the restoration project of Saint Mary of Vicoforte (Pizzetti and Fea).

building in ground plan and elevation. The irregular patterns of the adjacent spaces, the rate of alternating reburied columns and a general form of swell or soft surface, inaugurates a style that Borromini only dared to use on the outside. The straight line has disappeared and not even the arches are flat. This early church gathers all the typical elements of XVIIIth century Central European Baroque architecture. The Church of the Somasco in Mesina uses a starred pattern that would later be repeated in numerous works. It is interesting that on the outside there are no domes, only staggered blocks as in a ziggurat. The drum totally hides the main dome and the six supports of the dome are formed by the grouping of three columns (Fig. 9.39).

Fig. 9.34. Upward vanishing plan of Saint Mary of Vicoforte (Escrig).

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In the Royal Saint Anne in Paris, dating from 1662, the series of Gothic ribbing arches define the main dome that, in addition, is developed in three levels. The drum, with its pairing rate, is treated as a face at ground level. The dome has a double starred pattern, in this case of octagonal type. And the third level dome is the only one that presents some conventional support for the high lantern. The great development in height is not done by elevating the drums and pointing the domes, as Pietro of Cortona had done, but by superimposing many levels. This way, the whole has a very Eastern appearance untypical of Italian architecture. To complicate the work a bit more, the

The Perfect Symbioses Form-Function in the High Baroque Architecture

Fig. 9.37. Project for the Divine Providence Church in Lisbon, by Guarino Guarini (Meek).

Greek cross plan arms are covered with ribbed elliptical domes in a geometrical interaction to be studied in plan (Fig. 9.40). Dating from 1667, we find another surprising small work, the Chapel of the Turin Shroud Sindone (Fig. 9.41). In this case, despite its small dimensions, the 15 m in diameter plan is enlarged in height to the point of looking endless by means of the artifices that we are going to describe. When Guarini took charge of this chapel, it already had been built up to the first cornice with an octagonal modulation. With his

outstanding ability, he succeeded in implanting an enneagonal modulation so as to erect a dome on three transverse arches, with hardly any modifications in the constructed faces. The drum becomes complex with six paired columns ending in arches. From that point, the dome is closing by means of superimposing arches that always rest in the keystone of the inferior level, doing this for six levels until arriving at a circular cornice on which rests a small dome of vegetal aspect, made of a mesh that lets the light of a small lantern pass through (Fig. 9.42a). The interior has a magical aspect derived from its structural bareness in which

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Fig. 9.38. Church of the Somasco, in Mesina, by Guarino Guarini (Meek).

the forces spread along multiple arms as an unfolded fold-out (Fig. 9.42b). The exterior, with its waving drum and its eastern looking ending, like that of a pagoda with abutted hollows, is at least oneiric and surrealist (Fig. 9.43). We are not talking, of course, of dimensions that put the structure under risk, but at least this is complex and reminds us of the aspects seen in Chapter 8 about trimmered Chinese architecture. The Church of Saint Lorenzo, close in style to the Chapel of the Turin S. Sindone, is even more spectacular for being less sculptoral and having more architectonical definition (Fig. 9.44). It reflects too the influence of Borromini in Saint Ivo. In that case, the initial polygon is a hexagon and in this it is an octagon; in that case, the sides were alternatively concave and convex, and in this they are all concave. Once again, it made extensive use of the multiplicity of levels so that each one of them is a new surprise. It seems that at the ground level all the loads are transmitted by

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sixteen slender columns; in fact, it is practically like that, which demands a very light shell. Eight great concave arches on these columns transmit the loads. We know the disadvantages of these wedging arches and for that reason they should be discharged. Cleverly, the cornice on them is straight, and from here start the four trapezoidal trumpet shells that conform to the four transverse arches supporting the small drum on which the dome rests. As is usual with Guarini, the dome is ribbed and, although very cambered in this case, inspired by the Mosque of Cordova. There are sixteen starred bending ribs that, by means of the trumpet shells, rest on the vertical of the columns. Between the ribbings there are openings in all the spaces so that the dome becomes a network that catches the sifted light. As in previous cases, the thrusts of the ribs are derived towards the vertical by means of a drum load that hides the curvature from the outside, allowing additionally a gigantic lantern, also solved with ribbings, and ending in a cupola that is also perforated (Fig. 9.45).

The Perfect Symbioses Form-Function in the High Baroque Architecture

Fig. 9.39. Project for the Royal Saint Anne, in Paris, by Guarino Guarini (Meek).

Fig. 9.40. Chapel of the S. Sindone in Turin (Meek).

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Fig. 9.41. Structural sketch of the S. Sindone in Turin (Escrig).

Fig. 9.43. Structural system of the Turin S. Sindone in Turin, seen from outside (Escrig).

Fig. 9.42. Design proposal for the S. Sindone in Turin, from unfolded paper (Escrig).

We are studying in this text mainly the structural aspects, so that we are not going to insist on the spatiality, the form and the light. But we must say that this church is the ideal Baroque synthesis that in addition has an associated spaces complexity of the maximum interest. Guarini was an expert constructer who tried new constructive processes to allow him to

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build his fantasies with the same resources. The construction of Saint Lorenzo is well documented, so that we know that hollow ribs and chambered vaults were used (Fig. 9.46). Bernardo Vittone published in 1737 a compendium of his teacher’s projects that proves his capacity for experimentation and his knowledge of geometry: there we find basilical plans like that of Saint Philippe Neri in Turin, which means a brief incursion in the longitudinal plan of unitary spaces (Fig. 9.47); or experimental projections of the same type (Fig. 9.48); or centralised plans whose spaces he governs with absolute mastery, as the Sanctuary of Oropa (Fig. 9.48); and even centralised regular plans never before experienced, like the pentagonal one of Saint Gaetano of Nice (Fig. 9.49) or the eliptical one of Saint Mary of Nice (Fig. 9.50). The polynuclear plans are an unusual new way: Saint Phillipe Neri in Casale of Monferrato (Fig. 9.52) or Saint Gaetano of Vicenza (Fig. 9.53). Nothing like Leonardo’s bubbles plans, which submitted in hierarchy to a central one. Also, in civil architecture he made great contributions most likely influencing Central European palaces in Juvara or even the French ones, although it might be that he was influenced by them.

The Perfect Symbioses Form-Function in the High Baroque Architecture

Fig. 9.44a. Church of Saint Lorenzo, in Turin, by Guarino Guarini (Meek).

The 1682 Racconigi Palace in Carignano, with its great central hall illuminated from the ceiling, is an example of this potential. The Carignano Palace in Turin, shows a tangent hall that will be an example for many others (Fig. 9 .54). The indirect illumination falling from above through a hanging ceiling rose stands out among other details. Guarini shows that besides being a master of geometry, construction, ornamentation and design, he was also one in light treatment. We must also highlight his talent as a theoretician, since in his period of treatise writer he wrote about his perspective discoveries and his representation techniques, as well as his constructive discoveries. Maybe he was not as good a draftsman as Borromini or Bernini, but his capacity for planimetrical expression was at least equal to that of the perspective and scenography draftsmen of the time. His treatise Architettura Civile, published in 1737, fifty years after his death, with drawings ascribed to the young architect Bernardo Vittone, summarises many of his designs in a way only obtained before by Palladio.

This work completes the Disssegni d´architettura civile et eclesiastica from 1686, that had no text. In 1671 he had already published Euclides adautus & methodicus mathematicae, a text of seven hundred pages and a summary of philosophical and mathematical ideas. In 1674 he published the mainly practical text Il modo de misurare le fabriche, in fact, a book of measurements and valuations. Still in 1677, he published the Trattato di fortificatione che ora si usa in Fiandra, Francia et Italia, in addition to theatre plays and works of literature. It is curious, among other things, that he calls himself Matematico dell´Altezza Reale di Savoia. What happened meanwhile in other countries? In Spain, the XVIth century had been flourishing and Charles V first and Philippe II later imposed an austere style that made substantial contributions to the Renaissance. The XVIIth century, as in the rest of Europe, was chaotic. To the epidemics, famines, economic crises and failings of the colonial exploitation, we must add the incessant wars to defend the territories that were

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Fig. 9.44a and 9.44b. Church of Saint Lorenzo, in Turin, by Guarino Guarini (Meek) (Escrig).

to be lost. The Herrerian style was kept in the centre of the country, whereas a decorativist classicism was developed in the periphery. It is not worth the trouble to underline anything from the space and structural point of view. In any case, Italian architecture is well illustrated with the books of Serlio, Scamozzi, Palladio and Vignola.

Fig. 9.45. Building detail drawn by Vittone for Saint Lorenzo, in Turin (Meek).

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In France the matter was different. Though there existed the same demographic and social problems, it was a country in a period of consolidation that from Henry IV to Louis XIV made a great effort to become a modern nation. The French Baroque has its particular characteristics. We have already seen the rejection of Bernini and Palladio, two extreme cases. On the other hand, the new state decided to keep out of the religious conflicts, not using therefore this type of architecture to materialise its great projects. The urban renovation and the civil buildings concentrated its activities. Mansart and Lemercier took some of Cortona’s style, and were imaginative but never baroque in the big castles (Fig. 9.55). They still have

The Perfect Symbioses Form-Function in the High Baroque Architecture

Fig. 9.46. Saint Philippe Neri, in Turin, by Guarino Guarini (Meek).

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Fig. 9.47. Sanctuary of Oropa, by Guarino Guarini (Meek).

Fig. 9.48. Saint Gaetano of Nice, by Guarino Guarini (Meek).

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Fig. 9.49. Saint Mary of Nice, by Guarino Guarini (Meek).

Fig. 9.50. Saint Philippe Neri, in Casale de Monferrato, by Guarino Guarini (Meek).

Fig. 9.51. Saint Gaetano of Vicenza, by Guarino Guarini (Meek).

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Fig. 9.52. Bubbles plans, by Guarini Guarini (Meek).

Fig. 9.53. Raccognini Palace, in Carignano, by Guarino Guarini (Meek).

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a medieval concept of architecture by the lack of unity of the parts. Fig. 9.56 shows the project of a staircase dome by Mansart for Blois, dating from 1635, and previous to some Italian similar proposals. Fig. 9.57 shows the plan of the Palace of Vaux-le-Viconte, from 1657, out of which Guarini might have taken the idea of some of the palaces that came later. The scheme of Mansart for the burial Chapel of Saint Denís dates from 1665 (Fig. 9.55). This model would be followed in the Church of Les Invalides, initiating thus the three shells dome with indirect illumination scheme (Fig. 5.58). This dome is 28 m in diameter and has a profile in catenary that anticipates that projected by Cristopher Wren ten years later with a very similar scheme.

Fig. 9.54. Carignano Palace, in Turin, by Guarino Guarini (Escrig).

Fig. 9.55. Sketches by Mansart for the burial chapel of Saint Denis (Toman).

Fig. 9.56. Dome of a staircase in Blois, by Mansart (Blunt).

In England, the undisputed figure in this is Wren, his Saint Paul's Cathedral being the most outstanding work of those years in Europe. In this case, the dome was first projected in 1673, measuring 32 m in diameter and having the centralised cellular plan seen in Fig. 9.59 in the denominated Great Model, whose scale model we can see in Fig. 9.60. Later on, this model was substituted by a basilical one with a very particular dome (Fig. 9.62) that avoided the buttresses to arrive finally at the present design, which conserved that plan (Fig. 9.63) but came much closer to Saint Peter´s profile. In this design the dome is triple, as in The Disabled (Fig. 9.64), anticipating the final construction. The 32 m was not changed, and the knowledge of the pathology that was then appearing in Saint Peter works and the subsequent mathematical discussions seen in Chapter 6 gave much weight in the final profile decision. The inner of the three shells is hemispherical with a big oculo, the following one is conical with a rounded vertex and the outer is a skin on a studwork (Figs. 9.65 and 9.66). Wren was the scientific chairman of the Royal Society, of which Robert Hooke was then the secretary and Isaac Newton a member who later succeeded him. Therefore the importance that Wren attached to the tracing of the resistant curve that Hooke suggested to him to be that of the hanging thread having a width equal to the diameter and the height of the whole building. This was a very cambered catenary, with a relation of 2:1, which tracing had to be within the central nucleus of the sections. This is not exactly so, but is the best that could be done with simple geometries. The general aspect is very classical and the Baroque concessions, being very clear in the Great Model, are hardly found in the final work. England never fully joined the Baroque craziness except for the features of some spaces. Ornamentally, the architects were severe and some Gothic elements never disappeared. Saint Peter's basilical plan itself was reminiscent of the Gothic cathedral which it replaced. We have already said that the religion of each territory defined much of the architectonic characteristics and England was not in the catholic sphere.

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Fig. 9.57. Palace of Vaux-le-Viconte (Blunt).

Fig. 9.59. Former project by Wren for Saint Paul’s, in London (Summerson).

Fig. 9.58. Church of Les Invalides, in Paris, by Mansart (Blunt).

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Fig. 9.60. Wooden Great Model of the former project by Wren for Saint Paul’s (Summerson).

The Perfect Symbioses Form-Function in the High Baroque Architecture

Fig. 9.61. Project with a cimborrio dome by Wren for Saint Paul’s (Summerson).

Fig. 9.62. Approach to Wren’s final project for Saint Paul’s (Summerson).

This work was finished shortly after 1700, a year that marks the separation between the High Baroque and the Full Baroque, which we will see in the following chapter.

Fig. 9.63. Sketch by Wren for a three shells dome (Summerson).

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REFERENCES OF CHAPTER 9

Fig. 9.64. Approaching to the catenary shape of the resistant profile of Saint Paul’s dome (Summerson).

Fig. 9.65. Sketch of the final project, wherein the catenary curve going from the crowning to the base is stood out with a thickest line (Escrig).

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1. ESCRIG, F. “Tecnología en los edificios históricos”. STAR, Structural Architecture nº 2, Universidad de Sevilla. 2. HEINLE, E.& SCHLAICH, J. “Kuppeln”. Deutsche Verlags-Anstalt, Stuttgart. 3. WITTKOVER, R. “Arte y Arquitectura en Italia 16001750”. Manuales de Arte Catedra. Ed. Cátedra, Madrid. 4. PIZZETTI & FEA “Restoration and Strengthening of the Elliptical Dome of Vicoforte Sanctuary”. Domes from Antiquity to the Present, IASS Symposium, Istanbul, 1988. 5. BLUNT, A. “Arte y Arquitectura en Francia 15001700”. Manuales de Arte Cátedra, Ed. Cátedra, Madrid. 6. SUMMERSON, J. “Architecture in Britain 15301830”. Penguin Books Ltd, London. 7. ESCRIG, F. “Towers and Domes in Architecture”. WIT Press, Southampton. 8. CASTEX, J. “Renacimiento, Barroco y Clasicismo. Historia de la arquitectura 1420-1720”. Akal Ed, Madrid. 9. BOSEL, R. & FROMMEL, Ch. “Borromini e l´universo Barroco”. Electa, Milano. 10.WHINNEY, M. “Wren”. Thames and Hudson, London. 11. MEEK, H.A. “Guarino Guarini”. Electa, Milano. 12.CARDINALI, G. et al “The Dome of Basilica of San Lorenzo in Milano: A comparison between modern and ancient mathematical models”. Spatial Structures, Heritage, Present and Future. IASS Symposium 1995. Milan. 13.CROCI, G. et al “The Dome of St Ivo della Sapienza in Rome”. Spatial Structures, Heritage, Present and Future. IASS Symposium 1995, Milan. 14.MARK, R. “Architectural Technology up to the Scientific Revolution”. MIT Press, Cambridge, Mass. 15.TOMAN, R. “El Barroco”. Köeman, Colonia.

Scenographical Architecture of the 18th Century

Chapter 10. SCENOGRAPHICAL ARCHITECTURE OF THE 18th CENTURY

In 1667, Borromini, undergoing a worsening in his mental disease, voluntarily put an end to his life when he was sixty-eight years old. Bernini survived thirteen years and Guarini eleven; Pietro of Cortona was almost contemporary. In a short space, the Roman architecture was orphaned since neither Rainaldi nor Carlo Fontana had enough imagination, not even to be continuers of the previous line. The continuation, whenever it took place, was no longer going to develop in Rome, whose vitality had flagged. On the other hand many political facts of great importance had taken place. After the death in 1700 of the last of the Spanish Habsburgs, a series of European wars broke out, affecting all the main powers. As a result, the Bourbons settled in Spain changing all its architectonic habits. Louis XIV of France saw in his later years the fading of the greatness he had worked so much for, and architecture became mundane and over elaborated in what has been contemptuously named, the Rococo. Germany snatched from France all the Central European territories and began to be, by means of Charles VI, a frustrated aspirant to the Spanish crown, a great power having its centre in Austria and dominating from the Netherlands to Milan and Naples, including Bohemia and Hungary. It was England that got the most out of the confrontations among all of them. Apart from consolidating its colonial empire, which had not existed until then, it kept the classic tradition, out of which had come some of its distinguishing marks and best results. In fact, it turned its eyes to Italy to look for the most refined classicist samples, finding them in Palladio. In this panorama, it is easy to set up a geography of the styles that characterises the Baroques different proposals. The thread sets off from Italy but quickly submerges in the local particularities. England evolved from Wren toward a bare classicism. France proposed a complex and grandiose style, also on the basis of a very classicist order. Spain, still too submitted to professional guilds, found it difficult to get rid of Herrera’s style, and the Bourbon impetus imported some derivations half Italian, half French. The Spanish Baroque, which was so rooted in the country,

found its origins in colonial architecture, as happened with Portuguese architecture that could never get rid of the Manuelino Gothic. It was the Centre of Europe, including the north of Italy, with a catholic tradition, that was the place where the Baroque expressed itself with the most oneiric, over elaborate and fantastic forms. In any case, there was a perfect delimitation between the centralist and lay states and the catholic ones. In Italy, the Dukedom of Savoy, cleverly administered by a government that obtained for Turin the rank of a great city, stands out at this moment, as well as Naples and Sicily, which under the alternate governments of the Habsburgs and the Bourbons, becomes an academy of future cultivated and modern kings. Therefore, 1700 is a decisive date for the changing of the Roman primacy. In 1707 Filippo Juvara, a Sicilian priest and draftsman born in 1768, presented a project to be admitted as an architect in the Academy of Saint Lucas in Rome, that was made under the direction of Carlo Fontana and based on Saint Agnes of Piazza Navona, the work by Borromini finished by Rainaldi (Fig. 10.1). The amazing thing is that in this academic project can be found the keys of the future style of a prolific and influential architect. A proof of his capacity for public relations, well known since 1701 when he organised the decoration of Mesina for the reception of Philippe V, the future Spanish monarch (Fig. 10.2), was the fact that in 1715 he was appointed First Civil Architect of Vittorio Amadeo II, Duke of Savoy, after having worked in a grandiose Royal Palace in Mesina to develop the Church of Superga (Fig. 10.3) that evidently resembles his degree project. His ability as a draftsman, at a time when the collectors leapt on illustrations and engravings with a hoarding obsession, made him very popular. A superficial look at Superga reveals a deep classicism: orders of a rigorous Renaissance tendency, correspondence between the outside shapes and the inner spaces, centralised plan of octagonal modulation and Michelangelo buttresses. Although his origins must

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Fig. 10.3a. Juvara’s drawing for the Church of Superga (Bonet Correa).

Fig. 10.1. Juvara’s project for his Academy of Saint Lucas examination, from 1687 (Bonet Correa).

Fig. 10.2. Decoration prepared for the reception of Philippe V in Mesina, in 1701 (Bonet Correa).

Fig. 10.3b. Juvara’s project for the Church of Superga (Bonet Correa).

be looked for in Borromini, as we have already seen, his waving façades do not follow him. The access through a columned portico, like a hall, and its connection to a back courtyard as that of Saint Ivo, stresses and contradicts his belonging to the Roman High Baroque (Fig. 10.4). Nevertheless, as for its elevation, it is fully Baroque.

the transverse arches until their keystones. The drum is extremely high and very bright and the dome is double shelled, slightly cambered like those built by De la Porta, and with a springing perforated with oculos. The inner decoration is like that of Bernini, carried out by means of hexagons (Fig. 10.5). The towers complete this baroque look.

For a start, inwards there is a giant order that surpasses

Anyway, Superga is not important for being a great

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Fig. 10.4. Plan of the whole building of Superga (Bonet Correa).

Fig. 10.6. Building perspective of the Superga dome (Gritella).

Fig. 10.5. Section of the Superga dome (Bonet Correa).

Fig. 10.7. Preliminary drawings by Juvara for the project of the Cathedral of Turin (Gritella).

structure, since the dome diameter hardly reaches ten metres, but for its grandiose look achieved with very few resources. Fig. 10.6 shows the constructive scheme that, obviously, goes without cradling.

constructive possibilities. The Palace of Stupinigi is an example of this (Fig. 10.9). Its centre is an elliptical hall resting on four buttresses with a gap between them of 15 m and a skin that wraps them without producing niches (Fig. 10.10). The central dome is a conventional squinched one with such a painted architectonic decoration as to look much richer than it really is (Fig. 10.11). In fact, the general decoration is painted, so that the magnificence of the space is fictitious. However, there is a determination to stand the cornices out more typical of Borromini than of Guarini who, because of his geographical proximity, should have influenced more. Stupinigi is a Full Baroque typical model.

If we enlarge the scale and focus the first project on the Turin Cathedral (1726), we will see that this one also stays with the Saint Peter model (Fig. 10.7) in spite of the vertical unity that gives to the central cylinder (Fig. 10.8). Juvara lived in permanent contradiction between his classic vocation and his longing for newness. His vast architectonical culture makes him borrow from all the styles and his expressive skilfulness bring him beyond his

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Fig. 10.8. Section through the transept of the Cathedral of Turin (Gritella). Fig. 10.10. Sketch for the main hall of Stupinigi. Drawing by Juvara (Gritella).

Fig. 10.9. General proposal for the Stupinigi Palace. Drawing by Juvara (Bonet Correa).

If we compare Guarini´s Saint Philippe Neri (Fig. 5.47) with that by Juvara (Fig. 10.12a and b), we clearly see the difference. Guarini´s is more rigid in plan and imaginative in elevation. Juvara’s is just the opposite, though the project finally built was very conventional. It is in the plans where Juvara looks more transgressor. In Saint Anthony in Chieri, for example, the absence of transverse arches gives the plan a unity that will not become general until the Central European Baroque (Fig. 10.13). Through this artifice, it seems that architecture accepts the inner space (Fig. 10.14). In the treatment of light, he also introduces innovations in respect of Guarini, by means of the light boxes system, which pours light vertically through the annex spaces. In the Carmine, having a very unitary plan (Fig. 4.15), the openings to illuminate the barrel vault are not solved with lunettes, but with domes with oculos in the side chapels (Fig. 10.16). His invention will be frequently used in the later Italian and Iberian architecture. Juvara was a scenographer before being an architect and this can be guessed from his architecture (Fig. 10.17) since he always uses decorative skins and architectonical images by contemporary draftsmen on the construction. From Fernando Bibiena he took the liking to the 45º perspective, applying it even to some constructive elements such as cornered pilasters and chapels (Fig. 10.18).

Fig. 10.11. Aspect of the main hall of Stupinigi, in a contemporary painting (Bonet Correa).

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Turin’s architecture is important due to the influence that it had all over Europe. When Philippe V ascended the Spanish throne, Juvara was called to his court where, in just two years, he revolutionised the architectonical panorama together with an illustrious group of Italian architects formed under his influence.

Scenographical Architecture of the 18th Century

Fig. 10.12. Saint Philippe Neri project by Juvara (Pomer).

Proof of how freely plans could be carried through is Saint John and Saint Remigio of Carignano, a work by Juvara’s disciple Alfieri. It is an extremely curious minimal church of toroidal shape and a 10 m span (Fig. 10.19). To complete the Piedmont cycle we are going to speak

of Bernardo Vittone (1702-1770), a much later architect. He studied too at the Saint Lucas Academy, where he got his degree in 1732, going back to Turin in Juvara’s last years. His career, however promising, was outshone by other court architects’, cleverer than him in public relations, so that he never had enough acknowledgements.

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Fig. 10.13. Saint Anthony in Chieri (Pomer).

Fig. 10.14. Inner view of Saint Anthony in Chieri (Escrig).

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Fig. 10.15. Preliminary outline by Juvara for the Carmine (Gritella).

Fig. 10.17. Juvara’s scenery (Viale Ferrero).

Fig. 10.18. Ideal project by Juvara (Gritella).

Fig. 10.16. Architectonic section of the Carmine (Escrig).

Fig. 10.19. Inner view of Alfieri’s Saint John and Saint Remigio, in Carignano (Escrig).

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Fig. 10.20. Vittone’s project for the Chapel of the Visitation, in Vallinoto (Wittcower).

Fig. 10.21a. Inner view of the Chapel of the Visitation, in Vallinoto (Escrig).

He made lots of projects of little churches and chapels for religious congregations and used his skill to exploit the centralised plan possibilities to the full. It is a cliché to say that he represented a balance between Juvara and Guarini since, in fact, he represented a new way that had very few continuers because, among other reasons, being at the gates of the neoclassical architecture and in parallel to the rococo one, no one cared about his lucid dissection of the spatial possibilities of an architecture so rigorous and complex.

easily accessible information.

In 1735 he was ordered to complete Guarini´s treatise “Civil architecture” drawing illustrations of his projects, coming therefore into contact with Guarini´s approach and using at the same time a large amount of not

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There is no foundation to accept, as insinuated, that he was a little formed and provincial architect, and his scarce graphical skill was balanced by his constructive knowledge. Why do we spend so much time on an architect who hardly built anything of importance and whose developing period cannot have influenced the great European contemporaries? There were other more imaginative architects who wore themselves out with only one work. His first important work was the Chapel of the Visitation in Vallinoto, from 1738 (Fig. 10.20). It is an extremely

Scenographical Architecture of the 18th Century

Fig. 10.21b. Structural section of the Chapel of the Visitation, in Vallinoto (Escrig).

Fig. 10.22. Sanctuary of Kappel, near Waldassen, by Dienzenhofer (Norberg Schulz).

small piece, made of poor materials and extremely poorly finished. However, all these limitations are not enough to diminish the impression produced by its inner look.

What is amazing in this project is the three shells dome system. The first one is a floating starred mesh with bricked ribs, which behaves as a net to fish light (Fig. 10.21a). The second one is a cap with an oculo over which falls a light torrent of which we do not know the source since it is the third one, slightly cambered, that has six openings to illuminate that empty chamber invisible to the observer. Between the first and the second one there are some invisible illumination hollows equivalent to the windows of a non-existent drum. The three side chapels are illuminated in vertical, in three cases on balustered galleries, in the other three directly to the floor (Fig. 10.21b). The starred system, the hexagonal plan with attached circular niches and the ziggurat shape give a rigidity to the whole typical of a structures master.

This building displays two evident influences: Guarini’s plan and part of the dome system of Saint Ivo and Juvara’s light treatment. He also completely eliminates the cornices continuity and even in the side niches leans them to give a depth and perspective sensation, whereby gets away from both of them. The two influences are obvious since he had known everything about Guarini when engraving his projects and witnessed Juvara’s finishing of the Carmine and its light boxes. Therefore, we must not be amazed at the matter.

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Fig. 10.23. Sanctuary of Saint John Nepomuceno, in Saar (Bohemia), by Aichel (Escrig).

It seems that Guarini was a very modest architect, free of envies or ambitions and satisfied with doing his works well, even when they were low budget projects or placed in rural areas. Except for those drawings made by us, the rest of them belong to the treatises that he wrote at the end of his life: “Instruzioni elementali”, published in 1760 and “Instruzioni diverse”, in 1766, a time in which there were dozens of treatise writers and, therefore, he could be of little influence. When comparing this project to that of Dienzerhofer in the Sanctuary of Kappel near Waldsassen, dating from 1684, we can observe the different way of using Guarini’s lessons (Fig. 10.22). In this case, all the contribution is just the four pieces of sphere macle

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Fig. 10.24. Saint Louis Gonzaga in Corteranzo, by Vittone (Norberg Schulz).

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Fig. 10.26. Saint Genevieve of Paris, by Souflot (Escrig).

Fig. 10.25. Saint Bernardino in Chieri, by Vittone (Escrig).

with three cupolas and the three towers that do not give directionality to the building, as well as some entrances through a covered exterior gallery of which it cannot be guessed the main one. The cornice totally breaks the lower level of the spheres springing and the spatiality is poor despite the complexity of the resources used. Dating from 1719, in the Sanctuary of Saint John Nepomuceno in Saar (Bohemia) a minor architect, Aichel, develops a starred pentagonal plan. It too is a heir of Guarini’s but has a larger spatiality and is very corrupted with a Gothic decoration (Fig. 10.23). It also has no directionality since each entrance, having a ground plan with an odd number of sides, is in front of a buttress. It too is an economic work, but this poorness of resources matches the formal ones. The cornice, which in the High Baroque is basic, has here been substituted by a thick wooden handrail that plays the same role.

Fig. 10.27. Chapel of the Church of the Assumption, in Priego de Córdoba, by Pedrajas (Escrig).

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Fig. 10.28. Former project for Saint Clare, in Turin, by Vittone (Norberg Schulz).

Fig. 10.29. Developed project for Saint Clare, in Turin (Norberg Schulz).

Obviously, both designs are previous to Vittone’s and in this case of similar dimension. But neither in the latter has got the right inner spatiality. Another of Vittone’s former works, but even more modest, is Saint Louis Gonzaga in Corteranzo (1740). Vittone practices Guarini’s concepts (Fig. 10.24). As in Vallinoto, he builds three bodies superimposed as

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in a pagoda and ending in a cupola. From the outside it can look like a new variation. But now, the chosen model is the Chapel of the Turin Shroud. The ground plan is triangular and the three transverse arches, instead of curving outward curve inward, stressing the triangular shape in which the resultant three niches correspond to the chapels and the walls hollowing is used as an access, placed in front of the altar and its

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Fig. 10.31. Saint Clare, in Bra, by Vittone (Wittcower).

Fig. 10.30. Saint Clare, in Vercelli, by Vittone (Norberg Schulz).

two side chapels. Again we find a clear axiality in ground plan and in elevation. The three bodies correspond firstly to the level of the pilasters and the columns ending in a powerful but repeatedly interrupted cornice, secondly to that of the transverse arches behind which are the light boxes and the pendentives, having only a window that crowns the entrance stressing the directionality, and finally to that of the dome, only one

in this case but not a simple one. He repeats the scheme of Fathers Somascos Church in Mesina, which he knows well (Fig. 5.39), but giving it more power and perforating it with six oculos instead of six large windows since it is less cambered. The huge cupola adds an additional amount of illumination. It cannot be said that the starred ribbings are the structural foundations of the dome since the cap works in a rather continuous way and is hemispherical. But the fact that the star points rest on the columns indicates a clarity in the transmission of forces that places this case far from the baroque temptation of contradicting the physical laws.

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Even when continuing unfinished works, Vittone showed a special skill. In Saint Bernardino in Chieri, of cruciform plan, he was able to place his typical light boxes to perforate the adjacent spaces. Apart from that, he has no special interest, though he initially had worked (in 1740) on a more expensive church placed in an urban area and tried, breaking the pendentives that we will see below (Fig. 10.25). The series of works that he created between 1740 and 1743 for the Order of Saint Clare, shows an endless formal investigation on a recurrent objective that is making the plan curves ascend in a curving way, intertwining these species of branches with the light filtered through hidden or concealed openings. This implies a unitary conception not evident from the outside since each body is hooped with a strong cornice. This capacity did not have continuers apart from some works closer to the Neoclassicism, as Souflot’s Saint Genevieve in Paris, dating from 1757 (Fig. 10.26), a work undoubtedly influenced by Vittone, though we cannot know how since his treatise was published three years later and the clearest precedent is Saint Paul's in London. Nevertheless, we have to consider that it was not finished until 1780, a year in which the text was already published. Because of its total conception of space, we look at the side chapel of the Church of the Assumption in Priego de Córdoba, from 1784, by Pedrajas (Fig. 10.27). More than the structure, it is the over-elaborate and dense decoration which plays the role of foliage of this vegetal dome, although the cornices are not radically dispensed with since they exist and curve forming a fake image of the plan. It is worth thinking that Vittone may have influenced it in some way, since the indirect illumination from several points of the building makes it share the same architectonic concept, a fact seldom appearing in Spanish architecture. The dome is similar to that of Sergio and Baco in Istanbul, ornamented with sixteen lobes alternatively cylindrical and convex, on them the windows are placed. Even in elevation the two levelled series of arches are reproduced with a Byzantine continuous gallery, following the scheme in Saint John Nepomuceno (Fig. 10.23).

Fig. 10.32. Present plans of Saint Clare, in Bra (information supplied by the city of Bra).

The light treatment is relatively conventional, though again we find the light boxes over the three chapels. In this case the decoration is simple but, nonetheless, we easily perceive that it is a late-baroque church.

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Saint Clare, in Turin, reproduced the hexagonal plan scheme and the same light treatment as that in Vallinoto, although in this case the dome has a single though staggered shell (Fig. 10.28). The final project has nothing to do with the rejected one (Fig. 10.29). Saint Clare in Vercelli tries again the hexagonal scheme (Fig. 10.30) with a curious development in which the side chapels are placed in an ambulatory, separated only by columns, and the dome does not rest in its vertical but in its exterior covering, bending the ribbings in their resting point forming purely

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Fig. 10.33. Inner view of Saint Clare, in Bra (Escrig).

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Fig. 10.34. Saint Mary of Plaza, by Vittone (Norberg Schulz).

decorative scrolls. This temple with concave hexagonal plan and ambulatory is a curiosity that cannot be found in any contemporary work. The most complex of the three is Saint Clare, in Bra. Its original project is extremely complicated as can be seen in his own drawings (Fig. 10.31), although the project later carried out includes some variations that do not distort the exterior look but lend it a more potbellied aspect (Fig. 10.32). Saint Clare, in Bra, is

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credited with being the best of his works, synthesising all his findings: the double shell connected as a light filter, the vertical ascension of the elements, free of a continuous planking, the conversion of the drum in a plan repetition and the total unity of the inner space (Fig. 10.33). Another group of churches in which he performs more experiments is that leading to the breaking of the pendentives that makes the transition from the plan to

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Fig. 10.36. Saint Croce, in Villanueva de Mondovi, by Vittone (Norberg Schulz).

Fig. 10.35. Inner view of Saint Mary of Plaza (Escrig).

Fig. 10.37. Inner view of Saint Croce (Escrig).

the dome. This allows octagonal domes without the inconvenience of a springing cornice for support.

are reached without pathologies appearing (Fig. 10.35).

Saint Mary of Plaza, from about 1750, is one of the examples of that breaking (Fig. 10.34). We see that on the four transverse arches, the superficial structure is interrupted by hollows. This is possible due to the ribbed domes and that is why spans of almost 20 m

In Saint Croce in Villanueva de Mondovi, he again planned with more success the same violation of architectonical laws, reaching the ideal of the vegetal mesh mentioned above (Fig. 10.36). It is an intelligent transition from the Greek cross plan to the octagonal drum (Fig. 10.37). In Saint Albert of Charity he repeated

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Fig. 10.38. Church of the Salzburg University, by Fischer von Erlach (Sedlmayr).

this, without adding anything to Saint Mary’s. In all these works he has renounced his previous findings: the double shell and the illumination effects and, although he had become formally more baroque, he had focused on the solid skeleton at the expense of intuition and veiling. In a way it is a step back for an architect to repeat the contemporary schemes forsaking his brilliant beginning. His later works are elegant but do not add anything. Vittone, who had been one of the great supports of the Guarinian movement, declared in those years that “the domes of the master are dark and difficult and not easy to cover”. What a surprise! In 1683 the Turks finally failed at the gates of Vienna

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and a project of regeneration on the basis of the Counter reform began, logically affecting architecture. Catholicism consolidated Europe thanks to the Habsburgs with its heart in Vienna, the old European capital that now needed to dress up. An architect formed in Italy under the direction of Fontana, Johan Bernhard Fischer von Erlach, contemporary of Juvara, assumed the direction of the new Austrian school, a prolific and particular school. In 1700, Fischer made a declaration of principles in the Salzburg University. We will not spend much time on that project too Italian (Fig. 10.38): outward convex very luminous façade, two towers in Borromini’s way, longitudinal plan and a high dome perforated in its sides. Fischer knows the Roman architecture of the High Baroque perfectly, he had learned a lot during his stay between 1660 and 1685, and takes basically Borromini’s and Bernini’s

Scenographical Architecture of the 18th Century

Fig. 10.41. Church of the Castle of Smirize, by Georg Dientzenhofer (Escrig).

Fig. 10.39. Church of Saint Lawrence, in Gabel (right) compared with Saint Lawrence in Turin (left) (Escrig).

Fig. 10.40. Pauline Abbey, in Oboriste, by Georg Dientzenhofer (Escrig).

Fig. 10.42. Gothic church of Karlov, in Prague (Kruban).

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Fig. 10.43. Inner view of Saint Nicolas of Malá Strana, in Prague (Escrig).

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Fig. 10.45a. Church of Saint Clare, in Eger. Fig. 10.45b. Church of Saint Margaret, in Prague (Escrig).

Fig. 10.44 Dientzenhofer’s project for Saint Nicolas of Malá Strana, in Prague (Norberg Schulz).

elliptical space as the element that gives form to the whole, though not in this particular project. In spite of his name, Lucas von Hildebrant was Genovese by birth. Fontana’s disciple too, he knew perfectly Guarini’s works because he had worked as an expert in fortifications in Piedmont until 1696. He was the other architect in charge of dressing up Vienna. His Belvedere Palace equals in magnificence the Schönbrunn Palace, both have a Versailles touch. His first work in Prague, the Church of Saint Lawrence in Gabel, from 1699, is a replica of Saint Lawrence’s in Turin (Fig. 10.39). The youngest of the Dientzenhofer brothers, Christoph, visited Turin in 1690, bringing some ideas that allowed him, along with Georg, to revolutionise the Czech architecture. The same year, 1700, indicates the start of two key pieces: the Pauline Abbey in Oboriste (Fig. 10.40) and the church of the castle of Smirize (Fig. 10.41), both belonging to the castle. They share one thing, a long plan that recalls a mixing between Saint Carlino (Fig. 5.6) and the Church of Propaganda of the Faith (Fig. 5.23), both by Borromini. The way of solving the vaults have changed, but not so much as it may seem. In the first case we can refer to the Immaculate Conception in Turin, by Guarini, not described in this text. The second case is a gothic inheritance that had much power in Bohemia. For instance, the octagonal

Fig. 10.46. Generation of Dientzenhofer’s vaults from a sphere (Escrig).

church of Karlov in Prague has a 1575 hemispheric ribbed cover that tries to be a replica of an older one (Fig. 10.42). Of all the buildings by the Dientzenhofer, the most successful, dating from as early as 1703, is Saint Nicolas of Malá Strana in Prague (Fig. 10.43), in which walls and waving vaults completely dissolve the form and soften the space. There are no longer groins but a curvilinear flow in which gravity does not appear to exist, seeming inside a cloud. Construction and painting are indissoluble, since the borderlines have been erased due to the perspective of the fresco paintings (Fig. 10.44). These brothers represent for Prague what Fischer and Hildebrandt did for Vienna, and helped to consolidate the capital of a new fiercely catholic European state. One of the main characteristics of Dientzenhofer's work is the extensive use of an elliptical vault plan to cover longitudinal spaces by superimposing modules. We

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Fig. 10.47. Composition of the Dientzenhofers' spherical vaults (Escrig).

Fig. 10.49. Church of the Monastery of Wallastatt, by Killian Dientzenhofer (Escrig).

Fig. 10.50. Church of Karlovy Vary, in Karlsbad, by Killian Dientzenhofer (Escrig).

Fig. 10.48. Adaptation of the system to Saint Nicolas (a), Saint Clare (b) and Saint Margaret (c) (Escrig).

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have already seen it in Saint Nicolas and are going to see it in Saint Clare in Eger (Fig. 10.45a) and Saint Margaret in Prague (Fig. 10.45b). It is curious that the apparent complex tracing is no such thing since all the vaults are portions of a sphere and can be constructed with a thread. Apart from this, it has a

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very favourable structural behaviour since the borders are always reinforced by thick ribs not visible from the interior. In Fig. 10.46 we can see the generation of Bohemian vaults that have the advantage of adapting to any proportion of length and width and, therefore being very narrow or very wide (Fig. 10.47). Fig. 10.48 shows the adaptation of this system to three works by Dientzenhofer: Saint Nicolas (a), Saint Clare (b) and Saint Margaret (c). Both brothers use the same procedure in opposition to Kilian, the son, who chose unitary spaces. Kilian Dientzenhofer and Baltazar Neuman were the most prolific and skilful of the XVIIIth century second generation of architects. Both of them used the Bohemian precedents and occasionally repeated the models of the brothers George and Cristophe.

Fig. 10.51. Vaulting usual system of Killian Dientzenhofer (Escrig).

The church of the Monastery of Wallastatt (Fig. 10.49), from 1723, or that of Karlovy Vary in Karlsbad (Fig. 10.50), from 1733, use elliptical domes. But Kilian does not feel comfortable with them. Many are the projects in which, as his ancestors did, he uses the spherical cap, basically supported by eight vertexes, regular or alternately spaced out (Fig. 10.51). With this solution he solves the covering of some of the best known churches: Saint John Nepomuceno in Prague, the Sanctuary of Nikov, Saint Adalbert of Pocaply, Saint John of the Rock and many more. In other cases he uses cylindrical forms, with even easier tracing. Another second generation architect, Dominique Zimmerman, uses the unitary elliptical form in a project that recalls strongly Juvara in Stupinigi (Fig. 10.10). The pilgrimage church in Steinhausen, from 1728, though previous is a more baroque version of Karlovy Vary (Fig. 10.52a). For a start, the number of divisions is ten not eight, the chapels have turned into ambulatories and the vault is a vegetal tangle on an ellipse with ten legs. The relatively sober aspect of the lower level contrasts with the motley look from the pilasters planking. Maybe it does not represent a structural challenge since its 25 x 12 m well buttressed expanse even goes with an almost flat cambering, but it implies a formal freedom that the author himself would exploit in other works (Fig. 10.52b).

Fig. 10.52a. Pilgrimage church of Steinhausen, by Zimmerman (Escrig).

We have mentioned among the first generation figures, Theodore Fischer, whose work in Vienna was influential all over Europe. He was productive in all the architectonic fields, including the archaeological one. He was a disciple of Bernini and Fontana and a friend of Juvara and Hildebrandt and knew Borromini’s work well. Back in Vienna and after some consolidation years, he clearly decides to go for the elliptical forms in his civil and religious works. His best known work is the church of Saint Charles Borromeo in Vienna (Fig. 10.53), from 1715, that in its

Fig. 10.52b. Volumes of the pilgrimage church of Steinhausen, by Zimmerman (Escrig).

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Fig. 10.53. Church of Saint Charles Borromeo, in Vienna, by Teodor Fischer von Erlach (Sedlmayr).

formal emphasis cannot get rid of the continuous cornices that isolate the different spaces. In fact, it does not add any structural innovation to the Vicoforte de Mondovi dome (Fig. 2.75) and is a very classic project, linked more to Bernini’s than to Borromini’s and agreeing with the French architecture. Even its size is not spectacular, though its high drum is in proportion the highest of elliptical form, which is not much when steel banding are perfectly calculated to absorb the horizontal thrusts. The highest point is reached by Baltazar Neuman, who managed to use with an absolute freedom the combination of elliptical forms that his predecessors had only been able to treat in isolated cases. In contrast to them, his knowledge of Italian architecture comes very late, since he does not do the classical trip of all the European architects until 1717. Pehaps that is why he was most influenced by his peers and decided to surpass them with his proposals. From 1727 he

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advanced with greater strides. In the Palace of Würzburg he tried his new systems in the splendid reception and dancing halls and in the chapel (1731-32) (Fig. 10.54), which in plan is to be the intersection of four ellipses and a vault, the tangency of three (Fig. 10.55). The spans are small (hardly 9 m.). In comparison with other palace chapels such as Versailles by Mansart, from 1689-1710, having 12 m (Fig. 10.56), or that of Mafra in Portugal by Ludovice (1717-33), even more classic and leaning toward the excess (Fig. 10.57), this work of Würzburg stands out because of its constructive modesty, its imagination and formal richness, and opens a new way of conceiving the spaces definition. From now on, these are trapped by some gigantic hands whose fingers are the pilasters that drive into the ground without any interruption. To make this possible the rat-trap bond vault was used, which is auto supporting with a minimum thickness and usually has a wooden

Scenographical Architecture of the 18th Century

Fig. 10.54. General plan of the Palace of Würzburg.

Fig. 10.55. Neuman’s project for the Palace of Würzburg chapel (Freeden).

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Fig. 10.59a. Project for the Sanctuary of Vierzhenheiling, by Baltasar Neuman (Freeden).

Fig. 10.56. Chapel of the Palace of Versailles, by Mansart (Escrig).

Fig. 10.57. Church of the Palace of Mafra, in Portugal, by Ludovice (Escrig).

Fig. 10.58. Outline of the Baltasar Neuman’s vaults (Escrig).

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Fig. 10.59b. Constructive axonometry of Vierzhenheiling (Norberg-Schulz).

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dustcover that isolates it from the inclement weather and overload, at the same time producing the fire protecting symbiosis of the delicate wooden roof (Fig. 10.58).

Fig. 10.60a. Main volumes of Vierzhenheiling (Escrig and Compan).

The Sanctuary of Vierzhenheiling is a clear example, since the vaults become autonomous from the walls and anchor themselves to the floor (Fig. 10.59a). Again we find a little decorated lower part and the vaults concentrating the filigrees. All the levels are simple: plinths, columns or pilasters with only planking or cornices on them and, from that point, the fingers that gather in the palm, a very painted vault (Fig. 10.59b).

Fig. 10.60b. Principal stresses of self-weight of Vierzhenheiling (Escrig and Compan).

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Fig. 10.60c. Original drawing of the project of Vierzhenheiling (Hansmann).

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Fig. 10.61b. Longitudinal section of Benedictine Church of Neresheim, by Baltasar Neuman (Escrig and Compan).

Fig. 10.61a. Benedictine Church of Neresheim, by Baltasar Neuman (Freeden). Fig. 10.61c. Volumes of the benedictine Church of Neresheim, by Baltasar Neuman (Escrig and Compan).

Fig. 10.61d. Main stresses due to self-weight of the benedictine Church of Neresheim, by Baltasar Neuman (Escrig and Compan).

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It is modest and poor but extremely effective architecture. When walking along the wooden skeleton that makes the roof slope, you can see the bare brick of the extrados of those elastic shells made of mortar and ceramics (Fig. 10.60a). When observed from below, an immense formal, ornamental and colour richness is suspected that otherwise has a load capacity (Fig 10.60b). Figure 10.60c shows the precision in the previous design of military engineers and architects.

The Benedictine church of Neresheim is his best known work (1749). The rosary of tangent ellipses with its huge central dome on eight autonomous columns turn it into a spatial and constructive prodigy (Fig. 10.61). In this case, the pristine white interior, contrasting with the fresco paintings in the vaults, offers an unexpected baroque contrast. Neuman’s civil work is impressive too. In the Palace of Würzburg he created some singular spaces of large structural value. The stairs vault, a rectangle of 30 x 20 m. decorated with fresco paintings by Tiepolo, is the biggest of its kind (Fig. 10.62). Hildebrandt was so envious of him because of this skiffed vault that he said it would collapse if someone hung from it. Nevertheless, during the Second World War the whole palace was bombed, and this vault was the only one that kept intact. The other rooms were smaller but no less bold (Fig. 10.63). The superior vaults are made of plasterwork hanging from a wooden skeleton, and the inferior ones are auto supporting.

Fig. 10.62. Vault of the main staircase in the Palace of Würzburg, by Baltasar Neuman (Freeden).

To end with Central European architecture, we want to mention the Church of Our Lady of Dresden, built during the years 1726 to 1743 by the architect George Bähr, it has more than its structural value because of the literature. Having been totally destroyed in the last world war and being in a process reconstruction, it provides us with a lot of information. Fig. 10.64 shows the complex vertical section, whereas Fig. 10.65, the horizontal sections at different levels. What we want to stand out is the bell shape tracing of the dome set (Fig. 10.66), justified by the need to introduce buttresses to balance the strong thrusts in the base (Fig. 10.67). Fig. 10.68 shows the relative scale in respect of Saint Peter’s in the Vatican, and his characteristic way of working, whereas Fig. 10.69 illustrates the stresses obtained by means of a calculation by finite elements. Despite the existence of steel hoops (Fig. 10.70), it underwent an important pathology before the bombing (Fig. 10.71). We have not mentioned in this chapter the English, French or Iberian baroque. The first two have too classic an aspect and herald later events of the XVIIIth century. As for the latter, however interesting it may be, it gets exhausted in the decoration. Even the best Spanish architect of the time, Leonardo de Figueroa, is far away from the typological research. His church of Saint Louis of French has much subtlety, but its scale is that of a reliquary (Fig. 10.72).

Fig. 10.63. Main rooms in the Palace of Würzburg, by Baltasar Neuman (Freeden).

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Fig. 10.66. Contemporary engraving of the Church of Our Lady, in Dresden (Jager and Brebbia).

Fig. 10.64. Section of the Church of Our Lady, in Dresden, by George Bähr (Jager and Brebbia).

Fig. 10.65. Horizontal sections in different levels of the Church of Our Lady, in Dresden (Jager and Brebbia).

Fig. 10.67. Bell-shaped tracing of the vault support, to balance the horizontal thrusts (Jager and Brebbia).

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Fig. 10.70. Old steel hoops in the vault of Our Lady of Dresden (Jager and Brebbia). Fig. 10.68. A comparison between the shapes and the descending loads of Saint Peter’s and Our Lady of Dresden (Jager and Brebbia).

Fig. 10.69. Analysis by Finite Elements and stresses obtained from the rebuilding project of Our Lady of Dresden after the bombings (Jager and Brebbia).

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Fig. 10.71. Pathology of Our Lady of Dresden prior to its destruction (Jager and Brebbia).

Fig. 10.72. Church of Saint Louis, in Seville, by Leonardo de Figueroa (Bonet Correa).

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REFERENCES OF CHAPTER 10

1. BONET CORREA, A. "Andalucía Barroca". Ed. Polígrafa, S.A. 2. BONET CORREA, A. "Filipo Juvara". Electa, Milan. 3. CASTEX, J. "Renacimiento, Barroco y Clasicismo. Historia de la Arquitectura 1420-1720". Akal, Madrid. 4. CHARPENAT, P. "Baroque. Italie et Europa Centrale". Office du livre. 5. COMPAN, V. , ESCRIG, F. & SANCHEZ, J. "The Shell structures of the Baroque". STREMA 2003, WIT Press, Southampton, pp. 65-74. 6. ESCRIG, F. “Towers and Domes in Architecture”. WIT Press, Southampton. 7. FRANZ, E. " Räume, die im Sehen enstehen". Ed. Tertium, Stuttgart. 8. FREEDEN, M.H. von. “Baltasar Neuman”. Deutcher Kunstverlag, Munchen. 9. HANSMANN, W. "Balthasar Neuman". Dumont. 10.HRUBAN, I. “Historic Domes from Czechoslovakia”.

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Domes from Antiquity to the Present, IASS Symposium 1988, Istanbul. 11. MEEK, H.A. “Guarino Guarini”. Electa, Milan. 12.MULLER, W. “Von Guarini bis Balthasar Neumann”. Michael Imhof Verlag, Petersberg. 13.NORBERG-SCHULZ, Chr. “Arquitectura Barroca tardía y Rococó”.Aguilar, Madrid. 14.NORBERT-SCHULZ, Chr. “Kilian Ignaz Dientzenhofer e il Barroco Boemo”. Officina Edizioni, Rome. 15.POMER, R. “Eighteenth-Century Architecture in Piedmont”. University of London Press Ltd, London. 16.SEDLMAYR,H. “Johan Bernard Fischer von Erlach arquitecto”. Electa, Milán. 17.STIERLIN, H. “Iberian-American Baroque”. Taschen, Lausane. 18.TOMAN R. Ed. “El Barroco". Könemann, Colonia. 19.WITTKOVER, R. “Arte y Arquitectura en Italia 1600-1750”. Catedra, Madrid.

The Virtual Architecture of the Renaissance and the Baroque

Chapter 11. THE VIRTUAL ARCHITECTURE OF THE RENAISSANCE AND THE BAROQUE

In the main altar of Saint Mary near Saint Satire in Milan (1478), Donato Bramante did a brilliant exercise of nave lengthening by means of a perspective artifice (Fig. 11.1). It consisted on prolonging the coffered barrel vault with a vanishing point placed at a very studied height that was not that of the cornice. From the front, you feel a sensation of depth hardly denied by the physical reality (Fig. 11.2). When drawing or painting, all the great masters used their researches in perspective, whereby they could recreate large buildings and gigantic structures independently of their physical construction. Piero della Francesca (Fig. 11.3), Albert Durero (Fig. 11.4), Leonardo da Vinci (Fig. 11.5), Rafael (Fig. 11.6) and other anonymous artists turned the quattrocento into a universal laboratory. We have already seen in chapter 9 how Michelangelo virtually rebuilt the architecture of the Sistine Chapel ceiling (Fig. 9.3) with a more than decorative objective, since in his painting there was a whole architectonic programme, apart from philosophical and other concepts. The Sistine Chapel inaugurates too another kind of perspective, the corrected cylindrical, instead of the conical resulting from the applying of the theoretical principles. This allows the observer to move without leaving the focal references. Rafael though, had a vocation for architecture that went beyond his profession of painter (Fig. 11.7). Palladio had a clear awareness of the spectators deception in his theatre sceneries. His Vicenza theatre exploited in depth these techniques (Fig. 11.8) that Sergio later interpreted even as states of mind (Fig. 11.9). The XVIth century was less fruitful since there was no longer the worry about the architectonic background in the painting. It was after the Council of Trento, when the pedagogical and moralising function was again put on the representation, that the virtual architecture became important again. For this allowed grandiose images with a very low budget. Pietro de Cortona , in the first half of the XVIIth century, best represents these tendencies. Architect and painter, he managed to combine both arts in his

Fig. 11.1. Main altar of Saint Mary near Saint Satire in Milan, by Bramante.

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Fig. 11.4. Treatise of perspective by Durero. Print.

Fig. 11.2. Illusory view of the above altar.

Fig. 11.5. Sketch for the Adoration of the Magi, by Leonardo.

Fig. 11.3. Perspective by Piero della Francesca.

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Fig. 11.6. The Virgin Mary Nuptials, by Raphael.

The Virtual Architecture of the Renaissance and the Baroque

Fig. 11.7. The School of Athens, by Raphael.

Fig. 11.10. Glorification of the Pope Urban VIII, by Pietro di Cortona.

Fig. 11.8. Section of the Theatre of Vicenza, by Palladio.

Fig. 11.9. Theatre set by Serlio.

designs. In the glorification of Urban VIII's papacy, he developed a unitary tracing that made the walls higher and the ceiling farther (Fig. 11.10). Domingo Canuti is, with his Apotheosis of Saint Domingo, a complex example in the second half of the century (Fig. 11.11).

Fig. 11.11. Apotheosis of Saint Domingo, by Domingo Canuti.

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Fig. 11.12. Perspective by Colona.

Fig. 11.13. Perspective by Ferrari.

Fig. 11.14. Ceiling of the Church of Saint Ignacio, in Rome, by Andrea del Pozo.

The list of examples is endless. Colona (Fig. 11.12) and Ferrari (Fig. 11.13) in addition introduce fantasy . Andrea del Pozo, a good architect and clear-sighted enough to interpret the role that painting could play in the space definition perhaps best systematises the complex perspective systems that even nowadays amaze us at the multiple vanishing points and potential vision from any position. The ceiling of the Church of Saint Ignacio in Rome not only has a focus but contains a perfect definition of the orders and of the wall complex, which gets longer (Fig. 11.14).

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It is in the Church of Il Gesu, by Vignola, where several architects compete by experimenting with the virtual one. The proposal by Carlo Rainaldi basically is close to that proposed by Bramante two hundred years before. The successive spans of squinched or spherical vaults, we cannot identify them with precision, contrast excessively with the severity of the main nave (Fig. 11.15). This explains why it was rejected since, as seen in the assembly, it was unbelievable (Fig. 11.16). Although several of the projects by Andrea del Pozo were better studied, they were not built. The most similar to the executed work is that shown in Fig. 11.17

The Virtual Architecture of the Renaissance and the Baroque

Fig. 11.15. Proposal by Rainaldi for the apse of the Church of Il Gesu, in Rome.

Fig. 11.17. Project by Andrea del Pozo for the apse of the Church of Il Gesu, in Rome (Defeo and Martinelli).

Fig. 11.16. Assembly of the mentioned proposal by Rainaldi.

Fig. 11.18. Section of the mentioned project scenery (Defeo and Martinelli).

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Fig. 11.19. Present aspect, with the decoration already finished, of the Church of Il Gesu apse, in Rome (Defeo and Martinelli).

Fig. 11.21. Breaking down into its elements of the alternative project by Andrea del Pozo (Defeo and Martinelli).

Fig. 11.20. Alternative project proposed by Andrea del Pozo (Defeo and Martinelli).

Fig. 11.22. Another alternative project by Andrea del Pozo for the Church of Il Gesu (Defeo and Martinelli).

which, in fact, is the less virtual (Fig. 11.18). Fig. 11.19 shows a picture of the present state. Other designs for the same purpose, as that seen in Fig. 11.20, look too insipid. Fig. 11.21 shows its decomposition. In contrast, that of Fig. 11.22 is too complex, as can be seen in the Fig. 11.23 photomontage.

The great architect of the XVIIth century was Antonio Bibiena, whose constructed work has a relative interest in contrast with his paintings that are magnificent. Fig. 11.24 shows the perforated dome of the Church of the Trinity in Pozsony, whereas Fig. 11.25 shows a design to make the wall of a room deeper. His perspectives

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The Virtual Architecture of the Renaissance and the Baroque

Fig. 11.25. Perspective of a room by Bibiena.

Fig. 11.23. Photomontage for the second alternative project (Defeo and Martinelli).

Fig. 11.26. Perspective at a 45º rotation, by Fernando Bibiena.

Fig. 11.24. Dome of the Church of the Trinity, in Pozsony, by Antonio Bibiena.

at 45º form part, with those by his brother Fernando, of a valuable collection that became widely known (Fig. 11.26). His family maintained the tradition in the following century (Figs. 11.27 to 11.29). The proposals by Fernando Bibiena and Bufagnotti for the vaults in the XVIIth century, inspired numerous roofs (Fig. 11.30), as well as those by Colonna (Fig. 11.32).

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Fig. 11.29. Interior with staircases by Francesco Bibiena.

Fig. 11.27. Gran imperial logia by Fernando Bibiena.

Fig. 11.30. Composition in perspective by Fernando Bibiena and Bufagnotti.

Fig. 11.28. Gran atrium by Francesco Bibiena.

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Really interesting are those pieces that introduce non existent domes in squinched domes. Fig. 11.33 shows a proposal by Minozzi. In Fig. 11.34 can be seen drawings by Schenk from 1728 and in Fig. 11.35, Carboni’s. No doubt that Batista Piranessi is the best known of all the architecture draftsmen, but his work

The Virtual Architecture of the Renaissance and the Baroque

Fig. 11.31. Vanishing perspective for a ceiling, by Bibiena.

Fig. 11.32. Proposal for a ceiling by Colonna.

Fig. 11.34. Proposals for a ceiling by Schenk.

was never used to widen the spaces with fake images. As an architect he was mediocre and we have already cited the recreation of his project for Saint John of Letran, based on Borromini’s project (Fig. 9.16b). As for its physical application to XVIIIth century architecture, the results are fruitful. Let us remember among the works mentioned in previous chapters, Stupinigi’s decoration by Juvara (Fig. 10.11), See also Steinhausen’s by Zimmerman (Fig. 11.36), Steigerwald’s by Neuman (Fig. 11.37) and Saint Louis’ by Leonardo de Figueroa (Fig. 11.38).

Fig. 11.33. Proposal for a ceiling by Minozzi.

This chapter cannot really be considered as structural in a wide sense, though without a minimum knowledge of construction none of these draftsmen or painters could have produced what they did. Paper architecture is a term whose meaning we know well in this century. Undoubtedly, the Baroque adds a new dimension to architecture not to be seen again until the arrival of cinemas.

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Fig. 11.36. Decorated ceiling in Steinhausen, by Zimmermann.

Fig. 11.35 Proposal for a ceiling by Carboni.

Fig. 11.37. Illusory ceiling in Steigerwald, by Neuman.

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Fig. 11.38. Illusory decoration in Saint Louis of the French, by Leonardo de Figueroa (Bonet Correa).

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REFERENCES OF CHAPTER 11

1. ADAM, R. "Drawings and Imagination". A.A. Tait. Q72 Adam 6. Cambridge Studies in the History of Architecture. 2. BEAUMONT, M.A. "Eighteenth-Century Scenic and Architectural Design. Drawings by the Galli Bibiena Family". Art Services International, Alexandria, Virginia.

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3. CONTARDI, B. & CURCIO, G. "In Urbe Architectus: Modelli, disegni, misuri. La profesione dell´Architetto". Rome, 1680-1750. 4. DEFEO, V. & MARTINELLI,V. "Andrea Pozzo". Electa, Milan. 5. DEFEO, V. "Andrea Pozzo: Architettura e illusione". Roma Oficina Edición. 6. GALLI BIBIENA, G. "Architectural and Perspective Designs". Dover Publications, Inc., New York.

Digital Architecture Edited by: A. ALI, University of Seoul, Korea and C. A. BREBBIA, Wessex Institute of Technology, UK Digital Architecture is a particularly dynamic field that is developing through the work of architecture schools, architects, software developers, researchers, technology, users, and society alike. Featuring papers from the First International Conference on Digital Architecture, this book will be of interest to professional and academic architects involved in the creation of new architectural forms, as well as those colleagues working in the development of new computer codes of engineers, including those working in structural, environmental, aerodynamic fields and others actively supporting advances in digital architecture. Expert contributions encompass topic areas such as: Database Management Systems for Design and Construction; Design Methods, Processes and Creativity; Digital Design, Representation and Visualization; Form and Fabric; Computer Integrated Construction and Manufacturing; Human-Machine Interaction; Connecting the Physical and the Virtual Worlds; Knowledge Based Design and Generative Systems; Linking Training, Research and Practice; Web Design Analysis; the Digital Studio; Urban Simulation; Virtual Architecture and Virtual Reality; Collaborative Design; Social Aspects. ISBN: 1-84564-047-0 2006 apx 400pp apx £145.00/US$265.00/€217.50

Structural Studies, Repairs and Maintenance of Heritage Architecture IX Edited by: C. A. BREBBIA, Wessex Institute of Technology, UK and A. TORPIANO, University of Malta, Malta This book contains most of the papers presented at the Ninth International Conference on Structural Studies, Repairs and Maintenance of Heritage Architecture. The Conference was held in Malta, a state smaller than many of the cities that this Conference has visited, and yet that is packed, in the full meaning of the word, with a history of heritage architecture that spans nearly six millennia - as far as we currently know! The islands of Malta have limited material resources, in fact, only one - limestone, and a rather soft one at that. However, out of this resource, our ancestor builders have fashioned the habitat for their lives, as these unfolded and changed over the centuries. The problems and efforts that are being made to repair, restore, conserve and protect such limestone architectural heritage are considerable and mirror similar problems faced by other architects, engineers, curators, art historians, surveyors and archaeologists in other countries throughout the world. The papers featured are from specialists throughout the world and divided into the following topics: Heritage architecture and historical aspects; Structural issues; Seismic behaviour and vibrations; Seismic vulnerability analysis of historic centres in Italy; Material characterisation; Protection and preservation; Maintenance; Surveying and monitoring; Simulation modelling; and Case studies. Series: Advances in Architecture Vol 20 ISBN: 1-84564-021-7 2005 672pp £235.00/US$376.00/€352.50

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Maritime Heritage and Modern Ports Edited by: R. MARCET I BARBE, Maritime Museum, Spain, C. A. BREBBIA, Wessex Institute of Technology, UK and J. OLIVELLA, Universitat Politecnica de Catalunya, Spain This book contains papers presented at two meetings with many shared interests - the Second International Conference on Maritime Heritage and the Fourth International Conference on Maritime Engineering The Second International Maritime Heritage Conference brought together scholars and professionals from a variety of areas. In addition to scientific advances, the contributions included in this volume discuss the future of historical harbours, dockyards and other similar maritime structures in today’s world, as well as the function of historical vessels and their heritage value. The role of development schemes and the relationship between tourism and the preservation of maritime heritage is also covered. The papers from the Fourth International Conference on Maritime Engineering, Ports and Waterways deal with topics such as port management, the integration of transport aspects, navigation, ship operation and multimode transport, information systems for ports and shipping, marine engineering works, hydrodynamic aspects, the construction and design of ports and marinas, and the development of ports and coastal areas. Emphasis is placed on the importance of the transport maritime mode in development and the requirements of making port operation more efficient, safe and productive. Series: Advances in Architecture Vol 19 ISBN: 1-84564-010-1 2005 512pp £179.00/US$286.00/€268.50

Earth Construction Handbook The Building Material Earth in Modern Architecture G. MINKE, Director of the Building Research Institute, Kassel University, Germany “…a good introduction to earth as a viable building material….well written and ordered in a way that makes its content accessible to those with limited scientific and technical knowledge. The reader’s understanding of the subject is supported by the many useful diagrams, tables and photographs.” JOURNAL OF ARCHITECTURAL CONSERVATION “...interesting and well constructed.” E-STREAMS Refined, updated and expanded for English speaking readers from the author’s bestselling Lehmbau-Handbuch (1994), this book is unique in providing a survey of applications and construction techniques for a material which is naturally available and easy to use with even basic craft skills, and produces hardly any environmental waste. The information given can be practically applied by engineers, architects, builders, planners, craftsmen and laymen who wish to construct cost-effective buildings which provide a healthy, balanced indoor climate. Partial Contents: Properties of Earth as a Building Material; Rammed Earth Work; Earthblock Work; Large Blocks and Prefabricated Panels; Loam Plasters; Weather Protection of Loam Surfaces; Repair of Loam Components; Designs of Particular Building Elements. Series: Advances in Architecture, Vol 10 ISBN: 1-85312-805-8 2000 216pp b/w diagrams & photographs £48.00/US$76.00/€72.00

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Structural Design of Retractable Roof Structures Editor: K. ISHII, International Association for Shell and Spatial Structures Presenting state-of-the-art data, design guidelines and recommendations for retractable roof structures, this book is based on the findings of a working group established by the International Association of Shell and Spatial Structures (IASS). International in perspective, it contains discussion of two kinds of system: 1) Non-collapsible rigid frame type structures with rigid or flexible material stretched between frames and, 2) folding membrane types such as tents and pneumatics. Series: Advances in Architecture, Vol 5 ISBN: 1-85312-619-5 2000 208pp US$148.00/€142.50

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The Conservation and Structural Restoration of Architectural Heritage Theory and Practice

Maritime Heritage

G. CROCI, University of Rome ‘La Sapienza’, Italy

Editors: C.A. BREBBIA, Wessex Institute of Technology, UK and T. GAMBIN, University of Malta, Malta

“The book should be seen and known about by all engineers and architects who are developing their work in the field.” THE STRUCTURAL ENGINEER

Papers from the First International Conference on Maritime Heritage. Topics covered include: Cultural Heritage Issues; Underwater Heritage; Historic Ports; Maritime History; and Ship Preservation and Ship Wrecks. Series: Advances in Architecture, Vol 15 ISBN: 1-85312-964-X 2003 212pp £85.00/ US$136.00/€127.50

“...instructive and fascinating.... The excitement and challenges of preserving and stabilizing historic buildings is captured by this very readable book.” JOURNAL OF ARCHITECTURAL CONSERVATION

Describing the evolution of towers and domes from a structural viewpoint, this highly illustrated book is written as two essays running parallel, one textual, the other graphic. Series: Advances in Architecture, Vol 4

Designed for use by all professionals involved or interested in the preservation of monuments, the purpose of this book is to contribute to the development of new approaches in the area. Many of the examples examined, including the Colosseum, the Tower of Pisa and the Pyramid of Chephren, are the result of work carried out during Giorgio Croci’s distinguished career. Featuring numerous black and white photographs and illustrations by the author, the text is divided into two main sections entitled The Scientific Approach to the Study of Architectural Heritage and Structural Analysis of Masonry Buildings. Series: Advances in Architecture, Vol 1

ISBN: 1-85312-437-0 1998 120pp US$95.00/€88.50

ISBN: 1-85312-482-6 1998 272pp US$237.00/€222.00

Towers and Domes F. ESCRIG, University of Sevilla, Spain

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Structural Studies, Repairs and Maintenance of Heritage Architecture VIII

Structural Studies, Repairs and Maintenance of Historical Buildings VII

Editor: C.A. BREBBIA, Wessex Institute of Technology, UK

Editor: C.A. BREBBIA, Wessex Institute of Technology, UK

This volume features papers from the eighth international conference in this respected series. Over 80 papers are included and these cover topics such as: Historical and Architectural Aspects; Deterioration, Protection and Evaluation of Materials; Simulation and Modelling; Structural Issues; Prevention of Structural Damage; Seismic Behaviour; Case Studies; Maintenance and Repairs; Material Problems; and Timber Constructions. Contributions to two special sessions on The Structural Conservation of the Archaeological Heritage of Italy and Long Term Behaviour of Masonry Structures: Learning from Failures, are also featured. Series: Advances in Architecture, Vol 16

“...the book is well suited for the bookshelf of the structural engineer….very scientific and well compiled and has some authoritative and worthwhile conclusions on many of the topics that have been under investigation. This book is also seen as a valuable aid and source of reference to those engaged in laboratory and research work on the conservation and care of historic buildings.” BUILDING ENGINEER

ISBN: 1-85312-968-2 2003 864pp £259.00/ US$409.00/€388.50

The proceedings of the Seventh International Conference on Structural Studies, Repairs and Maintenance of Historical Buildings. Series: Advances in Architecture, Vol 13 ISBN: 1-85312-869-4 2001 736pp £229.00/ US$355.00/€343.50

The Revival of Dresden

Historical Buildings of Iran

Editors: W. JÄGER, Technical University of Dresden, Germany and C.A. BREBBIA, Wessex Institute of Technology, UK

Their Architecture and Structure

In 1945 the ancient City of Dresden was destroyed by massive bombardments and much of its rich architectural heritage appeared to have been obliterated forever. Over the last half-century, however, Dresden has been lovingly reconstructed with the active collaboration of its citizens. This process, now culminating in the rebuilding of the Frauenkirche (the Church of Our Lady) is documented in this unique book. Partial Contents: THE REVIVAL OF THE CITY: The Contribution of Preservationists to the Reconstruction of the Semper Opera House; Restoration of the Castle in Dresden; The Reconstruction of Taschenberg Palace; The Conservation of the Neustadt District as Part of the Cultural Cityscape. THE FRAUENKIRCHE: The Citizens’ Initiative to Promote the Rebuilding; A Construction of Stone and Iron - Structural Concept for Reconstruction of the Dresden Frauenkirche; Structural Proof-Checking Using a Complete 3D FE-Model. Series: Advances in Architecture, Vol 7 ISBN: 1-85312-787-6 2000 272pp US$159.00/€145.50

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M.M. HEJAZI, Queen Mary and Westfield College, University of London, UK The first authoritative work to investigate the historical buildings of Iran from the perspective of structural engineering. Series: Advances in Architecture, Vol 2 ISBN: 1-85312-484-2 1997 168pp US$99.00/€100.50

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