A Literary and Structural Analysis of the First Dome on Justinian's Hagia Sophia, Constantinople Author(s): Rabun Taylor Source: Journal of the Society of Architectural Historians, Vol. 55, No. 1 (Mar., 1996), pp. 66- 78 Published by: University of California Press on behalf of the Society of Architectural Historians Stable URL: http://www.jstor.org/stable/991056 . Accessed: 20/11/2013 11:29

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This content downloaded from 130.58.65.10 on Wed, 20 Nov 2013 11:29:22 AM All use subject to JSTOR Terms and Conditions A Literary and StructuralAnalysis of the First Dome on Justinian'sHagia Sophia, Constantinople

essentials is similar to the surviving dome, only shallower. R. L. Rabun Taylor, Universityof Minnesota Van Nice even went so far as to claim that "the original T he first dome of Hagia Sophia in Constantinople, perhaps structural scheme was... intrinsically so unalterable that all the greatest structural and artistic innovation in Justini- later repairs were obliged essentially to reduplicate the forms an's church, is lost to us forever. Its precise shape and size are that had fallen. Thus, although reconstruction brought changes not recorded in the written or visual records; nor does an in detail, the principles at work were affected only in a matter of approximation of it survive in architectural filiations. Com- degree."3 This article offers a respectful challenge to Van Nice's pleted sometime in 537 C.E., the dome lasted just over twenty assumption. Whereas the existing dome is fenestrated and years before a series of earthquakes in 557 led to the collapse of springs directly from the marble cornice resting atop the main the eastern main arch in May 558. Deprived of this support, arches, a close reading of Procopius, who offers the most dome portions of the dome and eastern semidome fell with the arch, reliable eyewitness description, suggests that the original and the rest of the dome was cleared away for rebuilding. In his had no windows, and instead rested upon a fenestrated drum. ekphrasiswritten for the second consecration of the building in 563, Paul the Silentiary describes the collapse this way: THE MAIN STRUCTURE AND ITS LIMITS To attempt a reconstruction of the early dome, one must turn Now the wondrous curve of the half-sphere, although resting on first to the information inherent in the present building.4 The powerfulfoundations, collapsed and threwdown the entire precinctof following describes the dome and the primary structural com- the sacred house.... Yet, the broad-breastedfane did not sink to the ponents supporting it and cites some of the structural move- foundations... but the curve of the eastern arch slipped off and a ments that have taken place over the years [Figure2]. portionof the domewas mingled with the dust:part of it layon the floor, Of a broad, rectangular basilican plan, Hagia Sophia is and part-a wonderto behold hung in mid-airas if unsupported.... oriented roughly on an east-west axis. The crown of the present feet in According to the sixth-century historians Procopius and dome (A), which is just over 100 Byzantine diameter, floor.5 Four main Agathias, the first dome was an object of reverential astonish- hangs 178.3 feet (55.6 m) above the piers (B), define the ment. Apparently Justinian's contemporaries considered the made mostly of limestone and greenstone ashlars, of floor that lies beneath replacement dome-large parts of which survive in today's corers of the central 100-foot square dome-a less subtle achievement, admirable in its own right the dome. They rise 74.17 feet (23.14 m)6 and are spanned by brick which are bound but conveying less of the former magic. Agathias remarked that four thick semicircular arches of (C), at 133 feet "it did not strike spectators with as much amazement as before, together by brick pendentives (D). These culminate blocks but it was far more securely set up." This testimony must be (41.5 m) in a somewhat deformed circle of flat marble out several feet taken seriously, since Agathias is likely to have seen both domes upon which the dome rests (E). The blocks jut a cornice used as an inner personally.2 into the central space, forming The current dome is justly famous for its subtle visual effects walkway around the dome's base. of [Figure 1], and so one cannot fail to be intrigued by these brief The main east and west arches serve as the terminations full reports of lost grandeur. A number of scholars have ventured to the two main semidomes (F) which, being roughly quarter- surface radius than the main speculate on the shape of the original dome, but few have spheres, have a slightly smaller the nave to its full approached the problem in a systematic way, synthesizing the dome. The semidomes extend nearly length, main and two literary testimony and structural possibilities to arrive at a and are each supported by the piers secondary reasonable reconstruction of this ephemeral experiment by piers toward each end of the nave (G). The semidomes and east-west buttresses to the Justinian's master architects, Anthemius ofTralles and Isidorus secondary piers serve as the principal of Miletus. All have been satisfied to envision a dome that in its dome, main arches, and main piers.7 To the north and south,

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FIGURE2: Isometriccutaway view of HagiaSophia as it is today (modifiedfrom Mainstone,Hagia Sophia). The dome (A) rests upon the cornice (E), which forms a ringat the top of the pendentives (D). The main arches (C) springfrom massive stone piers (B), which rise from the corners of the central I00-foot square. The secondary piers (G) help to supportthe semidomes (F). Mainstoneshows that these latterelements effectively buttressthe dome and the east and west main arches. The buttresses to the north and south (H) have been somewhat less successfulin counteringthe lateralthrusts of the dome and main arches. external buttresses (H), rising nearly to the height of the main remainder of the first dome and start afresh, attacking the arch crowns, are joined by arches and walls to the main piers structural problem at the level of the arches. Agathias provides and the superstructure above them. a few interesting facts about the rebuilding: The present dome, parts of which have survived for 1,400 years, rises 48 feet (15.0 m) from the level of the upper cornice, SinceAnthemius had long been dead, Isidorethe youngerand the other just slightly short of a hemisphere.8 It is made of brick and engineers reviewed among themselves the former design and, by pozzolanic mortar. Anchored to the cornice, and thus indirectly referenceto what had remained,they judged the part that had fallen to the arches, it is pierced at the base by forty arched windows. down, i.e., its natureand its faults.They left the east and west archesas Between the windows thick radial ribs rise to the crown; the theywere in theirformer places, ? but in the case of the northand south webs, well integrated with the ribs, are somewhat recessed, with ones they extended inwardthat part of the constructionwhich lies on a an average thickness of about 2 /2 feet.9 On the outside, the ribs curveand graduallyincreased its width so as to make them [the north broaden into equally spaced spurs extending out about 7 feet, and south arches]agree more closelywith the others and observethe which serve as radial buttresses for the dome. harmony of equal sides. In this way they were able to reduce the Isidorus the Younger, nephew of one of the original archi- unevennessof the void and to gain a littleon the extent of the space,i.e., tects, designed the second dome. He decided to demolish the that part of it which produceda rectangularfigure. Upon these [new]

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This content downloaded from 130.58.65.10 on Wed, 20 Nov 2013 11:29:22 AM All use subject to JSTOR Terms and Conditions archesthey set up once againthat circle or hemisphere(or whatever else and 559-560, a couple of years after the collapse. Since the they call it) which dominatesthe centre of the building.As a result,the second dome was not completed until 562, there is no question dome naturallybecame more even and well-curved,conforming alto- that the dome Procopius described was the first one. But was he getherto the [correctgeometrical] figure. It wasnarrower and steeperso writing from direct observation in 554, or from memory in 560, thatit did not strikespectators with as muchamazement as before,but it when the remnants of the old dome had been demolished and wasfar more securelyset up. ' construction of the new dome was well under way? The answer may have a bearing on the precision of his description.17 The most pronounced distortions in the building then, as A number of scholars endorse the earlier date, arguing that now, were in the outward leaning of the northeastern and even a panegyric could not ignore so monumental an event as a southeastern main piers caused by spreading of the eastern collapse. Cyril Mango's recent assessment points out that, in arch. Similar distortions are visible to the west. Spreading The Buildings 1.1.69, Procopius ascribes to Justinian's genius began immediately after the arches were built. Left alone, it the completion of the very arch that collapsed in 558.18 This is would have continued at a steadily declining rate until the reason enough to accept 554 as the year of composition, as mortar dried. But when the first dome was added, its weight Justinian surely would not have allowed such an indiscretion compounded the spreading until the collapse, by which time after the collapse. But there are broader arguments for the the central "square" at the tops of the arches had become a earlier date as well. "Procopius'work is a celebration of imperial rectangle, gaining several feet on its north-south axis over its glory," Averil Cameron writes-"relevant enough in 554 when relatively stable east-west dimensions.12 This concerned the Italy had just been finally won, and when a good part of the younger Isidorus enough so that once he had demolished the ambitious building programme in Africa had just been carried remainder of the old dome and repaired the eastern arch, he out, but very out of place in 559 when the darkness of plots and thickened the outward-leaning north and south arches toward disillusion was settling round the aged Justinian."19 the crown, bringing their inside faces nearer to vertical, so that Procopius's description of the dome from inside Hagia the rectangle upon which he was to build would be closer to a Sophia is not in itself precise or detailed enough to justify the square. 13 conclusion that he is writing from direct observation. But his By examining the written descriptions and the building use of the present tense to describe the glories of the great itself, Rowland Mainstone has traced some of the inherent dome would have seemed gratuitous hypocrisy in 559 or 560, weaknesses in the building of 537.14 According to his calcula- when the growing ranks of Justinian's local detractors were tions, the weight and lateral thrusts of the first dome upon the faced daily with the ruined profile of Hagia Sophia. Describing arches were not in themselves manifestly excessive. Nor were finished buildings as if they are in the process of construction is the arches directly at fault. The Achilles' heel of the structure "a standard ekphrastic technique," one scholar claims. But no then, as now, he believes, was the insufficient buttressing to the ekphrastic poet to my knowledge wrote a paean to a partly north and south of the main piers.15 As we shall see, Main- destroyed building-much less to a building that he knew stone's analysis may underestimate the weight and instability of would look different when reconstructed, and thus render the the first dome. old description obsolete. Common sense must prevail over the arguments for the later date, which depend largely on the PROCOPIUS ON THE FIRST DOME evidence of a single reference in a chronology written centuries Every study of the original form of Justinian's Hagia Sophia after the fact.20 must inevitably take stock of Procopius's description of the It is well to be mindful of Mango's distinction between church in Book 1 of his panegyric The Buildings-a work of Procopius's reliability as a witness of the building itself, with uncertain date, and fraught with distortions, both intentional which he was quite familiar, and of its construction, with which and accidental.16 A source of proven mendacity and unproven he was not. Procopius was abroad from 533 to 540, and his date is never a good starting place for an inquiry, but we need account of the original construction of Hagia Sophia is plainly not scrutinize Procopius's motives in the brief passages of The confused. But he spent many of his subsequent years in the Buildingsthat concern us. While Procopius might safely exagger- capital, and was certainly in Constantinople while writing The ate Justinian's achievements on the empire's periphery, he Buildings; otherwise he could not have had access to the could hardly misrepresent the physical appearance of buildings government records that he so plainly consulted.21 We can in the capital, which were in plain view to many of his readers. therefore say with some confidence that aside from a few brief A more vexing problem involves the date of completion of comments from Agathias and Paul the Silentiary, Procopius The Buildings, or at least of Book 1. Many dates have been alone among the sources provides a reliable eyewitness descrip- proposed, but those most commonly encountered in the tion ofJustinian's Hagia Sophia in its original form. Here, then, current debate are 554, before the collapse of the first dome, is a literal translation of the relevant passage in The Buildings:

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This content downloaded from 130.58.65.10 on Wed, 20 Nov 2013 11:29:22 AM All use subject to JSTOR Terms and Conditions And upon them [sc., the arches]hangs a rounded structure[kykloteres oikodomia]in the shape of a ring, fromwhich the day alwayssmiles first. For I am convincedthat it risesabove the whole earth;and the structure is discontinuedevery little while, purposelyomitted at enough intervals that the placesto whichthe gaps in the structurecorrespond might give admittanceto adequatelight.... As [each pendentive]rises the rest of the wayand is broadenedby the interveningspace, it culminatesat the ring [kykloteres]which it thus supports,and forms the remainingangles there. And rising upon this ring, an immenselylarge sphericaldome renders it surpassinglybeautiful. It appearsnot to rest upon the solid structure,but to coverthe space [as if] suspendedfrom the golden chain of heaven.22

There is one other relevant scrap of testimony from a near-contemporary, the historianJohn Malalas: In the same year, when the dome of the Great Church was being restored for it had been crackedin some places by the earthquakes whichhad occurredthrough God's Providence-... the easternpart of the vaulting [prohypostole]fell down.... The remainingpart that had stayed in place was taken down, includingthe arches [eilemata].23The dome wasrebuilt 20 [Roman]feet higher.24

Procopius's brief description, along with Malalas's claim that FIGURE 3: A dome that shares the curvature of the pendentives. In such an the second dome rises 20 feet higher than the first, has led at arrangement,the diameter of the half-sphereis equal to the diagonalof the squarethat least four scholars in this century to venture theories about the it describes. Between the pendentives, the lower parts of the half-sphereare cut off shape of the original dome.25 If Malalas's figure is accurate- verticallyto form lunettes. and most scholars have concluded that from an engineering standpoint it is quite feasible-then the dome must have been much from that of the pendentivesthemselves, which makes it highly shallower than it is now, perhaps shallow enough to share the probablethat the same radiuswas adopted for both. In effect,construc- curvature of the pendentives [Figure3]. tion of the notional continuous hemisphericaldome-of which the pendentiveswere the only parts that had so far been built-would TWENTIETH-CENTURY THEORIES simplyhave been resumeda little higher up, afterbeing cut off by the Mainstone's proposed profile of the first dome is the most cornice.27 current and physically plausible [Figure4, A]. Judging from the of some cornice blocks to the placement apparently original Kenneth J. Conant proposed a three-point dome profile, north and south, he concludes that were set all around the they but such a dome, rising steeply from its springings and then of the with a uniform tops pendentives, overhang correspond- abruptly altering its curvature into a flattened crown, even if it to the two lower nave cornices.26 This means that these ing rested on unmoving foundations, would suffer extreme tensile blocks-and thus the first dome-did not correct the deformi- stress toward the bottom, causing radial cracking as the flat ties of the circle inscribed in the 100-foot which was square, central area pushed out on the steep peripheral area.28 It is distorted the movements of the and arches. Mainstone by piers highly doubtful that the main dome of Hagia Sophia, with the a shallow dome that would have risen 28 feet from proposes added complications of unprecedented size and a less stable to crown 20 feet lower than the crown, as springing (i.e., present base, could possibly have had this profile. Malalas a bit on the north-south axis because says), elongated Mainstone's proposed shallow "saucer dome" has been of the "lifted somewhat above the cornice square's deformity, universally accepted since he proposed it, and I too have no two a low drum-like section at the foot to afford [about feet] by quarrel with the proportions he assigns to the dome itself. But I reasonable around it." passage must raise one major objection: Mainstone does not account for The only clues to its possibleprecise form are what we are told aboutthe Procopius's clear indication that a roundedstructure (kykloteres height of the crownin relationto that of the reconstructeddome, and oikodomia),pierced by windows, separated the dome from the what we can deduce about the precise forms of the pendentivesand arches and pendentives below. He dismisses the implications of cornice.In followingup these clues, it soon becomes apparentthat the this statement, as he dismisses Conant's theory, on physical radius of curvatureof the main curved surfacecannot have differed grounds: given that the crown of the second dome is fully 20

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This content downloaded from 130.58.65.10 on Wed, 20 Nov 2013 11:29:22 AM All use subject to JSTOR Terms and Conditions feet higher than that of the first, as Malalas attests, a drum Malalas's reported 20-foot differential is as reliable as Procopi- under the first dome would render it impossibly shallow, more us's eyewitness testimony of a "rounded structure";yet there is like an overturned platter than a saucer.29 The crown would still a way to reconcile these accounts.31 Rather than represent remain at the same level, while the drum would raise the the absolute difference in height of the two dome crowns above springings [Figure4, B]. the floor, i.e., the elevation, Malalas's 20 feet may refer only to Mainstone apparently prefers to interpret the rounded the relative heights of the domes from their springings, ignor- structure as his low "drum-like section" described above, sur- ing any change in the relative positions of the springings mounted by the windows piercing the proposed dome. Apart themselves. In other words, by a "lower" first dome Malalas's from the fact that a drum this low simply could not provide source may simply have meant "shallower,"while any mention head clearance for a person standing on the cornice as Main- of a drum under the shallower dome was lost in the transmis- stone claims, his reconstruction again misconstrues the place- sion. This drum, though it would decrease the disparity in ment of the windows (Figure 4, A).30 And a drum less than a elevations, may have been deemed part of the substructure and meter high, set back from the cornice as it must have been, consequently discarded from the account.32 could not even be seen from the floor or the gallery; so how I am satisfied tojoin the chorus of agreement that the earlier would Procopius have seen it? Even if he had ventured up to dome would indeed have been about 20 feet shallower than the dome such a level, minor feature would hardly have merited rebuilt dome, thus having a height from springings to crown of mention in his sketchy description of the building. Procopius's about 28 feet and the same radius of curvature as the penden- must have been a drum. But how kykloteres can it be reconciled tives.33 But the dome did not spring directly or almost directly with the low of the first reportedly profile dome? from cornice level, as modern theories contend. It rested upon a drum of modest height-though much less modest than A NEW PROPOSAL Mainstone's two Byzantine feet-which was vertical or near- Thanks to Malalas, both Mainstone and Conant labor tojustify vertical on the inside. This drum accommodated most or all of an dome whose original crown was 20 feet lower than the each window embrasure, and was distinguishable on the inside dome-Conant at the of sound present expense engineering, from the dome above by the geometric juncture of the sphere and Mainstone at the expense of Procopius's credibility. Mala- segment with the cylinder. With the drum, the crown of the first las was clearly not an eyewitness to the reconstruction, whether dome was perhaps about 10 feet lower in elevation than the or not he confused the pendentives (which were dismantled) existing dome, rising 38 feet from cornice level [Figure5]. with the arches (which were not). He was probably a resident of Antioch at the time he wrote this part of his chronicle, and CORROBORATION FROM THE SOURCES would have relied on secondhand from reports the capital for Agathias is silent on the subject of a drum, although his his information. There is no reason to assume good that contention that the second dome was "more securely set up"

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FIGURE4, A: Profileof Mainstone's proposed originaldome. The dotted line representsthe profileof the present dome. B: Profileof a "platter"dome with the same crown elevation but raised a springings.Only smallamount of outward movement of the springingswould cause the dome to collapse.

TAYLOR: FIRST DOME ON HAGIA SOPHIA 71

This content downloaded from 130.58.65.10 on Wed, 20 Nov 2013 11:29:22 AM All use subject to JSTOR Terms and Conditions FIGURE5: Proposed dome arrangementwith a fenestrated drum. The combined height of drum and dome would leave the crown 10 Byzantinefeet lower in elevation than that of the present dome. than the first may owe its self-assuranceto more thanjust the while the others did not. Most significant, the entire description thickening of the north and south arch crowns.There is no of the central space-arches, pendentives, drum, windows, and other direct writtenor architecturalevidence of a fenestrated dome-is meant to draw a direct parallel with Hagia Sophia. drumunder the firstdome of Hagia Sophia.Because there are Curiously, many scholars have ignored this reference to a drum no existing filiationsof this arrangementon so large a scale, in both passages of Procopius; and those who have acknowl- and becauseit seems an unnecessaryrisk on so novel a building edged it in the case of the Holy Apostles have disregarded the project, we are tempted to question Procopius's technical direct parallel Procopius draws with Hagia Sophia.36 Only competence. Since he was a layman,we tell ourselves,this is Mainstone calls attention to the drum mentioned in the Hagia surely one of the numerous cases where a panegyristis not Sophia passage, but he minimizes its visual and structural equal to his subject matter. But as it happens there is a importance. This passage rather weakens any suspicions that strikinglysimilar descriptive passage in Book 1 of TheBuildings, Procopius was describing the early Hagia Sophia from errant where the structurein question is better attested. It describes memory: whatever it is that the Holy Apostles has under its the domes on the cruciformChurch of the Holy Apostles in dome, he is saying, Hagia Sophia has it too. Constantinople,completed around 550, and demolished in There are, in fact, other descriptions of the Church of the 1469.34 Holy Apostles, one from the tenth century and one from the twelfth. Both are ekphraseis,but they were not written to The partof the roof abovethe so-calledsanctuary, at leastin the middle, commemorate a remodeling or rebuilding. In fact, it seems that is builtin a waysimilar to the churchof Sophia,except thatit happensto the tenth-century poem, by Constantine of Rhodes, represents be smallerin size. Forthe arches,four in number,rise up and are bound the building's fabric (if not decoration) much as it was when to each other after the same fashion [as Hagia Sophia,i.e., by penden- Procopius saw it four centuries earlier.37The poet goes along tives];and the roundedform [kykloteres]standing upon them is dividedby with the popular belief that the wonders he is describing are all windows,and the spherical shape arching above seems somehow to the work of Anthemius, an original architect of Hagia Sophia, hover on air and not rest upon the solid structure,although it is quite and Isidorus the Younger, who replaced its first dome (lines secure.In thisway, then, was the centralpart of the roof constructed.As 550-552). There is less agreement about the testimonial value for the sides [i.e., crossarms], which are four in number,as I have said, of the second ekphrasis, written in the twelfth century by theyhave been builton the samescale as the centralone, but missingthis Nikolaos Mesarites. one thing: belowthe domethe structure[oikodomia] is not dividedby We turn then to relevant in Constantine's windows.35 passages descrip- tion: So the church had five domes, one in the middle and one over each of the four arms. Certainlythe central dome, and And he [i.e., the architect] likewise constructed piers, four in number probablythe others as well (the word oikodomia,"structure," is ... which are allotted the task of carrying the central dome and the ambiguous)rested on drums;the central drum had windows, arches securely set [beneath it]. Constructing these [i.e., arches] against

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This content downloaded from 130.58.65.10 on Wed, 20 Nov 2013 11:29:22 AM All use subject to JSTOR Terms and Conditions just as many flanks of the single central part [i.e., the central square would be hidden from view by the cornice. The dome would defined by the four main piers],all arrangeddoubly like a cross,38and seem to be "hovering" several meters above the cornice, then constructingthis samewondrous form to the east,west, south,and flooded by light emanating from the unseen interval. Such an north [more arches,this time atop the piers of the four crossarms], he arrangement would make rather more sense of Agathias's assembled,extended, unfoldeda greatbuilding in five parts,enshroud- contention that the second dome, in which the windows are ing the edifice,which bears the hallowedshape of the cross,in domes as visible from all angles, did not "strike the spectators with as great as the slings [i.e., pendentives]he had unfurledinto a circle.He much amazement as before." wove one arch to its mate, wovecylinder again to cylinder;he tied pier to pier,one to another;and he bound [each]sphere, cut in halflike a hill,to THE PHYSICAL NATURE OF THE DOME anotherspherical construction.39 Large diameter and shallow profile are the two bugbears of As if toweringgiants had come forthand extended their hands into dome builders, and the first dome on Hagia Sophia carried the air, weaving together fingers to fingers, right hand up against its both to an extreme. The dome was far larger than any ever neighbor, in the form of well-rounded,much-turned cylinders, they [i.e., attempted in the East; this, combined with its shallowness (the the builders]constructed circular wheels, extending to them four well- radius of curvature at the intrados would be 68 to 70 feet, as fitting curves which the builders call slings [pendentives];and they opposed to 53 feet for the present dome), imparted severe [the wheels] likewisereceived five domes; but the architectarranged thrusts upon the substructure.44In cross-section, the vector of a the middle dome in a reverentway, so it would projectand reign over dome's combined lateral and downward thrusts is tangential to all and be the great throne of the Lordand shelterto the most-revered the dome's slope at its periphery; so the shallower the dome, image rendered in the middle of the renownedbuilding. You might the greater its lateral thrusts upon its supports [Figure 6, A and say that they [the domes] fashion a heaven from bronze-turned,fiery B]. The lateral thrusts of the proposed dome would quickly cylinders,and then, as they descend,that they convergehandsomely and marvelously,like heads, with the shoulders of the bronze-columned vaults....40

Here we have remarkable confirmation that a drum sup- ported not only the central dome of the Holy Apostles, but apparently each of the other four as well. The central dome, being "higher" than the others, presumably had a taller drum-tall enough, undoubtedly, to contain windows. The A original Church of the Holy Apostles, dedicated in the fourth century, probably had a fenestrated drum over the center, surmounted by some sort of dome.41 We may reasonably assume that this feature was copied in the church's later manifestation under Justinian. Unfortunately, the tenth- century poet says nothing about the placement of windows, B although his apostrophe to Christ Pantokrator, depicted in the dome's intrados, refers to the Crucifixion and the Second Coming as sunset and sunrise-times of day that were (and still are) rendered especially magical through Hagia Sophia's crown of windows.42 So in Constantine of Rhodes's ekphrasiswe have written confirmation of Procopius's description of the central vaulting of the Church of the Holy Apostles.43 It is hard to avoid the conclusion that in this church we have the only attested filiation C of the great experiment atop Hagia Sophia. At the very least, we must conclude that the central domes of the two churches were highly similar on account of the identical visual effect they FIGURE6: Profilesof the present dome (A), a "platter"dome (B), and the proposed had on Procopius; for the drums surely contributed to the dome (C) showing approximatethrust lines of each near the springings.The platter illusion that the domes were levitating. This effect would have dome presents the least effective engineering solution; its thrust lines do not deflect been especially dramatic from the floor of the nave directly into the arches, but into the less stable drum, which is consequently prone to greater below the dome, where most or all of the drum and its windows outward movement.

TAYLOR: FIRST DOME ON HAGIA SOPHIA 73

This content downloaded from 130.58.65.10 on Wed, 20 Nov 2013 11:29:22 AM All use subject to JSTOR Terms and Conditions have peeled apart an unbuttressed drum.45 Although well- THE CASE FOR ORIGINALITY integrated ribs would have minimized radial cracking in the When remarking upon the genius of Hagia Sophia, one must dome, the drum itself was extremely vulnerable to cracking- try to break ranks with John Ward Perkins's archetypal archae- especially above the window embrasures, the points of least ologist, who "has a natural bias toward orderly classifications resistance to the expansive tendencies of the dome. There- and tidy schemes of evolutionary development;... [whose] fore, the drum would have had substantial buttressing on the whole method tends almost inevitably to emphasize rational, outside in the form of spurs between the windows similar to evolutionary patterns at the expense of the irrational element those on the dome today, but probably higher and heavier.46 introduced by human behavior and by the hazards of human Perhaps the space above the windows between the spurs was history."50Many of the ideas in the great church were new at heavily clamped. The heavier the buttresses, the more they the time, and cannot be explained as the inevitable consumma- would absorb the lateral thrusts, thereby deflecting the tion of a longstanding intellectual and artistic process. The thrust lines downward into the arches and pendentives [Figure number of windows encircling the dome, for example, far 6, C]. If the thrust lines had remained too flat to angle into exceeds any known Byzantine precedent or successor. Though the arches, the drum probably would have collapsed almost the idea of a masonry dome on a cylinder had existed in the immediately. This constraint limits the drum's viable height western Roman Empire for centuries and was familiar in the to about 10 feet on the inside. This would furnish more than East beforeJustinian's reign, Hagia Sophia's vaulting scheme as enough headroom around the cornice, while retaining enough a whole-as opposed to the sum of its parts-is without visible presence to attract Procopius's attention and convey precedent.51 Scholars have looked to other sixth-century the remarkable illusion of a lid hovering just over the pot churches such as S. Vitale in Ravenna and SS. Sergius and (Figure 5). Bacchus in Constantinople for architectural comparanda, but In recent years a great deal of energy has been devoted to these buildings' central vaults can claim only the vaguest modeling the structural characteristics of Hagia Sophia's main kinship to the early dome on Hagia Sophia. Slobodan Curcic vaulting system. To my knowledge, all of the models of the makes an intriguing case for the fifth-century canonization of a original dome to date have started from the assumption that it central dome type continuous with the four pendentives (Fig- sprang directly from cornice level, following Mainstone's recon- ure 3).52 This hypothesis is attractive, though tentative; it is struction.47 Obviously, the present proposal offers a signifi- certainly possible that the architects originally envisioned just cantly different profile whose structural viability could be such a scheme on Hagia Sophia, with forty windows in the tested, at least in a preliminary fashion, using finite element dome, only to modify their plans later. modeling techniques. Common sense dictates that of all the risks taken with the The findings of Swan and (akmak "tend to dispel the new church, the most precarious-the dome-would be the notion that the flatter original dome caused the excessive most likely to receive conservative treatment grounded in the spreading observed in the structure, since the steeper present lessons gained from previous successes. One sensible choice is dome would have produced greater spreading, at least at the the one offered by Curcic.53 A less effective choice, both springing level of the main piers."48Likewise, Robert Mark and aesthetically and structurally was the full hemisphere, which his colleagues find that "the changing of the first to the second had proven itself on immense buildings in Italy and possibly in dome configuration had only small effect on relieving the total Syria and the Levant as well. outward thrusts on the main piers."49In fact, a more substantial To understand the architects' unorthodox decision, we must structure such as the one I have described might account for the look briefly at structural mechanics from the viewpoint of the early pier spreading; the combined weight of the dome and sixth century. As mathematicians and architects, Anthemius drum would have borne down upon the half-dry, inadequately and Isidorus the Elder would have had occasion to study the buttressed east and west arches, causing their springings-and structural phenomena of large buildings in Constantinople, thus the main piers-to spread to the north and south. Asia Minor, and perhaps Italy and Greece as well-if not Depending on various characteristics of the drum-stiffness, personally, then by means of knowledgeable master builders in elasticity, plasticity, tensile strength-and the degree to which their circle. But their understanding of structural mechanics it was bonded to the arches and pendentives, the lateral thrusts would have been relatively limited. InJustinian's time, and for a of the dome, mostly absorbed by the drum buttresses above the millennium thereafter, a sort of aesthetic branch of geometry, level of the arch crowns, may have had considerably less effect buttressed by empirical rules of thumb and accumulated wis- upon the arches than at present. The drum would have offered dom, governed most structural decisions.54 less resistance to the inward thrust of the semidomes, and must Anthemius and Isidorus might have used the following four have contributed to the seismic instability of the vaulting rules of thumb: (1) Arches and domes of shallow profile tend to system. exert greater horizontal forces on their supports than those of

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This content downloaded from 130.58.65.10 on Wed, 20 Nov 2013 11:29:22 AM All use subject to JSTOR Terms and Conditions semicircular profile; (2) assuming well-anchored springings, to take place. The so-calledlori [the tympanalying directlybelow the arches and domes of full semicircular profile tend to be northand southarches] had been raisedup, carying the masonryof the inherently less stable than shallow ones, flattening at the crowns church, but everything underneath was labouring under the load, and spreading toward the bottom; (3) buttressing an arch or a making the columnswhich stood there throwoff tiny flakes,as if they dome at its lower levels will mitigate both of these problems; had been planed.... [Justinian]ordered them immediatelyto remove and (4) placing weight on top of an arch or a dome will the upper partsof the masonrywhich came into contactwith the arches, exacerbate both problems. and to put them back much later, as soon as the dampness of the These and other rules gave Byzantine buildings a chance for masonryshould abate enough to bearthem.57 permanence; but the mathematical principles that made build- This account accurately describes the effect the spreading ings stand in the first place were poorly understood. Byzantine north and south arches would have had on the underlying architects probably lacked a precise understanding of the tympana and their supporting columns as the sagging crowns consequences of scale, a particularly relevant concern in the bore down upon the masonry below. This event must have building of Hagia Sophia. Modern statics reveal that as the alerted the architects to the risks of extreme downwardthrusts, linear dimensions of objects increase at a steady rate, their such as those that the massive weight of an entire hemisphere inherent thrusts and counterthrusts increase exponentially.55 would exert upon the arches.58 So their solution was likely to But in Justinian's time this principle could be understood only reflect a conscious compromise entailing neither excessive in the vaguest terms, perhaps as an empirical assessment of the weight nor excessive lateral pressure directly upon the arches. countermeasures necessary for doubling the span of an arch or But what would a dome. present a safe compromise? A vaulting system that worked on a different substructure was not Still, by the year 537, having observed the movements of the guaran- teed to work on Hagia Sophia's huge, nearly completed building and attending to the rules of thumb undulating canopy. brick-and-mortar domes had visible mentioned above, the architects must have known that the Contemporary problems, and on a much smaller scale.59The hollow ceramic tubes used semidomes were providing more effective buttressing against in late antique African and Italian domes, such as the one on spreading of the arches than were the north-south buttresses, the fifth-century baptistery of Neon in Ravenna, were ex- and hence the critical problem was with the north-south axis. but would have the tensile to Despite the structural benefits of a dome continuous with the tremely lightweight; they strength resist cracking near the base of the huge dome, or the pendentives, and the architects' empirical knowledge of this plasticity to survive an earthquake? The architects faced a fact (persuasively argued by Curcic), they probably knew that a bewildering array of problems in their choice of a dome and its shallow dome anchored directly to the arch crowns, with its shape materials.60 radial horizontal thrusts, would have aggravated the tilting of The proposed dome-drum combination have seemed the north and south arches and their piers, whereas the dead may an attractive middle road between dangerous extremes. The weight of a full half-sphere with its necessary panoply of radial relative lightness of a shallow dome using low-density materials or stepped ring buttresses (the staple of classical and contempo- with high tensile strength was ballasted with a rary architects) would threaten to overwhelm the spreading buttressing eastern arch. structure that would deflect the dome's thrust lines downward through the building's bulk. This road had its which The architects were taking other measures to address the pitfalls, may soon have become evident in radial above the crises developing in the substructure. Mainstone has demon- cracking windows. But the architects could not have divined all the strated convincingly that before the dome was even begun, the structural weaknesses of their formidably original (and bril- north and south buttresses were modified to help them bear liantly improvised) masterpiece. Had they done so, it the unexpectedly great outward forces of the spreading east probably would not have wound up such a after all. Theirs and west arches: the passageways between pier and buttress at masterpiece was in fact a solution to a the floor and gallery levels were narrowed, and the buttresses visually satisfying practical problem, and their fears of alternative an were heightened.56 This is evidence that Anthemius and Isid- given well-grounded options, intellectually unexceptionable one as well. But the orus knew the risks of compounding the lateral thrusts on the surely venture was not without a certain a wish to crown a piers, as would a shallow dome against the stiffening arches. derring-do, great achievement in exalted fashion. Second, Procopius gives a remarkable account of another truly emergency measure taken during construction, and it has the ring of truth: Notes I C. Mango, TheArt ofthe ByzantineEmpire, 312-1453 (Englewood Cliffs, N.J., 1972),80. But in the process of buildingthe other arches,indeed, those namely 2We do not know when Agathias moved to Constantinople,but he was whichare turnedtoward the southand the the chanced north, following practicinglaw there as a fairlyyoung man.The firstdome collapsedwhen he was

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This content downloaded from 130.58.65.10 on Wed, 20 Nov 2013 11:29:22 AM All use subject to JSTOR Terms and Conditions 16 twenty-fiveor twenty-sixyears old. Even if he did not see the first dome AverilCameron, Procopius and the Sixth Century (Berkeley and Los Angeles, personally,his good friendPaul the Silentiarywould have been a reliablewitness 1985), 110. to its splendorsand weaknesses. 17Procopius could, of course,have possessedin 559 descriptivenotes taken 3 R. L. Van Nice, 'The Structureof St. Sophia,"Architectural Forum (May beforethe collapse.But TheBuildings has the characterof a hastilyconceived and 1963): 131-38 and 210, at 137. haphazardlycompiled work; and it is unlikelythat the author,whose descrip- 4 The definitivesurvey drawings of HagiaSophia are to be found in R. L. Van tions of churchesare usuallyvague and perfunctory,would have taken notes Nice, St. Sophiain Istanbul:An ArchitecturalSurvey, 2 vols. (Washington,D.C., describingany church-even Hagia Sophia-on his own initiative.Although 1965 and 1986).Several of the drawingsare reproducedin HagiaSophia from the Michael Whitby ("Justinian'sBridge over the Sangarius and the Date of AgeofJustinian to the Present, R. Markand A. S. (akmak, eds. (Cambridge,1992), Procopius'De Aedificiis, "Journal of HellenicStudies 105 [1985]: 129-48) remarks appendix. thatthe descriptionof HagiaSophia is suspiciouslybrief, it is actuallymuch more 5 All measurementshereafter are in Byzantinefeet. As Mainstonecalculates detailedthan descriptionsin the laterbooks, which read like preparatorynotes. it, the Byzantinefoot used for HagiaSophia is approximately0.312 m, or 1.024 Cameron charts Procopius'sgrowing disillusionmentduring his later years, Englishfeet. See R. Mainstone,Hagia Sophia: Architecture, Structure and Liturgy of whichwould explain his loss of zeal towardthe end of the project.It is unlikely Justinian'sGreat Church (New York, 1988),6, 177. On the variabilityof Byzantine that the Procopiuswho wrotethe scurrilousSecret History could havewritten the measures, see E. Schilbach,Byzantinische metrologische Quellen (Thessalonike, celebratoryfirst book as late as Whitbybelieves. 1982). 18 C. Mango,"Byzantine Writers on the Fabricof HagiaSophia," in Markand 6 This is the height of the top surfaceof the upper nave corniceas measured Cakmak,Hagia Sophiafrom theAge ofJustinian, 41-56, at 42-44. 19 by L. Butler, "Hagia Sophia's Nave Cornicesas Elements of Its Design and Cameron,Procopius, 10. Structure,"in Markand (akmak, HagiaSophiafrom theAge of Justinian, 57-77, at 20 Ibid. See also G. Downey,"The Compositionof Procopius'De aedificiis," 58. Transactionsof the AmericanPhilological Association 78 (1947): 171-83, and 7Van Nice and Mainstonehad a pointed disagreementon this issue. Van Whitby, "Justinian'sBridge," which endorse the later date. The basis of Nice claimsthat the semidomeshave no buttressingeffect ('The Structureof St. contentionis Procopius'sstatement in 5.3.10 that the bridgeover the Sangarius Sophia,"138, 210), whereasMainstone argues that they do (HagiaSophia, 94, Riverwas unfinished at the time of writing,whereas Theophanes's Chronographia 165, and figs. 114, 191, 192). The physical evidence seems to support (annomundi 6052), writtenaround the year 800, relatesthat it was begun in the Mainstone. year560. Whitbydoes not insistthat Book 1was written after the collapse,but he The eastern and western main arches have each fallen once in the prefersto thinkso. 21 meantime,causing partial collapses of the dome. The westernportion, which fell See Mango,"Byzantine Writers," 42-44. 22 v in the tenthcentury, was sloppily reconstructed. The westernarch was thickened iwpeev & avc)v K0olK:ep^4 oiKofioCa ?v arpoyyr6X eijpta 60et dait L7aaixoav, &aXuiEt by severalfeet, the ribswere made halfagain as thickas before,and twowindow &tayE4itpdnov f1 AipaL.impadpet 'p y 4ap oat,vi, yiv Kio 6oov embrasureswere filled in undereachjoin betweenthe old sectionand the new.A T6 oiKo66&oIpiKart& pax6, mtenetS napeltpvovooaoinov, TOI Xtwpo., & collapsein the east, almostidentical to the sixth-centurycollapse, took place in ou06 t6 iTprTpvov Tr; oicoSoWia; aPaBoive elva, yyox; &apKOi; ryoMo i t6 Xot6v the fourteenthcentury and was repairedin a similarlyuntidy, but less cautious, Etva. '. au. vavapaivowa & (i tp'ytovoup Ecciao KpqiT,) manner. eupuvopvnl T1 WlEta4i) X'p ?;Q T KIcuKXOTcpe; TEXEVTC,O6 tui avevtxet,ycviia; 9With its concavewebs and archedwindows, the present dome consistsof Te ta XkeITOlpvat; vtcO0a nOtLvatt. toviou & toiKicKCXotEpoxV; gA CYOYI; multiple radiatinggore-like sections, billowing up like a circularscallop shell itXaveornrtd t ; oeatpoet81i; 06Xo; totfaTatavT6 &aipo6voi Ex;e6t0aiov. around the peripheryof the dome. So-called gored domes (or "umbrella," SoIKEl&0i OK rn oStppd; Tfq oiKo0o6LaLo tiatvm &XX&a odipiu T XpXi3 dr6 "pumpkin,"or "shell"vaults) were common in Roman times-for example, at toi) oipacvoi TmpjvTv KaiaX6etv rbv X6)pov. Hadrian'svilla and the bathsin Baiae-but, as faras we know,never with arched My translationfrom Procopius,The Buildings 1.1.41-46, Loeb edition (Cam- windowsunder the end of each gore as at HagiaSophia. bridge,Mass., 1971), 20, using one textualvariant. '0As Paulthe Silentiary'seyewitness account attests (see above),the east arch 23 In fact,the archeswere not pulleddown, except perhapsfor remainsof the that had actuallycollapsed along with the eastern portions of the main vaulting. falleneastern arch. The crosssections of the northand southarches confirm as Agathiasmust mean that it was restoredto its originalform withoutmodifica- these arches were thickened on the inside without further tampering, tion. Agathiasattests; see Mainstone,Hagia Sophia, 95-96. Malalasmay be referring dismantledto allow the north and Il Mango, Art ofthe ByzantineEmpire, 78. to the pendentives,which must have been 12According to Mainstone,"60 per cent of the [present]north-south tilting of southarches to be thickened. the main piers had taken place by 558...." (Mainstone,Hagia Sophia,96.) W. 24 Mango,"Byzantine Writers," 51. See also G. Millet,"La coupole primitive Emersonand R. L. Van Nice ("HagiaSophia: The Collapseof the FirstDome," de Sainte-Sophie,"Revue belge de philologie et d'histoire 2 (1923): 599-617, and E. Malalas Archaeology4 [1951]: 94-103) suggestthat the tiltingwas exacerbatedby failure Jeffreys, M. Jeffreys,and R. Scott, trans., The Chronicleof John (Mel- of the naturalrock on whichthe piers rested.The bedrockmay also have aided bourne, 1986), 297. These sources offer the relevant passage from Malalas in transmittingdamaging earthquakevibrations to the superstructure(103). alongsidetwo later accounts based on this passage. Mainstonesuggests that at the time of rebuilding,the squarewas roughly 100 by 2) E. Antoniades, 'EKipaot; ri'A yi z?oZiar, 3 vols. (Athens, 1907-9); FirstDome of St. and 102 Byzantinefeet (31.2 m by 31.8 m) and the dome'sdiameter varied by about Millet,"La coupole primitive"; K.J. Conant,"The Sophia, and 3 feet (.9 m) (HagiaSophia, 209, 215). The deformityof the rebuiltdome todayis Its Rebuilding,"Bulletin of theByzantine Institute ofAmerica 1 (1946): 71-78; much more pronounced;by Van Nice's calculations,its major axis is 2.55 m Mainstone,Hagia Sophia, 209-12. 26 Nave Cornices." longer than its minoraxis, over 8 Byzantinefeet ("TheStructure of St. Sophia," On these lattercornices, see Butler,"Hagia Sophia's 27 138). Mainstone,Hagia Sophia209-10. Mainstone'salternative proposal that 13 a This necessitateddismantling all or part of the pendentives.Failing to do the roundedstructure is the "cornicearound the tops of the pendentivesand is so wouldprobably have resulted in grossdistortions such as the one visiblein the ring of windowsaround this, both as in the rebuiltdome" (Hagia Sophia, 127) that the structure not northeastpendentive today, the resultof a decisionnot to dismantlethe entire baffling.As we have seen, Procopiusclearly indicates itself, pendentiveafter the fourteenth-centurycollapse of the easternarch. the dome aboveit, containsthe windows. 14 28 of Mainstone,Hagia Sophia, 67-110, 185-217, and passim. Conant, "The FirstDome." Lucid nontechnicalexplanations masonry Concrete l5 Mainstone("Justinian's Church of St. Sophia,Istanbul: Recent Studies of its dome staticscan be found in H.J. Cowan,"A History of Masonryand Constructionand FirstPartial Reconstruction," Architectural History 12 [1969]: Domes in BuildingConstruction," in Buildingand Environment12 (1977): 1 ff., 39-49, at 44-45) claims that each of the main arches, given adequate and G. Ozsen, "Vaultedand Domed Structuresof the ByzantineMonuments in I. buttressing,could withstand any earthquake. He placesthe blameof the collapse Istanbul,"in StructuralRepair and Maintenanceof HistoricalBuildings II, on the inadequateconnections between the main piers and their north and Dominguezand F. Escrig,eds. (Southamptonand Boston, 1991),22-35. south buttresses.Failure of these connectionscaused the two eastern piers to 29 Mainstone,Hagia Sophia, 127. lean outwards,spreading the easternarch to the point of collapse. 30A less tangible, though to my mind persuasive, argument is purely

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This content downloaded from 130.58.65.10 on Wed, 20 Nov 2013 11:29:22 AM All use subject to JSTOR Terms and Conditions aesthetic. Windows raking inward as much as 50 to 55 degrees from vertical the piers connecting them) be construed as short arms of a cross. would present to the eye a ring of large blocks of dazzling light, darkening 39 n-AciaEt& ivao' unpapftow, i4t(M;.s... everything near them by contrast. Viewers contemplating the dome and its toix rT~vpkaiiv c4xipav xiit Tck &W[i8a; mosaic cross would have to strain to see past the diffuised corona of light 4ipCtv raX6vu4a;dla)411p6wpapva formed by such a contrejour.Although this arrangement would no doubt be tr6ocatrit xpai;t iv6q peaopodX,oi impressive, the indirect light from unseen (or barely seen) windows in upright drvnpoanro4 Tra ylcattapTiaa;, embrasures recessed behind the cornice would have had a more subtle and &in&d;6ciatz a raptick teTaypivar, ethereal effect. Einct,iai5rn6 Toxtot 6 c%1'jiLarxNvov 31 The figure of 30 feet that appears later in Malalas (see Mango, "Byzantine np6i drvawroXv,&8osv Ti Koitpzaig4Lpiav, Writers," 51) is "presumably a copyist's slip, substituting X for Kc"(Mainstone, ipKICOVt jxokcX,nevraariWEt'ov &S1wov Hagia Sophia, 264), but it mayjust as likely reflect the author's own carelessness. -.yitpev, it#tetLv, pXkox=pkyav, Later chronologies that draw from the passage I cite preserve the figure of 20 a4xipu tc;oaainm; iycaX-6iWa;?v atyilv feet; but only the one surviving Greek manuscript of Malalas (a condensation of boaaoItn&p it4AXwaE KKXV) ci0Ev86vcti, the lost original history) actually includes the detail that the dome itselfwas raised urwupof)O4*tposra C6V aEBui6ttOV TiiOV, 20 feet. Two later accounts that borrowed almost verbatim from this passage- nXnccov&' &g?Wotv&sW4xa inp6; 6,i&xa, Theophanes' Chronographia and an anonymous fragment in J. A. Cramer's iriXtvSpovmn1Ot; t43~c)iv8pW npoainXowwv, AnecdotaGraeca-replace the word troullos("dome") with ktisma("building") and ntvat3 i inrvabrv&Xov 6).X inpoa6tov, hyphos("web, structure") respectively. rKdta0oipav 11iitriTgovOtcarEp X60ov 32 On a slightly more fanciful plane, the Narratio de S. Sophia, also called the &iU-0 aoivdcnnwv aatripoi6px apcuvOiact. TDiegesis,a semilegendary eighth- or ninth-century account of the building and My translation and emphasis from lines 562, 565 81 in Legrand's edition. rebuilding ot the church, which claims the second dome was actually lowered 40 EL(y, k; Yi-yaVTES i)WOSiP5E0lnC6TE; (albeit by five fathoms), may carry a grain of truth. For an eyewitness couldjust as KCtLXICtttX EKTEiVOV'T it; 16V &k.pa easily have ignored the greater depth and pitch of the new dome, and fixed his iccet8aiwtsXot; nv 6Xav-re Xovq8aKwniXow attention on where it was anchored-not up on a drum as before, but down on ariino'twaG' ai,toix; &kt&; inp 6vntXckuc the crowns of the arches themselves. In fact, two of the three reasons given for 6iwiv xuXiv8pov cirt?po3v ino)iup6~wv, the dome's collapse in the Narratio sound quite plausible: the emperor "was too ioWi8aOEipytmCavTo wuwKXruVO&noi,, hasty in removing the wooden supports [i.e., centering] that were in the dome so aiXt Ttnapa; tEtVOVTE( iiiicX0 E-WTOoU, as to cover it quicklywith mosaic," and "he made it [too] high [i.e., on a drum?] so &; a0v86vaiwrKaiXoiv ipyocruvOirat, as to be seen from everywhere" (Mango, Art ofthe ByzantineEmpire, 102). A drum acairipa&xov ri EcpiGWLouiigiaT1; under the first dome would have seemed an obvious agent in the collapse and 0nx1v rTv p?aiiv Inpoi5Xctv uE &oic.etv 0' 6Xzov hence would be avoided in the rebuilding. So by dispensing with the drum, the 6 TCXViril;iTriI4EV ?1XJEki6U P61iT dome would be "lowered." Mango suggests that the Narratio's strange blend of 4EXXoua(v E'tVm &an&roru pkyav 8p6vov fact and fancy is the result of oral traditions ("Byzantine Writers," 49). Tfi;6K6voq '& fT; 6nnpTip?ouacbniv 33 Mainstone, Hagia Sophia, 209 12; R. Mark and A. Westagard, 'The First riS;irpai4cia Ev picy(pK)xLtvo-3 866 o Dome of Hagia Sophia: Myth vs. Technology," in Domesfrom Antiquity to the ,i-not; &v ai6Tia o6prv6v wictraptiat Present,I. Mungan, ed. (Istanbul, 1988), 163-72. eKXawxot6pvwv ipxi$ o'icxuXtagdrov 34 See Richard Krautheimer, Early Chnistianand ByzantineArchitecture (Har- Kdwttwt0t ai?rkxt xawmaoucaN 6pli6at mondsworth, 1986), 242. tpoat; wicaaptv dk wdpa; XrCXKEPl6XaV.... 3 & 0 'Xi V " 6po14 ?Ovo itpaoeioso KtXolaoupkvo Kicao1pOcv tcj( -rfq Zias My translation and from lines 617 34 in edition. - emphasis Legrand's xpuj KcaTCi acra dpYaatat, 8 6n raitaa 41 YE 4otpi inXAvvE ti)tvwv Richard Krautheimer, "On Constantine's Church of the Apostles in di Lkao0oiafOai PEYtOEtOlvaiVEt. Ti ydp i4ii&; Ttaaape; ouaaKamtic r6v Constantinople," in idem, Studies in Early Christian, Medieval, and Renaissance Art at6-rv rtt icdt auv6tovt 1odppTvtai K d(xt iat; trpinrov wcitb xuicXovc; (New York, 1969; article first published 1964), 27-34. On the date of this Kia pi&x8a t6 ti u7rEpavEawT11Kxtdd r&; 8tupTrr, a0atpoa&4; inci)AVtoi*evov building, see G. Downey, 'The Builder of the Original Church of the Apostles at i~nrp6v OpEEwpiFJaftifov &oKEt KLtOxoK tini aTEppa; Tni oixo8oj?tti'or, vct, Constantinople: A Contribution to the Criticism of the Vita Constantini Attributed Ti6 Ktin&p d0a aEiai Ei' iXov. CLv oi'v Tf; 6poi; pikaov tine ,arroilrat' Kxar& to Eusebius," Dumbarton Oaks Papers 6(1951): 53 80. oau. fntp icarta ?ri,inz6tu pLYE, O TXS AEnpaiS riaaaLPa4Oi~ , giOt rtipqat, 4Ca( 0t6 42 Like Nikolaos Mesarites after him (see A. W. Epstein, 'The Rebuilding and 81 ln oi6 cdpyao-nat, toi?ou g6vo-o iv&ovtro;, 611"roU aTiatptxo-i EvtpOcv Redecoration of the Holy Apostles in Constantinople: A Reconsideration," 8titpiq,m A1oiwos6olia Gupiatv. Greek, Roman, and Byzantine Studies 23 [1982]: 79-92; Nikolaos Mesarites, translation and from The My emphasis Procopius, Buildings 1.4.14-16, p. 50 in Description of the Church of the Holy Apostles at Constantinople, Transactions of the the Loeb edition. American Philosophical Society, n.s., 47, pt. 3, trans. G. Downey [Philadelphia, 36 Even the Loeb edition translates the same in word, kykloteres,differently 1957], 855-924), the Rhodian's richly metaphorical wordplay on the effulgence each account. of Christ Pantokrator, who is depicted at the crown of the central dome, seems at 3 des oeuvres d'art et de des Saints de "Description I'Eglise Ap,6tres least to hint at nearby windows illuminating the image: "When will I see the glow Constantin le ed. E. T. Constantinople par Rhodien," Legrand, commentary by of your rising? Did you go off like the sun swiftly to the setting? When might I des etudes 9 Reinach, Revue grecques (1896): 32-103. Constantine's poem actually see the coming dawn of your rays? [As Nikolaos describes the mosaic later, lauds monuments in of which eight Constantinople, the church is the last. A stylized solar rays emanate from the central image on the dome.] Or what to describe in like manner 272 and promise Hagia Sophia (lines 282) goes star will be your morn-harbinger, announcing to me your return, my Logos?" unfulfilled, which that the is see C. suggests poem unfinished; Downey, (x6f 6Wyo4at ( ~ drvarnoXij Xapun8i66va; 6M?X0c.bE ijXto; c;Eiq8iav rtiXoi; x6f "Constantine the Rhodian: His Life and Works," in Late Classicaland Mediaeval 6p6pov i&o itp6popov a6iiv dKtivwv; T'1Ino1oS dtarp, Ti; & a6; y iwoa6po;. Studies in Honor ofAlbert Mathias Friend (Princeton, 1955), 212-21. Downey (at 7npop-nviov pot a31v 6tvda'acrv, A&yt, and R. Krautheimer Note 216) ("A onjusfinian's Church of the Holy Apostles in My translation from lines 974-78 in Legrand's edition. in Tisserant 2: at 4 Constantinople," Melanges Eugene (Vatican City, 1964), 265 70, It is enough to establish that the central dome remained relatively cite one recorded instance of Basil 270) only remodeling, by I between 868 and unchanged. We cannot verify that by the tenth century there were not windows in 881. This "was no doubt limited to but since it included the the four repairs; buttressing, outer drums; after all, St. Mark's in Venice, an apparent filiation begun old was in building apparently bad shape." in the eleventh century, has windows in all the domes. But at St. Mark's there is 38 Each of the main arches of the central was means of a barrel bay coupled, by really only one drum, under the center dome; so it is impossible to sayjust how to a arch from the vault, parallel adjoining bay, as at the present St. Mark's in closely this church resembles its parent, which we are now led to conclude had Venice. The barrel vaults are thick enough so that they may (if one can iguore drums under every dome.

TAYLOR: FIRST DOME ON HAGIA SOPHIA 77

This content downloaded from 130.58.65.10 on Wed, 20 Nov 2013 11:29:22 AM All use subject to JSTOR Terms and Conditions Krautheimer,"A Note on Justinian'sChurch," cites four depictionsof the Quasi-Staticand SeismicAnalysis." For a criticismof these approaches,see church in illuminatedmanuscripts, three from the Menologiumof Basil II (c. RowlandMainstone, "Questioning Hagia Sophia," in Markand Cakmak,Hagia 979-89) and one from the homiliesofJames Kokkinobaphos(twelfth century). SophiafromtheAge ofJustinian, 158-76. All of these illustrationsshow the church-albeit much stylized-with several 48 Swanand Cakmak, "NonlinearQuasi-Static and SeismicAnalysis," 265. domes, the centralone standinghighest on a fenestrateddrum. Krautheimer 49Mark, (akmak, Hill, and Davidson,"Structural Analysis of HagiaSophia," maintainsthat the multiple drums depicted in these illustrations,some with 879. 50 windows,attest a rebuildingof the churchsometime between Procopius's time J. B. WardPerkins, "Imperial Mausolea and Their PossibleInfluence on and the illustrationof Basil'sMenologium. This rebuildingincluded raising all EarlyChristian Central-Plan Buildings,"JSAH 25 (1966):297-99. the domes upon fenestrateddrums. Epstein,"Rebuilding and Redecoration," 51 The Pantheon in Rome (c. 124 C.E.), the Rotunda of St. George in givesample evidencewhy this conclusioncannot be supported.I wouldadd the Thessalonike,built by Galerius(d. 311 C.E.),and the churchofS. Costanzain followingreasons: (1) Krautheimer'spremise that no drums existed on the Rome (c. 350 C.E.) are well-knownextant examples of vaulted cylindrical original building is faulty; (2) he remarks that Constantine"stresses... the precedents.J. B. WardPerkins, "The ItalianElement in Late RomanArchitec- lighting of only the main dome over the center bay," an assertion I find ture,"Proceedings of the BritishAcademy 33 (1947): 163-94, offers instructive unsupportedin the text; (3) it is uncertainin the three earliest illustrations analogieswith such buildingsas the Basilicaof Maxentiusand S. Lorenzo in whether drums are being depicted, or simply the entire substructureof each Milan,but in complexityHagia Sophia far exceeds these buildings. cross-arm;and (4) small fenestrateddrums were so common in Byzantine 52S. Curiic, "Design and StructuralInnovation in ByzantineArchitecture architectureby the tenth century that they had become a convention in before Hagia Sophia," in Mark and (akmak, Hagia Sophiafrom the Age of illustrationsof buildings, whether the subjects actually had them or not. Justinian,16-38. 53 Medievaldepictions of buildingscan almostnever be takenat face value. Even S. Curcic,"Design and StructuralInnovation." But for the interveninglow Renaissancedepictions can be grosslymisleading: for example, the Nuremberg drum,Mainstone's proposal is identical. 54 Chroniclepanorama of Constantinople,dating from 1493, depicts not only the See Mainstone,Hagia Sophia,168-69. It is not my intent to enter the Nea Ekklesia(?) as a cluster of domed, faceted silos, but Hagia Sophia as debateabout the natureof architecturaltraining during this period, but it seems Florencecathedral, with a huge hexagonalfenestrated drum and a Brunelles- foolish to claim, as Robert Browningdoes (Justinianand Theodora[London, chianlantern sprouting from the crownof the dome. 1987],75), thatAnthemiusand Isidorushad littleuse forempirical models or for 44 Followinga rule that seems to apply to vaulting throughoutthe build- traditionaltraining in the building craft;see A. Petronotis,"Der Architekt in ing, Mainstone,Hagia Sophia, 210, suggeststhat the thicknessof the firstdome Byzanz,"in Bauplanungund Bautheorie derAntike (Berlin, 1984), 329-43; H. A. wasabout 5 percentof its radiusof curvature,making it nearlya foot thickerthan Meek, "The Architectand His Professionin Byzantium,"Journal of the Royal the present dome. This suggestionis highly speculative;more likely,strength Instituteof BritishArchitects 59 (1951-52): 216-20; G. Downey, "Byzantine was sacrificedto lightness in the dome, while the converse held true for the Architects,Their Training and Methods,"Byzantion 18 (1946-48): 99-118. drum. Evenif they did not have much personalbuilding experience, they would have 45C. C. Swanand A. S. Cakmak,"Nonlinear Quasi-Static and SeismicAnalysis consultedextensively with men who did,just as Brunelleschidid in Renaissance of the Hagia Sophia Using an EffectiveMedium Approach," Soil Dynamicsand Italy;see Mainstone,Hagia Sophia, 157. "Anthemiusand Isidoruscould use only EarthquakeEngineering 12 (1993): 259-71, at 264, calculatea force of between practicalexperience in buildinga guide to structuralreliability," writes Robert .200 and .375 meganewtonsper rib for a dome model similar to the one Mark."Geometry did play a majorrole in their conceptualdesign; howeveras proposed by Mainstone.They assume that the present dome is 26 percent no less an observerthan Galileo also commented, geometryalone can never heavierthan the original;but under my proposal,the originaldome (drumnot ensurestructural success." See R. Mark,Light, Wind, and Structure:The Mystery of included)may have been lighter even than this, therebyreducing the lateral theMaster Builders (Cambridge, Mass., 1990), 88-89. 5 thrustbelow the proposed magnitude.The verticalthrust, of course,would be "In general, [serious implicationsof increased scale] arise because the substantiallyincreased by the weightof the drum.A massiveiron tie aroundthe forcesassociated with self-weightincrease at a greaterrate than the resistances foot of the dome, similarto those appliedto the presentdome in the nineteenth opposed to them. Doubleall dimensions,and the forcesincrease eightfold, while century,could have reduced or even eliminatedthe lateralthrusts; however, the cross-sections,and hence the resistances,increase only fourfold." Mainstone, there is no indicationthat this expedient was used in the sixth century.The HagiaSophia, 166. 56 technologyto producelarge iron chainscertainly existed, as Procopiushimself Ibid., 200-203, 209; Swan and (akmak, "NonlinearQuasi-Static and attests(Wars 5.19.24-26). SeismicAnalysis," 265-66. 57 46 There wereprobably forty windows and spursaround the originaldome, as Procopius,The Buildings, 1.1.74-77; Loebtranslation, p. 31. now;for the rebuilders,concerned as theywere with greater permanence, would 58 These downwardthrusts would add to the spreadingof the arches,which in not have increasedthe numberof windows,clearly among the weakestfeatures turnwould compound the lateralthrusts upon the main piers. 59 in the originalstructure. "There are excellent examples of radial cracking of domes due to 47S. Kato, A. Takayoshi,K. Hidaka, and H. Nakamura,"Finite-Element circumferentialtensions and thrustingapart of supports.... Similarevidence Modeling of the First and Second Domes of Hagia Sophia," in Mark and musthave been visiblein some of the earlierbuildings of Constantinople:indeed (akmak, Hagia Sophiafrom theAge ofJustinian, 103-19; R. Mark, A. S. (akmak, SS. Sergiusand Bacchustoday exhibits much the same distortionsin its galleries and M. Erdik,"Preliminary Report on an IntegratedStudy of the Structureof as can be seen in St. Sophia,and it is almostcertain that the pronouncedoutward HagiaSophia: Past, Present, and Future,"ibid., 120-31; R. Mark,A. S. Cakmak, tiltsof its piersand columns,for instance,were clearly apparent when St. Sophia K. Hill, and R. Davidson,"Structural Analysis of Hagia Sophia: A Historical wasbuilt." Mainstone, "Justinian's Church," 43-44. 60 of the Perspective," in Soil Dynamicsand EarthquakeEngineering VI, A. S. (akmak and C. On the dome's masonry,see R. A. Livingston,"Materials Analysis A. Brebbia,eds. (Southamptonand Boston, 1993), 867-80; R. Markand A. Masonryof Hagia Sophia Basilica,Istanbul," in Cakmakand Brebbia,Soil Westagard,"The FirstDome of HagiaSophia"; Swan and (akmak, "Nonlinear Dynamicsand Earthquake Engineering (see n. 17), 849-66.

78 JSAH / 55:1, MARCH 1996

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