Ball has written a minutely detailed survey of the masonry of the Esquiline wing of the Domus Aurea which carries to a new level work and ideas raised in his UVA dissertation and in a lengthy article in a 1994 JRA supplement. His careful survey puts him in a position to make authoritative statements about the chronology and extent of the monument’s various phases, and from this he infers the Neronian architects’ methods and goals. In brief, Ball finds that the architects liberally appropriated and exploited pre-existing structures while imposing an overall plan upon them. Construction proceeded in an orderly way, rather than being interrupted or altered on the fly by a meddling Nero. Design problems and accidental discoveries while solving them led the architects by a clear evolutionary chain from a fairly pedestrian villa design in a first phase to the astounding Octagonal Suite. Secundum ea quae proponerentur, Ball’s chronological arguments appear secure, and his interpretation of the evidence offers an exciting new view of this most important Neronian monument.
I do not mean to call Ball’s honesty or intelligence into question by using the old jurist’s qualification. It is just a simple recognition of the obvious fact that consultation of this book outside of the monument itself requires an act of faith because there is no substitute for the autopsy this book demands. Ball’s photographs and plans help, but neither they nor a familiarity with the monument are suitable replacements for following the arguments while looking at the original. Even the experts (among whom I cannot be counted) are going to have to go back for a look.
Ball’s method makes this clear. He combines an empirically deduced principle of uniform building practices within phases with one of careful observation of whether walls abut or bond with one another (he is hardly the first to use these, of course). An abutting wall can be modeled by placing your balled fist against your outstretched palm: your fist is the end of one wall abutting your palm. Bonding walls are simply modeled by bringing your hands together at a 90-degree angle with your fingers interlocking but not curled around to grasp the backs of the other hand. Variations such as semibonding walls are possible, when a niche in the “palm” of the older wall has been carved to receive the abutting “fist” of a new wall. True bonding walls have a continuous concrete core and were certainly poured together as part of a carefully planned scheme, whereas abutting walls represent the adaptation of a new wall to an existing one (how long the earlier wall had been there is another problem, but it had at least cured). Ball is aware of the risk of tautology in this method and capably summons practical considerations such as accessibility, lighting, and fragments of ornamentation to clarify difficult passages. I, at least, found no arguments in the presentation of evidence that were not carefully and logically worked out.
The book is tripartite. A first chapter introduces the reader to the literary sources and the chronology those sources suggest, connecting them with the terminology (‘domus transitoria’, ‘domus aurea’) used both in antiquity and by archeologists today. A second part, comprising chapters two through five, contains the laborious analysis of the masonry, which is the soil in which Ball’s interpretation is planted. A sixth chapter offers three rich synthetic essays which reinforce the chronological survey, present comparanda, and discuss the nature of Roman architectural progress, respectively. A bibliography and index follow. Ball is a methodical man, as is apparent in his organization. Copious cross-references between main and ancillary discussions of masonry phases or groups of rooms insure that the reader can easily navigate the complex arguments. Presentation of data in the central section of the book progresses chronologically and thus, as it turns out, runs roughly from west to east along the Esquiline wing. Cross-referencing is therefore buttressed by the intuitively simple physical layout of the book. The endnotes are sensibly arranged under headers containing the pages to which they refer. The index is sparse, because Ball felt the arrangement of the text made indexing largely unnecessary. Concepts central to Ball’s interpretation of the architecture and some ancient names are listed. Given the disagreement some of his conclusions have provoked, an index of his references to modern scholars’ works would have helped a lot.
I have no desire to rewrite Ball’s case, but a book like this does require the reviewer to walk through the arguments, and for this I hope to be forgiven.
At a point before the great fire, Nero’s architects sought land for a suburban villa and, in the case of what we now call the Esquiline wing, annexed what property could be had between the main imperial residence on the Palatine and extra-urban imperial property to facilitate transiting the city (not that it’s such a hard walk). The architects Severus and Celer were practical men with the ability to see the potential for reuse in existing structures. So they annexed a bit here, bought out a building there, and out of it all created this ‘domus transitoria’ as an inwardly-turned, fairly conventional villa in the middle of the urban fabric. This first phase was more or less the western half of the Esquiline wing.
Came the great fire, and now Nero could build freely. The architects repaired some damage to the existing structures, altered them a bit, and added the eastern portion of the Esquiline wing with its distinctive Octagon Suite. The eastern and western blocks were joined through a clever reuse of pre-Neronian structures. The orientation of some of these (probably commercial) structures suggested the idea for the pentagonal court when a principle of symmetry was applied. The masonry exhibits one distinctive type (“E”) in all of the first phase, and another in all of the second, post fire building (“F”). In almost all cases where masonry appears mixed, Ball’s careful examination of abutments and other evidence clears up the confusion, supporting the view I’ve sketched above.
Ball not only argues that the architects’ clever incorporation of previous structures into the fabric of the Domus Aurea was a consciously applied method, but he also carefully lays out the building sequences to reveal the two main phases of building with just enough intervening work to distinguish them. In other words, neither Nero nor the architects imposed a disorderly building scheme on the structure, which was instead carefully thought out and constructed in complete campaigns of building (101-102). An important example will show Ball in action.
Tucked in among the pre-existing structures in the west half of the Esquiline wing is the inwardly-turned villa, revealed by peeling away all masonry subsequent to Neronian phase 1 (97 fig. 29). A large central courtyard has at its east end a compluviate atrium and behind that a sort of tablinum (rooms 20, 44 and 45, 45A on Ball’s plan). Along the south side of the courtyard stretches a series of barrel-vaulted sellaria (the odd numbered rooms from 23-37), generic barrel vaulted rooms common in commercial architecture having a broad door and a large perforation above that to offer clerestory lighting. At a point after this suburban villa was completed, it was adjusted by having a trabeated portico with a shed roof line all sides of the courtyard but the north. To do this, the clerestory windows of the sellaria had to be filled in — with phase 2 masonry — in order to give the new rafters purchase in wall sockets. Small residual clerestory lights were left in the fill above the line of the shed roof over each door, and these reach right up to the intrados of the room’s barrel vault (101 fig. 32). Ball’s conclusion, that the phase 1 masonry was complete and cured when phase 2 began, seems to me inescapable.
A barrel vault replaced the atrium of this villa (room 44) in the period of phase 2 construction (157-160, figs. 49-50); there was originally no purchase from which the vault might spring, so the architects built supports in phase 2 masonry which are simply extensions (as a new layer) of the old phase 1 walls, making the walls of room 44 now of double thickness. This is important not only for showing the discrete building campaigns but because of how the architects replaced the light lost with the atrium. The rooms on the north side of room 44 already had clerestory lights. Anyone could see that once the vault covered the atrium, these lights were going to become crucial. The architects saw this and hacked through the southern wall of the atrium to create mirroring clerestories for the south rooms (none had been placed there before because the northern exposure rendered them a nugatory supplement to the atrium). It is here, Ball declares, that a new, powerful architectural design was stumbled upon: the vault haunch clerestory, a hitherto unexampled way of profitably lighting rooms around a vault or dome (161-162). He argues convincingly that this was the moment of its invention because it was created as an unintentional side effect in a project with other goals. The vault and Otho’s (it seems) conversion of the old tablinum into a grotto (165) effectively hid the plan’s origin as a villa and thus masked the chronology.
Ball repeatedly stresses the architects’ ingenuity both in seeing the new and reusing the old. In the first of the synthetic essays (219-229), Ball argues that the Octagon Suite represents a daring and sophisticated reworking of what the architects had created in the vaulted atrium in the west side of the Esquiline wing. The vault has been plastically formed into a segmented dome, lit by vault-haunch clerestories on all sides but the south facade (which now, thanks to the fire, looked out on an open vista). An oculus mends the lighting problem created by the barrel vault in the old atrium. Ball argues that in fact, although the octagonal shape is striking, if you were to render it square you would be left with a design conceptually identical to the old atrium, with the tablinum replaced by the northern fountain room. Forming the square into an octagon permitted the architects to add the oblique rooms 123 and 125, which exhibit what Ball claims are the first extant examples of groin vault construction (228). If you cannot bring yourself to believe that the architects performed a mental molding of the atrium into the Octagon Suite, Ball’s argument will still function if they merely applied the various lessons learned in the atrium remodeling to the analogous task of creating a distinctive space in the east block.
The reader will now have an idea of how Ball works, and how thoroughly he has worked through the implications of the masonry. Ball’s discussion of the shape and structural engineering of the Octagon Suite is excellent, making it clear to my eyes for the first time how the walls of the octagon are little more than screening walls which do little to support the dome but make all the difference in creating a significant space.
The first of the synthetic essays (219-229) does the important job of succinctly laying out the main theses of the book. In the second, he seeks evidence for antecedents of the vaulted and domed construction in the Octagon Suite, finding it in the Baths of Nero, which he again argues was a transitional structure whose evolutionary features were obscured by fallacious teleological comparison with later, greater baths (229-258). The final synthetic essay (258-276) makes the nice point that concentration on individual architects is not as helpful as looking at the evolutionary series of structures produced by Roman architects in general. This is not new in itself (one can point to the venerable Bannister Fletcher), but one can see how Ball arrived at his version of the evolutionary nature of Roman architecture when he reveals that he has borrowed Stephen J. Gould’s famous “punctuated equilibrium” version of the scientific theory of evolution as a model (262). The Neronian period was a time when innovation ran wild, but, as in scientific evolution, it led to many dead ends. What worked well for Severus, Celer, and the other Neronian architects was consolidated by adoption and adaptation under Rabirius and the other Flavian architects. Another efflorescence of creativity under Hadrian again led to many dead ends, even as a century of exuberant late republican concrete development was followed by the comparatively conservative Augustan architecture in post and beam.
Ball has imposed clear limits on his discussion. He does not attempt to reconstruct the Domus Aurea as a living space, nor does he place it within Nero’s propagandistic or aesthetic program. For the artistic interface between the Domus Aurea and the humans who used it (especially as it intersected with Nero’s propaganda) the reader may now profitably consult Champlin’s Nero (2003). Mention of wall decoration is perfunctory, and only in service to the masonry chronology (261). The upper level gets only the scanty treatment appropriate to its scanty remains. There is nothing wrong with Ball’s selective treatment, but the buyer should have a firm idea of what she is getting. In the end, this is an important book full of good, well-reasoned ideas, sometimes pugnaciously advanced. It revolutionizes our understanding of the Domus Aurea and is an invaluable resource for researchers and teachers of Roman architecture alike.
A few typos and problems to correct in a future edition. Pg. 72, “east side of Room 56” should read “east side of Room 36”. Pg. 82, “why it is stippled in Figure 11”: I see no stippling on the feature in question, but this points up the need for larger fold-out plans in a discussion like this. Pg. 142, “it is a darker vertical strip to the left” was probably written while looking at a slide of figure 45 from the rear. The strip in figure 45 to which this description refers is on the right, and the figure corresponds in layout to the plans in the book (and indeed the caption correctly refers to the “vertical dark band on the right”). Pg. 229, for “Octagon Suit” read “Octagon Suite”. Pg. 236, for “sequenced” read “sequence”. Pg. 277 n. 2 for “perfect” read “pluperfect”.