THE HADRIANIC BATHS

To create a plausible reconstruction of the Hadrian Baths at Leptis Magna by the means of a computer model.

Presentation of this reconstruction will either be by slides of ray-traced and textured computer generated images, or by using plotted perspectives of the building as an accurate underlay for 'conventional' perspective drawings.

Introduction

I chose the Hadrianic baths because although not the largest of Roman baths the Hadrianic Baths are a grand complex of buildings with reasonably varied and interesting internal volumes. Only one other reconstruction could be found, which made it seem worthwhile to study this building rather than other more documented and drawn buildings such as the Baths of Caracalla which was the subject of many Beau-Arts style drawings around the turn of this century.

The computer was chosen as the medium because of its potential to create full colour images in perspective with textures and shadows. This assignment is in part about the computers usefulness in the reconstruction of ancient monuments.

10th Century B.C.? Town founded by Phoenicians.

650-600 B.C. Evidence of a Greek colony "Lepcis".

450-350 B.C. City now appears to be a Punic city "in contact with Carthage, Greece and Southern Italy."[1]

193-46 B.C. Control of the city slowly shifts from Punic to Roman by a series of alliances and events.

23 B.C. Becomes part of the new Roman province of Africa.

1-110 A.D. City prospers under successive emperors as seen by the steady building of monuments, large public amenities etc; starting with the theatre.

119-120 "Quintus Servilius Candidus brings water into the city for the Hadrianic Baths, now under construction."[2]

126-127 Inauguration of the Hadrianic Baths.

144 As evidence of continued prosperity the Theatre Fountain was enlarged with public money; the `scaena' of the Theatre furnished with marble columns at the expense of two private citizens.

146 Birth of L. Septimius Severus at Leptis, later to become emperor of Rome and patron of the city.

193-211 Reign of L. Septimius Severus.

200-216 A period of major building, improvements to the city and its walls including additions to the baths, notably the two side baths in the Tepidarium. The Severian Bas-reliefs were carved in 203. Also there were major extensions to the harbour and the Circus was built.

216-375 Greater emphasis on fortification against inland tribes as Roman power shifts to Constantinople and the city loses status and is no longer able to market its grain or trade as effectively as it used to. The city absorbs a number of raids and plunderings.

375-378 Partial restoration of the city and citizen rights under Nicomacus Flavianus.

455 A period of Vandal opposition; the outer wall is destroyed and the wadi rises, breaks the banks of the Severian diversionary dam and flows into the harbour silting it up.

523 The city is sacked by a Berber tribe and is then abandoned by its inhabitants. (Procopius).

533 Byzantine expedition lead by Belisarius is sent by Justinian. Region returns to status of Consular Province with Leptis as its capital. Byzantines fortify the remains of the harbour and convert the remains of the Severan Basilica into a church. The rest of the city is already engulfed in sand.

643 Region is occupied by Arabs.

Time line sourced from "The Buried City"

The Reconstruction

Sources

This reconstruction of the Hadrianic Baths is largely based on three types of sources;

(i) Pictorial evidence from plans and photographs of the building's ruins.

(ii) Descriptive accounts by modern authors on the Baths in both their existing condition and in their imagined original state.

(iii) Evidence shown by contemporary buildings in other parts of the Roman empire which gives clues as to likely construction methods and spatial forms.

The first source was naturally the major one as a labelled scale plan by Bandinelli provided the layout of the complex and the major dimensions necessary for the reconstruction. The accompanying description and those by other authors, named and explained the functions of the rooms if they are known. All of the major spaces have been recognized by their size, shape and position in the complex. The precise function of a large number of ancillary rooms cannot be determined however as they lack the structural (and therefore still evident) distinction of the various bath halls, gymnasia and latrines. These rooms would have most probably housed the libraries, small meeting places and shrines that Roman bath houses of the period supported as part of their role as places of popular daily recreation.

Many (mainly black and white) photographs of the ruins as excavated exist. The monograph "The Buried City; Excavations at Leptis Magna" by Bandinelli is full of pictures as are other books on Roman North Africa and the Roman world. Naturally particular views are often repeated in all the texts and this meant that some areas of the building were substantially more documented than others.

The photographs were used to reconstruct details of portions of the building, for which the small scale plan was unsuitable or silent. The arrangement of the cold plunge bath niches in the frigidarium is the best example of this.

The lack of a reconstruction section through the building or a section through the ruins meant that heights had to be estimated from photos by comparison with known objects ie; the "28 1/2 foot high columns"[3] in the frigidarium and by examining the proportions postulated by the reconstruction drawing of the main hall by Cecil C. Briggs (1931). At best these heights are approximate and as little of the ruins is over four metres tall, the ultimate heights are conjectural. The building has lost its internal decorative claddings and as most photos are in black and white, colours and materials could only be found in descriptions.

A number of the descriptions mention the materials and the colours of the stones discovered on the site in their weathered state, though never in a systematic way or for the whole building, instead it is usually for poetic effect.

"Limestone, honey-coloured or marble veined, white against the deep blue of the sea."[4]

The resulting colour scheme in the computer is therefore largely imagined, with the exception of a few known elements. Texts also gave clues to structures and the type of vaulting over each room.

The history of Leptis appears to have been discovered largely by archaeology on the site. Dedications on monuments and erected buildings provide direct sources and dates, which seems to have allowed for accurate knowledge of the cities history, backed up by parallel knowledge of the events in the Roman world.

The third source is the general library of images of the Roman world, in which Bath houses feature strongly. Reconstructions from numerous sources show interiors of large buildings like the Baths of Caracalla and the Baths of Dioclection. Sections, perspectives and axonometrics of these buildings show atmosphere, construction and spatial forms used in by the Romans in their `Baroque' plans. The Hadrianic Baths are of equivalent age to the first large Roman baths and are of substantial size and quality, though it must remembered that Leptis was a provincial capital and that later Baths (like those above) were spatially much more complex than the Baths at Leptis with greater interpenetration of vaults and voids, more curves in the plan and were structurally more daring in their use of brick and concrete cross vaulting.

Materials and Construction

Leptis was not destroyed by a cataclysm like Pompeii but instead decayed over time and was repeatedly pillaged throughout history for building stone, columns and decorative treasures. Much of Leptis has been rebuilt this century from the rubble buried in the sand, largely under the direction of Italian archaeologists. No small objects remain although a large number of damaged statues have been recovered. Most statues have been removed to museums in Europe and recently the museum in nearby Tripolina. Copies of some statues have been installed in the ruins in their original places, perhaps order to evoke the romantic nature of the site better.

The city was largely built out of local stone of varying grades from local sources.

"Building was made considerably easier by the existence nearby(at Wadi Zennad as well as Leba itself) of excellent quarries for stone and for a grey lias limestone that acquires a fine yellow patina with time."[5]

The Hadrianic baths were the first buildings in the city to be built largely in marble for both its structure and its ornament. Several types of marbles have been described by authors including, pink `brecia' marble columns surrounding the swimming bath (or natatio), huge `cipollino' marble columns in the main frigidarium hall and black granite columns around the frigidarium plunge baths. Another marble mentioned as being used in the city was a green `brecia'. As has been mentioned much building material has been pillaged from the sites and some columns and inscriptions from the city are apparently now in Windsor Castle.

Sculpture

The baths were filled with a large amount of statuary including reproductions of Greek masterpieces, often Romanized superficially into their Latin forms where appropriate. Images of Bacchus (Dionysius) and Hercules who were patron deities for the City of Leptis Magna are of particular importance though the full Pantheon of gods appear to have been represented. Statues found include; a Mars in repose, a Venus, Hermes with Iacchus and an Apollo `Musageta' (a standing Apollo holding a Lyre).

Many authors comment on the inherently Greecian forms and proportions that infuse the art and architecture of the city.

"a city where marble gives the statues a soft outline that is still Greek, and different from the hard Roman outline."[6]

This is perhaps due to the city's Phonecian and Greek colony origins and was enhanced by the city's continued wealth at a time when ruling taste favoured Greek style.

"Emperor Hadrian the philhellene, who reintroduced the taste for Atticism even in Rome."[7]

One of the most famous statues from the baths is the image of the deified youth Antinious, who throughout the Hellenistic world, particularly the east was often combined with the figure of the youthful Apollo. In this statue the fusion is a real one as the existing Apollo figure had its face replaced with the more personalized features of Antinious. Menen[8] comments that this recycling of an old statue represents a certain lip-service by the inhabitants of Leptis to the power of Rome and its fashions as the locals appear to be unwilling to pay very much money toward such an imported icon. It none-the-less remains an excellent statue of high technical quality, which was typical of the period.

The other major type of statues in the baths are celebratory statues of local patricians. These are usually full figure and are clothed, full figure portraits in the Roman realist mould and depicting a variety notables from young male magistrates to elderly matriarchs. Miscellaneous fragments also remain of satyrs, torsos of athletes, dolphins with putto and other decorative motifs which would have completed the opulent effect of the baths.

The Effects of the Computer on Reconstruction

Computer Modelling

The process of the computer reconstruction is important as it naturally will affect the style of the resulting graphics and so I have explained it as follows;

A plan of the baths was `scanned'[9] into the computer. This formed a `bitmap' picture of black and white dots. This picture was then traced to form a plan composed of polygonal shapes which could then be transferred to the modelling program and re-scaled to the final size.

The modelling program `Microstation'[10] always works in three dimensions and at full size, ie; scale 1:1. The model is then viewed at a much smaller scale on the screen of the computer. There was insufficient information in the actual plan itself as it had none of the vertical dimensions or descriptions necessary to make a model. Vaults, arches and niches have to be described numerically and accurately using the various `tools' supplied by the Microstation program. This meant in practice that each wall had to be first drawn in elevation and then given thickness, columns `revolved' as if on a lathe and all the parts then moved into their final position. `Complex shapes' like the bath pools, corinthian column capitals and vaults had to be made up of a number of separate pieces which were then copied and mirrored to form larger assemblies.

Computer Rendering

Once the model was nearing completion it was possible to transfer it yet again to another program `ModelView' to apply the various textures to the building elements and to view the model in perspective easily and fluidly. In this program the model sits in the centre of a large void, the `ground' has to be part of the model as a large baseboard. An `environment cube' completely surrounds the void and onto the faces of this cube images, usually of the sky, are `pasted'. This provides the background to the generated images.

This program was then left to `generate' each final `rendered' image, with `textures' and shadows cast. This is a lengthy and complex process which takes time for the computer to complete. The amount of time varies depending on;

(a) The type of rendering chosen. ModelView has two versions; the first `quicktracing' shows textures and a basic level of lighting. The second `raytracing' also calculates shadows, reflections and transparency. The raytracing option may take ten to twenty times the time of a quicktrace.

(b) The complexity of the model being rendered. A model with many curved surfaces or with mirrors or transparent/translucent surfaces will take longer as more variables have to be considered at each `test'.

(c) The size of the image being generated. A small picture (80 x 100mm) will render sixteen times faster than a large picture (320 x 400mm).

(d) The number of light sources the computer has to allow for. The minimum is one source plus the `ambient'[11] lighting. The `sun' is one such source placed at infinity with respect to the model. Having two light sources plus the ambient, doubles the time required, three triples it etc.

(e) An `anti-aliased'[12] image which appears smoother and finer will take about four times longer than an ordinary image.

The final images is is then displayed on the computer screen and can then be photographed using a camera and tripod to produce colour slides or photographic prints. Slide-makers are on the market which transfer the electronic data directly onto the slide film with much greater defintion, colour brilliance and without the curved effect apparent when taking a photograph of the screen. It is possible to print out the picture on a `laser-printer' to produce individual images on paper in black and white. These are however of a poorer quality of resolution.

The lighting effects possible on the `Intergraph' computer have limitations and do not always appear naturalistic. This is most apparent in interior views where the lighting often appears flat and unconvincing. The `ray-traced' sciagraphy is very hard edged and does not show the soft edges with umbra and penumbra which are common in interiors. Also although `specular reflections' off objects are visible as `highlights' on a surface but they do not in turn light other objects as happens in reality. This lack of interaction between lit or glowing objects prevents the computer from showing wall washes and varigated shadow effects which would be more natural in appearance and significantly lighten the interior of a room. Also the sky is not a light soure and so no diffuse light comes in through windows facing away from the sun despite the sky outside seeming to be bright, making a discordinant effect. The reason why the sky cannot be a light source is that only infinitely small point light sources, not tubes or diffuse plates, are possible in the ModelView program.

Exterior views however appear more realistic as bright sunlight tends to cast hard shadows of high contrast and the diffuse effects of light, although still extant, are of less visual strength than the sunlight. This suits the computers lighting bias better and the results are correspondingly more convincing. Also exterior views can be made convincing with only one light source, the sun, and are thus quicker to render.

The viewing camera is easily tilted up or down, causing the perspectives generated by the computer to be often in full three point perspective. This is unlike drawn perspectives where only two point perspective is usual, the difference can be disconcerting if the viwer is used to tradional perspective drawing sand many photgraphs of built buildings are deliberately taken to avoid the third vanishing point by means of a tilt plane camera and this is a facility provided in ModelView, although there is a coresponding trade-off in the distortion of the image near the boundries of the picture plane, which is particularly noticable with circles; becoming distended ellipses. The wider use of computers will see an increase in the use of perspectives in architectual rendering instead of the the currently common axonometrics as the computer can draw curves, circles and complicated shapes with comparitive ease. This is already noticable in the renderings of new projects, particularly `high-tech' works, where computer draw `plots'[13] of highly complex spaceframe vaults are used as underdrawings for perspectives or presented directly as computer renderings.

This method of reconstruction by computer modelling has the advantage that any number of drawings can be generated from the one model from any direction; inside, unusual angles, orthographic or perspective views and under differing lighting conditions. These views may be altered easily and the computer left to `generate' the new view overnight. Modifications to the model are often (but not always) easy to achieve. The main disadvantage of this approach is in fact the its very versatility of the viewing which tempts the user to make many changes which slows the process by; (a) demanding that the entire model be sufficiently complete in form and detail to allow inspection from every angle, rather than the set view of one traditional illustrative perspective, and (b) every change requires a re-rendering of the view to see its full effect, which is another nights work for the computer.

The choice of model is also important as the computer is more able to do certain things, for instance mass copying of parts. In this case the Hadrianic Baths were mirrored down the central axis and so only half the model needed to be constructed. The `size' of the model, how much memory it consumes in the computer, is related more to the level of complexity of the model, how detailed, how unique,how many, how complex the individual geometries of the parts are than the absolute size of the building being modelled. For this reason the model of the Baths is more detailed in some parts which I thought would appear more dramatic in the final renderings, in order to save both my construction time and memory on the computer.[14]

The computer has advantages and disadvantages compared with other reconstruction methods, the most important being that a choice of viewpoints is possible once the model is entered into the computer but the building of the model takes considerable time and may not poduce the effects, particularly atmospheric that the user may want.

Bibliography

Bandinelli, R. B.

"The Buried City; Excavations at Leptis Magna"; Introduction by Ranuccio Bianchi Bandinelli. Texts by E. V. Caffarelli and G. Caputo.

Weidenfeld and Nicolson, London 1967.

Main resource for accurate plans. Most complete photographic depiction and an excellent text containing a general historic summary and site description for Leptis Magna. As this book was written by researchers closely involved with the archaeological work at Leptis this book is perhaps the closest source after the monuments themselves.

Lyttelton, Margret

"Baroque Architecture in Classical Antiquity" ,London 1974.

Large and thorough disscussion of the rise and form of Ancient `Baroque' architecture from its origins in the Hellenistic east, its precence in Pompeian wall frescos and its gradual expansion through the Roman world in the first century A.D. Leptis is disscussed and illustrated in some detail although the baths are not mentioned specifically as the author focuses on buildings of the Severan period.

Matthews, Kenneth, D.

"Cities in the Sand; Leptis Magna and Sabratha in Roman Africa";

Philadelphia 1963.

Similar in age and format to the book by Bandinelli with text and black and white photos but is slightly shorter and discusses Sabratha as well as Leptis in its length.

Menen, A.

"Cities in the Sand" London 1972.

Descriptive passage on the actual use of the Baths by the population. Menen is very interested in Roman custom, tastes and society but tends to have a slightly moral attitude to his comments on these things.

Neary, P.

"Discoveries in Tripoli" The Architectural Review, Vol 57, May 1925, London.

Contemporary account of the excavations underway in 1925 with photos of the partially excavated bathhouse and description of the statues and halls.

Wheeler, Mortimer

"Roman Africa in Colour" London 1966.

Coffee table book with a comparatively small number of large format colour pictures. The accompanying text contains a brief description of the major parts of the city with an emphasis perhaps on evoking the romantic quality of the ruins.

Wheeler, Mortimer

"Roman Art and Architecture" London 1964.

Extensive introduction to the history and forms of Roman art and architecture. The city of Leptis is treated in depth as an example of a Roman Empire city and includes plans after Bandinelli as well as a chapter on Roman baths as a type, illustrated with photos and reconstructions of famous Roman baths.

Notes

[2] Ibid pg 58. (back)

[3] V. Caffarelli and G. Caputo; "The Buried City" pg 99. (back)

[4] Ibid pg 49 (back)

[5] V. Caffarelli and G. Caputo; "The Buried City" pg 17. (back)

[6] V. Caffarelli and G. Caputo; "The Buried City" pg 49. (back)

[7] Ibid pg 49. (back)

[8] Menen, A; "Cities in the Sand" (back)

[9] Words in inverted commas are common computer terminology. (back)

[10] `Microstation' and `ModelView' is a proprietry trade name. (back)

[11] Ambient light refers to a general level of brightness which determines how dark the darkest shadows will be. A high ambient light level results in washed-out or over-exposed image while a very low level makes any shadow areas completely black. (back)

[12] `Anti-aliasing' is a process where the computer does extra calculations to decide a better colour and tonal value for each `pixil' dot on the screen. This averaging process has the effect of smudging and smoothing the image, removing the staircase-like effect common to computer pictures. (back)

[13] A `plot' is a line drawing by the computer in pen or pencil on paper using a `plotter', a drawing machine. (back)

[14] The larger the model the longer it takes to manipulate objects as the computer has to sort through a greater number of parts to select the those being manipulated, this slows the process of modelling proportionally and can be overcome with more powerful computers (with which people naturally make larger and more complex models!). (back)