We must here call attention to the importance of a bas-relief belonging to the curious series of carved pictures in which Sennacherib caused the erection of his palace at Nineveh to be commemorated. Look well at this group of buildings, which seems to rise upon a platform at the foot of a hill shaded with cypresses and fruit-laden vines (see Fig. 43). The buildings on the right have flat roofs, those on the left, and they seem the most important, have, some hemispherical cupolas, and some tall domes approaching cones in shape. These same forms are still in use over all that country, not only for public buildings like baths and mosques, but even here and there for the humblest domestic structures. Travellers have been often surprised at encountering, in many of the villages of Upper Syria and Mesopotamia, peasants' houses with sugar-loaf roofs like these.[163]
We need not here go further into details upon this point. In these general and introductory remarks we have endeavoured to point out as concisely as possible how the salient characteristics of Assyrian architecture are to be explained by the configuration of the country, by the nature of the materials at hand, and by the climate with which the architect had to reckon. It was to these conditions that the originality of the system was due; that the solids were so greatly in excess over the voids, and the lateral over the vertical measurements of a building. In this latter respect the buildings of Mesopotamia leave those of all other countries, even of Egypt, far behind. They were carried, too, to an extraordinary height without any effort to give the upper part greater lightness than the substructure; both were equally solid and massive. Finally, the nature of the elements of which Mesopotamian architects could dispose was such that the desire for elegance and beauty had to be satisfied by a superficial system of decoration, by paint and carved slabs laid on to the surface of the walls. Beauty unadorned was beyond their reach, and their works may be compared to women whose attractions lie in the richness of their dress and the multitude of their jewels.
NOTES
[147] Oppert (Expédition scientifique, vol. i. p. 86) gives a description of one of these storms that he encountered in the neighbourhood of Bagdad on the 26th of May.
[148] Layard, Nineveh and its Remains, vol. ii. p. 119. When one of these mounds is attacked from the top, the excavators must work downwards until they come to this paved platform. As soon as it is reached no greater depth need be attempted; all attention is then given to driving lateral trenches in every direction. In Assyria the mass of crude bricks sometimes rests upon a core of rock which has been utilized to save time and labour (Layard, Discoveries, &c., p. 219).
[149] See Herodotus, i. 181-184; and Diodorus, ii. 9.
[150] By such means M. Oppert arrives at a height of 250 Babylonian feet, or about 262 feet English for the monument now represented by the mound in the neighbourhood of Babylon known as Birs-Nimroud. Expédition scientifique de Mésopotamie, vol. i. pp. 205-209, and plate 8.
[151] Ὁμολογειται δ' ὑψηλον γεγενησθαι καθ' ὑπερβολην.—Diodorus, ii. 9, 4.
[152] The mound called Babil on the site of Babylon (Plate I. and Fig. 37) is now about 135 feet high, but the Birs-Nimroud, the highest of these ruins, has still an elevation of not less than 220 feet (Layard, Discoveries, p. 495).
[153] See Layard's account of his excavation in the interior of the pyramidal ruin occupying a part of the platform which now surmounts the mound of Nimroud. From two sides trenches were cut to the centre; neither of them encountered a void of any kind (Nineveh and its Remains, vol. ii. p. 107). At a later period further trenches were cut and the rest of the building explored (Discoveries, pp. 123-129). The only void of which any trace could be found was a narrow, vaulted gallery, about 100 feet long, 6 wide, and 12 high. It was closed at both ends, and appeared never to have had any means of access from without.
[154] See Lenormant, Histoire Ancienne, vol. ii. pp. 228 and 233. Translations of several texts in which these restorations are spoken of are here given.
[155] του κατασκευασματος δια του χρονου διαπεπτωκοτος (ii. 9, 4).
[156] Strabo, xvi. 5.
[157] Diodorus, after describing the treasures of the temple, confines himself to saying generally, "all this was afterwards spoiled by the king of Persia" (ii. 9, 19).
[158] According to the personal experience of M. Place, the ancient arrangements were more suited to the climate of this country than the modern ones that have taken their place. The overpowering heat from which the inhabitants of modern Mossoul suffer so greatly is largely owing to the unintelligent employment of stone and plaster in the construction of dwellings. During his stay in that town the thermometer sometimes rose, in his apartments, to 51° Centigrade (90° Fahrenheit). The mean temperature of a summer's day was from 40° to 42° Centigrade (from 72° to about 76° Fahrenheit).
[159] See Layard, Monuments of Nineveh, 2nd series, plates 21 and 40.
[160] The serdab is a kind of cellar, the walls and floor of which are drenched periodically with water, which, by its evaporation, lowers the temperature by several degrees.
[161] The town represented on the sculptured slab here reproduced is not Assyrian but Phœnician; it affords data, however, which may be legitimately used in the restoration of the upper part of an Assyrian palace. We can hardly believe that the Mesopotamian artists, in illustrating the wars of the Assyrian kings, copied servilely the real features of the conquered towns. They had no sketches by "special artists" to guide their chisels. They were told that a successful campaign had been fought in the marshes of the lower Euphrates, or in some country covered with forests of date trees, and these they had no difficulty in representing because they had examples before their eyes; so too, when buildings were in question, we may fairly conclude that they borrowed their motives from the architecture with which they were familiar.
[162] See the History of Art in Ancient Egypt, vol. ii. pp. 77-84.
[163] Layard, Discoveries, p. 112; Geo. Smith, Assyrian Discoveries, p. 341.
As might have been expected nothing that can be called a structure of dressed stone has been discovered in Chaldæa;[164] in Assyria alone have some examples been found. Of these the most interesting, and the most carefully studied and described are the walls of Sargon's palace at Khorsabad.
Even there stone was only employed to case the walls in which the mound was inclosed—a cuirass of large blocks carefully dressed and fixed seemed to give solidity to the mass, and at the same time we know by the arrangement of the blocks that the outward appearance of the wall was by no means lost sight of. All those of a single course were of one height but of different depths and widths, and the arrangement followed a regular order like that shown in Fig. 46. Their external face was carefully dressed.[165]
| Fig. 44.—Plan of angle, Khorsabad; from Place. Fig. 44.—Plan of angle, Khorsabad; from Place. | Fig. 45.—Section of wall through AB in Fig. 44; from Place. Fig. 45.—Section of wall through AB in Fig. 44; from Place. |
The courses consist, on plan, of "stretchers" and "headers." We borrow from Place the plan of an angle (Fig. 44), a section (Fig. 45), and an elevation (Fig. 46). Courses are always horizontal and joints properly bound. The freestone blocks at the foot of the wall are very large. The stretchers are six feet eight inches thick, the same wide, and nine feet long. They weigh about twenty-three tons. It is astonishing to find the Assyrians, who were very rapid builders, choosing such heavy and unmanageable materials.
The supporting wall became gradually thinner towards the top, each course being slightly set back from the one below it on the inner face (see Fig. 45). This arrangement is general with these retaining-walls. The average diminution is from seven to ten feet at the base, to from three to six at the top.
The constructor showed no less skill in the use he made of his stretchers and headers. They not only gave him an opportunity of safely diminishing the weight of his structure and economising his materials, they afforded a ready means of adapting his wall exactly to the work it had to do. The headers penetrated farther into the crude mass within than the stretchers, and gave to the junction of the two surfaces a solidity similar to that derived by a wall from its through stones or perpenders.
In describing this wall, M. Place also calls attention to the care with which the angles are built. "The first course," he says, "is composed of three 'headers' with their shortest side outwards and their length engaged in the mass behind. Two of these stones lie parallel to each other, the third crosses their inner extremities."[166] Thanks to this ingenious arrangement, the weakest and most exposed part of the wall is capable of resisting any attack.
The surface in contact with the core of crude brick was only roughly dressed, by which means additional cohesion was given to the junction of the two materials; but the other sides were carefully worked and squared and fixed in place by simple juxtaposition. The architect calculated upon sufficient solidity being given by the mere weight of the stones and the perfection of their surfaces.[167]
The total height of this Khorsabad wall was sixty feet—nine feet for the foundations, forty-six for the retaining-wall, and five for the parapet, for the wall did not stop at the level of the roofs. A row of battlements was thought necessary both as a slight fortification and as an ornament.[168] These were finished at the top with open crenellations in brick, along the base of which ran apparently a frieze of painted rosettes. A reference to our Fig. 47 will explain all these arrangements better than words. It is a bird's-eye view in perspective of the south-western part of the palace. The vertical sections on the right of the engraving show how the stones were bonded to the crude brick. The crenellations are omitted here, but they may be seen in place on the left.
The great size of the stones and the regularity of the masonry, the height of the wall and the long line of battlements with which it was crowned, the contrast between the brilliant whiteness of its main surface and the bright colours of the painted frieze that, we have supposed, defined its summit—all this made up a composition simple enough, but by no means devoid of beauty and grandeur.
In the enceinte surrounding the town, stone was also employed, but in a rather different fashion. It was used to give strength to the foot of the wall, which consisted of a limestone plinth nearly four feet high, surmounted by a mass of crude brick, rising to a total height of about forty-four feet. Its thickness was eighty feet. The bed of stone upon which the brick rested was made up of two retaining walls with a core of rubble. In the former, large blocks, carefully dressed and fixed, were used; in the latter, pieces of broken stone thrown together pell-mell, except towards the top, where they were so placed as to present a smooth surface, upon which the first courses of brick could safely rest.[169]
When Xenophon crossed Assyria with the "ten thousand," he noticed this method of constructing city walls, but in all the enceintes that attracted his attention, the height of the plinth was much greater than that of Khorsabad. At Larissa it was twenty, and at Mespila fifty feet, or respectively a fifth and a third of the total height of the walls.[170] These figures can only be looked upon as approximate. The Greeks did not amuse themselves, we may be sure, with measuring the monuments they encountered on their march, even if Tissaphernes gave them time. But we may fairly conclude from this evidence that in some of the Assyrian town-walls the proportion between the plinth and the superstructure was very different from what it is in the only example that has come down to us.
At Khorsabad, then, stone played a much more important part in the palace wall than in that of the town, but even in the latter position it is used with skill and in no inconsiderable quantity; on the other hand, it is only employed in the interior of the palace for paving, for lining walls, for the bases, shafts and capitals of columns, and such minor purposes. In the only palace that has been completely excavated, that of Sargon at Khorsabad, everything is built of brick. Layard alone speaks of a stone-built chamber in the palace of Sennacherib at Kouyundjik, but he gives no details.
It would seem as if the Assyrians were content with showing themselves passed-masters in the art of dressing and fixing stone, and, that proof given, had never cared to make use of the material in the main structures of their buildings. Like the Chaldæans, they preferred brick, into the management of which, however, they introduced certain modifications of their own. The crude brick of Nineveh and its neighbourhood was used while damp, and, when put in place, did not greatly differ from pisé.[171] Spread out in wide horizontal courses, the slabs of soft clay adhered one to another by their plasticity, through the effect of the water with which they were impregnated and that of the pressure exercised by the courses above.[172] The building was thus, in effect, nothing but a single huge block. Take it as a whole, put aside certain parts, such as the doorways and drains, that were constructed on rather different principles, shut your eyes to the merely decorative additions, and you will have a huge mass of kneaded earth which might have been shaped by giants in a colossal mould.
The masons of Babylon and of other southern cities made a much more extensive use of burnt brick than those of the north. In Assyria the masses of pisé have as a rule no other covering than the slabs of alabaster and limestone, and above, a thin layer of stucco. In Chaldæa the crude walls of the houses and towers were cuirassed with those excellent burnt bricks which the inhabitants of Bagdad and Hillah carry off to this day for use in their modern habitations.[173] The crude bricks used behind this protecting epidermis have not lost their individuality, as at Nineveh they seem to have been used only after complete dessication. They are of course much more friable than those burnt in the kiln; when they are deprived of their cuirass and exposed to the weather they return slowly to the condition of dust, and their remains are seen in the sloping mounds that hide the foot of every ancient ruin (see Fig. 48), and yet if you penetrate into the interior of a mass built of these bricks, you will easily distinguish the courses, and in some instances the bricks have sufficient solidity to allow of their being moved and detached one from another. They are, in fact, bricks, and not pisé. But in Chaldæa, as in Assyria, the mounds upon which the great buildings were raised are not always of crude brick. They are sometimes made by inclosing a large space by four brick walls, and filling it with earth and the various débris left by previous buildings.[174] Our remarks upon construction must be understood as applying to the buildings themselves, and not to the artificial hills upon which they stood.
The Assyrians seem never to have used anything analogous to our mortar or cement in fixing their materials. On the comparatively rare occasions when they employed stone they were content with dressing their blocks with great care and putting them in absolute juxtaposition with one another. When they used crude brick, sufficient adherence was insured by the moisture left in the clay, and by its natural properties. Even when they used burnt or well dried bricks they took no great care to give them a cohesion that would last, ordinary clay mixed with water and a little straw, was their only cement.[175] Even in our own day the masons and bricklayers of Mossoul and Bagdad are content with the same simple materials, and their structures have no great solidity in consequence.
In Chaldæa, at least in certain times and at certain places, construction was more careful. In the ruin known as Babil, a ruin that represents one of the principal monuments of ancient Babylon, there is nothing between the bricks but earth that must have been placed there in the condition of mud.[176] These bricks may be detached almost without effort. It is quite otherwise with the two other ruins in the same neighbourhood, called respectively Kasr and Birs-Nimroud. Their bricks are held together by an excellent mortar of lime, and cannot be separated without breaking.[177] Elsewhere, at Mugheir for instance, the mortar is composed of lime and ashes.[178]
Finally, the soil of Mesopotamia furnished, and still furnishes, a kind of natural mortar in the bituminous fountains that spring through the soil at more than one point between Mossoul and Bagdad.[179] It is hardly ever used in these days except in boatbuilding, for coating the planks and caulking. In ancient times its employment was very general in the more carefully constructed buildings, and, as it was found neither in Greece nor Syria, it made a great impression upon travellers from those countries. They noted it as one of the characteristics of Chaldæan civilization. In the Biblical account of the Tower of Babel we are told: "They had brick for stone, and slime had they for mortar."[180] Herodotus lays stress upon the same detail in his description of the way in which the walls of Babylon were built: "As they dug the ditches they converted the excavated earth into bricks, and when they had enough, they burnt them in the kiln. Finally, for mortar they used hot bitumen, and at every thirty courses of bricks they put a layer of reeds interlaced."[181]
Those walls have long ago disappeared. For many centuries their ruins afforded building materials for the inhabitants of the cities that have succeeded each other upon and around the site of ancient Babylon, and now their lines are only to be faintly traced in slight undulations of the ground, which are here and there hardly distinguishable from the banks that bordered the canals. But in those deserts of Lower Chaldæa, where the nomad tent is now almost the only dwelling, structures have been found but little damaged, in which layers of reeds placed at certain intervals among the bricks may be easily distinguished. As a rule three or four layers are strewn one upon the other, the rushes in one being at right angles to those above and below it. Here and there the stalks may still be seen standing out from the wall.[182] Fragments of bitumen are everywhere to be picked up among the débris about these buildings, upon which it must have been used for mortar. It never seems to have been employed, however, over the whole of a building, but only in those parts where more than the ordinary cohesive power was required. Thus, at Warka, in the ruin called Bouvariia, the buttresses that stand out from the main building are of large burnt bricks set in thick beds of bitumen, the whole forming such a solid body that a pickaxe has great difficulty in making any impression upon it.[183]
Travellers have also found traces of the same use of bitumen in the ruins of Babylon. It seems to have been in less frequent employment in Assyria. It has there been found only under the two layers of bricks that constitute the ordinary pavement of roofs, courts, and chambers. The architect no doubt introduced this coat of asphalte for two purposes—partly to give solidity to the pavement, partly to keep down the wet and to force the water in the soil to flow off through its appointed channels. A layer of the same kind was also spread under the drains.[184]
In spite of all their precautions time and experience compelled the inhabitants of Mesopotamia to recognize the danger of crude brick as a building material; they endeavoured, therefore, to supplement its strength with huge buttresses. Wherever the ruins have still preserved some of their shape, we can trace, almost without exception, the presence of these supports, and, as a rule, they are better and more carefully built than the structures whose walls they sustain. Their existence has been affirmed by every traveller who has explored the ruins of Chaldæa,[185] and in Assyria they are also to be found, especially in front of the fine retaining wall that helps to support the platform on which the palace of Sargon was built.[186] The architect counted upon the weight of his building, and upon these ponderous buttresses, to give it a firm foundation and to maintain the equilibrium of its materials. As a rule there were no foundations, as we understand the word. At Abou-Sharein, in Chaldæa, the monument described by Taylor and the brick pavement that surrounds it are both placed upon the sand.[187] Botta noticed something of the same kind in connection with the palace walls at Khorsabad: "They rest," he says, "upon the very bricks of the mound without the intervention of any plinth or other kind of solid foundation, so that here and there they have sunk below the original level of the platform upon which they are placed."[188]
This was not due to negligence, for in other respects these structures betray a painstaking desire to insure the stability of the work, and no little skill in the selection of means. Thus the Chaldæan architect pierced his crude brick masses with numerous narrow tunnels, or ventilating pipes, through which the warm and desiccating air of a Mesopotamian summer could be brought into contact with every part, and the slight remains of moisture still left in the bricks when fixed could be gradually carried off. These shafts have been found in the ruins of Babylon and of other Chaldæan cities.[189] Nothing of the kind has been discovered in Assyria, and for a very simple reason. It would have been impossible to preserve them in the soft paste, the kind of pisé, we have described.
Another thing that had to be carefully provided for was the discharge of the rain water which, unless it had proper channels of escape, would filter through the cracks and crevices of the brick and set up a rapid process of disintegration. In the Assyrian palaces we find, therefore, that the pavements of the flat roofs of the courtyards and open halls had a decided slope, and that the rain water was thus conducted to scuppers, through which it fell into runnels communicating with a main drain, from which it was finally discharged into the nearest river.
It rained less in Chaldæa than in Assyria. But we may fairly conclude that the Chaldæan architects were as careful as their northern rivals to provide such safeguards as those we have described; but their buildings are now in such a condition that no definite traces of them are to be distinguished. On the other hand, the ruins in Lower Chaldæa prove that even in the most ancient times the constructor had then the same object in view; but the means of which he made use were much more simple, although contrived with no little ingenuity. We shall here epitomize what we have learnt from one of those few observers to whom we owe all our knowledge of the earliest Chaldæan civilization.
Mr. J. E. Taylor, British vice-consul at Bassorah, explored not a few of the mounds in the immediate neighbourhood of the Persian Gulf which mark the sites of the burying places belonging to the most ancient cities of Chaldæa.
The summits of these mounds are paved with burnt brick; their mass consists of heaped up coffins separated from one another by divisions of the same material. To insure the preservation of the bodies and of the objects buried with them liquids of every kind had to be provided with a ready means of escape. The structures were pierced, therefore, with a vast number of vertical drains. Long conduits of terra-cotta (see Fig. 49) stretched from the paved summit, upon which they opened with very narrow mouths, to the base. They were composed of tubes, each about two feet long and eighteen inches in diameter. In some cases there are as many as forty of these one upon another. They are held together by thin coats of bitumen, and in order to give them greater strength their sides are slightly concave. Their interiors are filled in with fragments of broken pottery, which gave considerable support while they in no way hindered the passage of the water. These potsherds are even placed around the outsides of the tubes, so that the latter are nowhere in contact with the brick; they have a certain amount of play, and with the tubes which they encase they form a series of shafts, like chimneys, measuring about four feet square. Every precaution was taken to carry off the water left by the storms. They were not contented with the small opening at the head of each tube. The whole of its dome-shaped top was pierced with small holes, that made it a kind of cullender. Either through this or through the interstices of the potsherd packing, all the moisture that escaped the central opening would find a safe passage to the level of the ground, whence, no doubt, it would be carried off to the streams in conduits now hidden by the mass of débris round the foot of every mound.
That these arrangements were well adapted to their purpose has been proved by the result. Thanks to the drains we have described, these sepulchral mounds have remained perfectly dry to the present day. Not only the coffins, with the objects in metal or terra-cotta they contained, but even the skeletons themselves have been preserved intact. A touch will reduce the latter to powder, but on the first opening of their coffins they look as if time had had no effect upon their substance.[190]
By these details we may see how far the art of the constructor was pushed in the early centuries of the Chaldæan monarchy. They excite a strong desire in us to discover the internal arrangements of his buildings, the method by which access was given or forbidden to those chambers of the Babylonian temples and houses whose magnificence has been celebrated by every writer that saw them before their ruin. Unhappily nothing has come down to us of the monuments of Chaldæa, and especially of those of Babylon, but their basements and the central masses of the staged towers. The Assyrian palaces are indeed in a better state of preservation, but even in their case we ask many questions to which no certain answer is forthcoming.
The great difficulty in all our researches and attempts at restoration, is caused by the complete absence of any satisfactory evidence as to the nature of the roofs that covered rooms, either small or large. In most cases the walls are only standing to a height of from ten to fifteen feet;[191] in no instance has a wall with its summit still in place been discovered.
The cut on the opposite page (Fig. 50) gives a fair idea of what a Ninevite building looks like after the excavators have finished their work. It is a view in perspective of one of the gates of Sargon's city: the walls are eighty-eight feet thick, to which the buttresses add another ten feet; their average height is from about twenty-five to thirty feet, high enough to allow the archway by which the city was entered to remain intact. This is quite an exception. In no part of the palace is there anything to correspond to this happy find of M. Place—any evidence by which we can decide the forms of Assyrian doorways. The walls are always from about twelve to twenty-eight feet in thickness (see Fig. 46.) Rooms are rectangular, sometimes square, but more often so long as to be galleries rather than rooms in the ordinary sense of the word.
The way in which these rooms were covered in has been much discussed. Sir Henry Layard believes only in flat roofs, similar to those of modern houses in Mossoul and the neighbouring villages. He tells us that he never came upon the slightest trace of a vault, while in almost every room that he excavated he found wood ashes and carbonized timber.[192] He is convinced that the destruction of several of these buildings was due in the first instance to fire. Several pieces of sculpture, those from the palace of Sennacherib, for instance, may be quoted, which when found were black with soot. They look like castings in relief that have been long fixed at the back of a fire-place.
Long and narrow rooms may have been roofed with beams of palm or poplar resting upon the summits of the walls. As for the large halls, in the centre they would be open to the sky, while around the opening would run a portico, similar to that of a Roman atrium, whose sloping roof would protect the reliefs with which the walls were ornamented.[193]
As to this, however, doubt had already been expressed by an attentive and judicial observer like Loftus; who thought that the arch had played a very important part in the architecture of Mesopotamia.[194] As he very justly remarked, the conditions were rather different from those that obtained in the maritime and mountainous provinces of Persia; there was no breeze from the gulf or from the summits of snowy mountains, to which every facility for blowing through their houses and cooling their heated chambers had to be given; the problem to be solved was how best to oppose an impenetrable shield against a daily and long continued heat that would otherwise have been unbearable. Now it is clear that a vault with its great powers of resistance would have been far better fitted to support a roof whose thickness should be in some reasonable proportion to the massive walls, than a ceiling of bad timber. In our day the mosques, the baths, and many of the private houses of Mossoul and Bagdad have dome-shaped roofs. Without going as far as Mesopotamia, the traveller in Syria may see how intelligently, even in the least important towns, the native builder has employed a small dome built upon a square, to obtain a strong and solid dwelling entirely suited to the climate, a dwelling that should be warm in winter and cool in summer.
We must also point out that the state in which the interiors of rooms are found by explorers, is more consistent with the hypothesis of a domed roof than with any other. They are covered to a depth of from fifteen to twenty feet with heaps of débris, reaching up to the top of the walls, so far as the latter remain standing.[195] This rubbish consists of brick-earth mixed with broken bricks, and pieces of stucco. Granting wooden roofs, how is such an accumulation to be accounted for? Roofs supported by beams laid across from one wall to the other, could never have safely upheld any great weight. They must have been thin and comparatively useless as a defence against the sun of Mesopotamia. On the other hand if we assume that vaults of pisé were the chosen coverings, all the rest follows easily. They could support the flat roof with ease, and the whole upper structure could be made of sufficient thickness to exclude both the heat and the rain, while the present appearance of the ruins is naturally accounted for.
Those who have lived in the East, those, even, who have extended a visit to Athens as far as Eleusis or Megara, must have stretched themselves, more than once, under the stars, and, on the flat roofs of their temporary resting-places, sought that rest that was not to be found in the hot and narrow chambers within. They must then have noticed, as I have more than once, a large stone cylinder in one corner. In Greece and Asia Minor, it will be in most cases a "drum" from some antique column, or a funerary cippus, abstracted by the peasantry from some neighbouring ruin. This morsel of Paros or Pentelic has to perform the office of a roller. When some heavy fall of rain by wetting and softening the upper surface of the terrace, gives an opportunity for repairing the ravages of a long drought, the stone is taken backwards and forwards over the yielding pisé. It closes the cracks, kills the weeds that if left to themselves would soon transform the roof into a field, and makes the surface as firm as a threshing-floor.
The roofs of Assyrian buildings must have required the same kind of treatment, and we know that in the present day it is actually practised. M. Place mentions rollers of limestone, weighing from two to three hundredweight, pierced at each end with a square hole into which wooden spindles were inserted to facilitate their management.[196] A certain number of these rollers were found within the chambers, into which they must have fallen with the roofs. As soon as the terraces ceased to receive the care necessary for keeping down the weeds and shrubs and keeping out the water, the process of disintegration must have been rapid. The rains would soon convert cracks into gaping breaches, and at the end of a few years, every storm would bring down a part of the roof. A century would be enough to destroy the vaults, and with them the upper parts of the walls to which they were closely allied by the skill of the constructor. The disappearance of the archivolts and the great heaps of débris are thus accounted for. The roof materials were too soft, however, to damage in their fall the figures in high relief or in the round that decorated the chambers beneath, or the carved slabs with which their walls were lined. In spreading itself about these sculptures and burying them out of sight and memory, the soft clay served posterity more efficiently than the most careful of packers.
Among the first observers to suspect the truth as to the use of the vault in Mesopotamia, were Eugène Flandin, who helped Botta to excavate the palace of Sargon,[197] and Felix Thomas,[198] the colleague of M. Place. The reasons by which M. Thomas was led to the conclusion that the rooms in the Ninevite palaces were vaulted, are thus given by M. Place, who may be considered his mouthpiece.[199]
He does not deny that some of the Khorsabad reliefs bear the marks of fire, but he affirms, and that after the experience of four digging campaigns, that the conflagration was much less general than might be supposed from the statements of some travellers. He failed to discover the slightest trace of fire in the hundred and eighty-four rooms and twenty-eight courts that he excavated. The marvellous preservation of the reliefs in many of the halls is inconsistent, in his opinion, with the supposition that the palace was destroyed by fire; and if we renounce that supposition the mere action of time is insufficient to account for the disappearance of such an extent of timber roofing, for here and there, especially near the doorways, pieces of broken beams and door panels have been found. "The wood is not all in such condition as the incorruptible cedar of the gilded palm-trees, but wherever it certainly existed, traces of it may be pointed out. In advanced decomposition it is no more consistent than powder, it may be picked up and thrown aside, leaving a faithful cast of the beam or post to which it belonged in the more tenacious clay."