The rooms in Sargon’s palace are nearly all rectangular in shape, sometimes square, but generally very long in proportion to their breadth. The walls of the rooms were phenomenally thick and vary from twelve to twenty-eight feet. The roofs of these long chambers must have either been vaulted, or else constructed of timber-beams, though the former would have been the more serviceable in a climate characterized by extreme heat on the one hand and extreme cold on the other, for the thick vaulting would alike avert the scorching rays of the summer’s sun and the penetrating cold of a rigorous winter, while the discovery of an enormous quantity of broken bricks, débris and rubble, and the corresponding absence of any trace of wood in the excavated rooms supports the theory that the roofs were made of clay rather than of wood; and lastly, the only wood easily procurable would seemingly have been quite inadequate to support the strain of a superimposed flat roof of mud. Victor Place furthermore actually discovered the remains of vaults which had collapsed, while the extensive use of the arch both in the city walls of Khorsabad as well as in the drainage of the palace furnishes an additional argument and increases the probability of the theory yet the more. The disappearance of any trace of wood in the rooms themselves might have been explained by the frailty and non-enduring character of that material, but near the doorways, which obviously could not have been formed of clay, or stone, fragments of wood as well as door panels are said to have been found, and without doubt, had the ceilings of the rooms been made of wood also, similar evidence of the fact would be forthcoming. Place further alludes to the discovery of rollers made of limestone in some of the chambers: these rollers may have been used to flatten and solidify the pisé-roofs after a downpour of rain, and thereby been the means of preventing the dissolution and general collapse of this integral part of the structure. But these clay roofs however unsatisfactory they may have been in days gone by from the architectural standpoint, have proved of incalculable value to the archæologist of to-day, for to the softness of the material of which they were composed is due the perfect preservation of the sculptures and statues which they were destined to entomb for so long a period.