[294] _Ibid._ vol. ii. fig. 44. Sec. 6.--_Secondary Forms._ (_Doors, windows, steles, altars, obelisks, mouldings._) We have been obliged to dwell at length on the arch and the column because those two elements of construction are of the greatest importance to all who wish to gain a true idea of Mesopotamian art and of its influence upon neighbouring peoples and over subsequent developments of architecture. On the other hand we shall have very little to say upon what, in speaking of Egyptian art, we called _secondary forms_.[295] We have already had occasion to speak of some of these, such as windows and doors. We have explained how the nature of his materials and the heat of the climate led the architect to practically suppress the former, while, on the other hand, he gave extravagant dimensions to the latter. It was to the door that the rooms had mainly to look for the light and air, with which they could not entirely dispense. We have now to give a few details as to the fashion in which these large openings were set in the walls that enframed them. As for salient decorative members--or mouldings, to give them their right name--their list is very short. We shall, however, find them in some variety in a series of little monuments that deserve, perhaps, more attention than they have yet received--we mean altars, steles, and those objects to which the name of _obelisks_ has, with some inaccuracy, been given. Some of these objects have no little grace of their own, and serve to prove that what the Chaldaeans and Assyrians lacked was neither taste nor invention, but the encouragement that the possession of a kindly material would have given to their genius. Doorways seem to have been generally crowned with a brick archivolt; round-headed doors occur oftener than any others on the bas-reliefs, but rectangular examples are not wanting (see Fig. 43). In the latter case the lintel must have been of wood, metal, or stone. Naturally the bronze and timber lintels have disappeared, while in but a single instance have the explorers found one of stone, namely that discovered by George Smith at the entrance to a hall in the palace of Sennacherib (Fig. 95). It consists of a block of richly carved limestone. Its sculptures are now much worn, but their motives and firm execution may still be admired. Two winged dragons, with long necks folded like that of a swan, face each other, the narrow space between them being occupied by a large two-handled vase. Above these there is a band of carved foliage, the details of which are lost in the shadow cast by a projecting cornice along the top of the lintel.[296] The necklace round the throat of the right-hand dragon should be noticed. It is surprising that stone lintels are so rare, especially as the corresponding piece, if we may call it so, namely, the sill or threshold, was generally of limestone or alabaster, at least in the more important and more richly-decorated rooms.