It will thus be seen that during the Ancient Empire the lighter forms of architecture were far in advance of that which made use of stone. It possessed a richness and variety of its own, which were rendered possible by the comparative ease with which wood and metal could be manipulated, an ease which gradually led the artist onwards to the invention of forms conspicuous for their playful originality and their singular diversity. As for the quadrangular pier, with which the stone architecture of the Ancient Empire was contented, we are assured that it had its origin in the rock-cut tombs. In the oldest works of the kind in Egypt, the funerary grottos of Memphis, "these piers (we are told) owe their existence to the natural desire to cause the light from without to penetrate to a second or even to a third chamber. In order to obtain this result, openings were made in the front wall on each side of the door, and the parts of the rock which were left for support became for that reason objects of care, and finally took the form of piers. The rock over these piers was the prototype of the architrave."[91] [91] EBERS, _Ægypten_, vol. ii., p. 186. All this passage of Ebers is, however, nothing more than an epitome of a paper by LEPSIUS, entitled: _Ueber einige Ægyptische Kunstformen und ihre Entwickelung_ (in the _Transactions of the Berlin Academy_, 1871, 4to). This paper contains many just observations and ingenious notions; but, to our mind it is over systematized, and its theories cannot all be accepted. It may be so. But, on the other hand, the pier of dressed stone may have had a still more simple origin. It may have resulted from the obvious requirements of construction. As soon as wooden buildings began to be supplemented by work in stone, it became necessary to find supports strong enough for the weight of stone roofs. Nothing could be more natural than to take a block of stone as it came from the quarry, and to set it up on end. In course of time its faces would be dressed and its section accommodated to a square, for the love of symmetry is innate in man. The pier may also be seen foreshadowed in the squared beams of that closed form of wooden architecture which has been already noticed. We see, then, that the earliest Egyptian art of which we have any remains comprised the principal elements of which later architects made use. But it is among the ruins of the great monuments constructed during the Theban supremacy that we must attempt to form an exhaustive list of their architectural forms, and to show how the genius of the race, obeying that mysterious law which governs all organic development, arrived at the complete realization of the ideal towards which it had been advancing through so many centuries. At Thebes alone can the architectural genius of the Egyptians be judged. GENERAL TYPES OF SUPPORTS.