Fig. 70.—Double-faced wall.
We cannot, however, affirm that the number of supports is invariably decided by the length of the architraves, or of the roofing stones. Some very long monoliths are supported at regular intervals, lest they should break with their own weight or with that put upon them. The walls, architraves, and vertical supports are always far stronger than the mere weight of the roof would require.
Figs. 71, 72.—Elements of the portico.
The following woodcut shows the arrangement of supports, architraves and roof. These simple arrangements constitute a complete system of construction which, belonging exclusively to Egypt, has had results upon which we cannot too strongly insist. Both roof and architraves being horizontal, all the pressure upon the walls is vertical. There is no force tending to thrust the walls outwards nor to affect the immobility of the supports.
Fig. 73.—Egyptian construction, epitomized by Ch. Chipiez.
Consequently, if the proportions of the vertical and horizontal elements of a building, that is to say, its sections, have been skilfully determined, there is in the building itself no latent cause of disruption; its equilibrium is perfect, and can only be destroyed by external physical causes, by long exposure to the weather, by earthquakes, or by the hand of man.[104]
We see then that the first impression caused by the external lines of the architectural monuments of Egypt is confirmed and explained by further study. They are built, as said the Pharaohs themselves, "for eternity." Stability, in a word, in its highest and most simple form is the distinguishing characteristic, the true originality, of Egyptian architecture.