208 HISTORY OF ARCHITECTURE. Part I. either in tombs, Avliere the rock formed an immovable abutment ; or in pyramids and buildings, where the mass immensely overpowered the thrust ; or underground, where the superincumbent earth prevented movement. They seem also to have used flat segmental arches of brickwork between the rows of massive architraves which they placed on their jnllars ; and as all these abutted one another, like the arches of a bridge, except the external ones, which were sufliciently supported by the massive walls, the mode of construction was a sound one. This is exactly that which we have re-introduced during the last 30 years, in consequence of the application of cast-iron beams, between which flat segmental ai-chcs of brick are thrown, when we desii-e to introduce a moi'c solid and fire-proof construction than is possible with wood only. In tlieir use of the arch, as in everything else, the building science of the Egyptians seems to have been governed by the soundest prin. ciples and the most perfect knowledge of what was judicious and expedient, and what should be avoided. Many of their smaller edifices have no doubt perished from the scarcity of wood forcing the builders to em])loy brick arches, but they wisely avoided the use of these in all their larger monuments — in all, in fact, which they wished should endure to the latest posterity ~
