entirely of gravels and boulders, which can only have been deposited when there was a dead level at that height across the Nile valley. All the depths of the Nile below those hills have been scoured out by the rainfall and the torrent of the stream, some miles in width, and probably one to two hundred feet in depth. And the age of this is not merely geological and beyond human interests. Man was there at this time, as his rude flint implement, river-worn and rolled, high upon the hills, now shows us. (See Chap. VI. Fig. 58.) We come down an age later. The Nile had fallen to near its present level, but still filled its whole bed to perhaps fifty feet deep. Vegetation still grew on the hills; for we find traces of man at this time, and he must have lived on something. Where he lived we can guess by the flints which he fashioned, and which the heavy rains swept away down the valleys, and bedded in the shoals of _débris_ in the reduced and shallow river. These flints are now to be picked out from the sides of later cuttings which the rain has made through its old river deposits, now high and dry in air; and it is at the mouth of the valley of the tombs of the kings at Thebes that these flints have been collected. After that, we know nothing more of man until we find that the country was in its present state,--without any rainfall for practical purposes, the hills all barren desert, the Nile only filling the bottom of its old bed for a few months of the year, and meandering the rest of the time in a channel cut in its own mud, and man cultivating the old bed of the river when it is not overflowed. The civilization that we find before us in the earliest known history appears elaborate and perfect. After that, only slow changes of fashion and taste influenced it, and but few discoveries of importance were made during thousands of years which ensued. That this civilization was imported by an incoming race seems most probable; and the dynastic Egyptians found already in the country an aboriginal population, whose features, whose beliefs, and whose customs, differed much from their own. The two races had not yet amalgamated when we first come into their presence at Medum; but soon after that all signs of difference cease.