THE NILE IN HARNESS of her history, and it is only in comparatively recent years that man has attempted to control the old river and by a system of dams hold back the waters and let them out over the farms as needed. To master the Nile has cost many millions of dollars which have gone into building the great barrages in the lower river, and more important than all, the mighty dam away up here at Aswan.

Egypt is almost rainless and the Nile gives both land and people their food and drink. I have already described some of the wonders of the stream and what it does for Egypt. It rises in Lake Victoria, in Central Africa, and drops a distance greater than the altitude of the highest of the Alleghanies before it flows into the Mediterranean Sea. In the upper part of its course it is known as the White Nile, and this should be called the main stream of the river. At Khartum, thirteen hundred and fifty miles from the Mediterranean, the Blue Nile, which rises in the Abyssinian Mountains, comes in, while about one hundred and forty miles farther north the Atbara, or Black Nile, which is also from Abyssinia, joins the main stream. From the mouth of the Atbara to the sea there is not a tributary of any kind connected with the river. It ploughs its way through the desert valley, in which it has built up Egypt, narrowing and widening, until a few miles below Cairo, where it divides into two great branches and flows off into the sea.

The volume of the Nile is enormous. At flood times, a billion tons of water go by at Aswan every day. The river then rises twenty-five feet at Cairo, thirty-eight feet at Old Thebes, and almost fifty feet at the first cataract, where I now am. There is so much water that no dam could hold it, hence all of these great works had to be 129