CAIRO TO KISUMU the Nile on both sides, and holding back a portion of its mighty waters. It is a huge granite barrier a mile and a quarter long. There is now a roadway guarded by walls on its top, and there is a miniature railway, the cars of which are pushed by men from one end to the other. The dam serves as a bridge as well, and donkeys, camels, and men are allowed to pass over it from bank to bank. I crossed on the car at a cost of twenty-five cents, my motive power being two Arab boys who trotted behind.

As I came over, I stopped from time to time to examine the construction. The dam is made of big blocks of red granite as fine as that of any tombstone in the United States. They are beautifully cut, and fitted as closely as the walls of a palace. On the upper side or south face the wall is perpendicular, forming a straight up-and-down bar¬ rier against the waters of the Nile. I climbed down a ladder on that side at one place almost to the river, and could see that the blocks are fitted so closely that the ce¬ ment does not show. The masonry seems almost one solid stone throughout, with the exception of where the great sluices are cut, to allow the river to flow through at the times of the flood, and as the floods subside to shut back the waters to form the reservoir for the dry season.

There are one hundred and eighty of these sluice gates in the dam, each of which has steel doors that can be raised or lowered to allow the whole river to flow through or to hold back as much or as little as the engineers will. The dam is thus a great stone wall pierced by these gates.

The Nile never flows over the top of the dam, but al¬ ways through the gates and the canal at one side. When the gates are closed during the dry season, enough water is held back by this structure of steel and granite to form a 132