History of Sanitation

HISTORY OF SANITATION 11 weight of bucket and water. This permitted its use for many hours at a time, when raising water for irrigation without greatly fatiguing the operator. The most ingenious and highly involved form of ancient water-raising machine was a water-wheel. The method of operating a water-wheel de- pended much on the region where used. In Egypt, along the Nile, oxen were employed for this pur- pose. In China, coolies were found more satisfactory even in raising large quantities of water for irrigation purposes, which they did by walking a simple form of treadmill on the outer edges of the water-wheel. The Water Carrier with Goat-skin Bag Romans, slow at originating, but, like the Japanese, quick to recognize the value of anything new and adapt it to their purposes, borrowed the idea of the water-wheel from the Greeks or Egyptians, but made it automatic when used in streams and rivers by adding paddles that dipped into the running water and were moved by the current of the stream. Water-wheels operated by oxen were in use at Cairo up to the twelfth century, where they raised water verti- cally a distance of 80 feet from the Nile to an aqueduct that supplied the citadel of Cairo. Our present elaborate system of water distribution was of humble origin. It was not a rapid growth, but a gradual evolution. Its four principal stages were: First, distribu- tion from natural sources by water carriers; second, aque- ducts conveying water to communities where a system of sub-conduits or aqueducts conveyed the water from the main aqueduct to reservoirs at different points in a city; third, a system of distributing mains through which water was furnished to householders at certain hours only during the day; and fourth, our present system of continuous sup- ply at all hours of the day and night. In the first stages