History of Sanitation

22 HISTORY OF SANITATION Aqueduct of Segovia, Spain The aqueduct of Segovia, Spain, is one of the most perfect and magnificent works of the kind remaining. It is built without mortar, is entirely of stone and of great solidity. The piers are 8 feet wide by n feet deep, and where the aqueduct approaches the city it attains a height of about loo feet. This aqueduct is over 2,400 feet long, is built in two tiers of arches and although almost eighteen hundred years old, still supplies water to the city. Of the 109 arches, however, 30 are of modern construction, being reproductions of the ancient arches. The constructive details of these old water courses are as interesting as are their general design. At the mouth of each aqueduct there generally was con- structed a reservoir in which to collect water from the springs or streams that supplied it, and in which impurities could settle before the clarified water was deliv- ered into the channel. The water channel was usually- formed either of stone or brick coated on the inside with cement to make it water-tight. It was arched over on top, and at certain intervals vent holes were provided through