The aqueduct has tifteen arches, eight of which are on the river bottom. They are each eighty feet in width and one hundred feet high above flood tide. The seven shore arches have each fifty feet span. To reach the foundation of each pier a coffer-dam was built and pumped out until the sand bottom was excavated and the solid rock laid bare or a firm pile foundation prepared on which the masonry was laid. Above the roof of the arches the huge iron pipes which carry the water are fixed on wooden sills, and above them is the foot-way of the bridge. As the elevation of the arches is less than that of the Croton Aqueduct, a system of syphons and gate houses receives the water at the east side and discharges it at the west. The aqueduct was in working order on July 4, 1842, but the bridge was not completed until six years and six months afterward. Its extreme height above the river surface is one hundred and fourteen feet, two inches. It is constructed of sound gneiss, equal in durability to granite. The cost of the aqueduct was $8,575,000, including purchases of land and extinguishment of riparian rights. This figure was within five per cent, of the estimates of Chief Engineer Jervis. To it, however, must be added $1,800,000, the cost of distributing pipes, the interest, the expense of placing the loans, etc., which bring the total up to $12,500,000.'

- Proceedings of Board of Supervisors N. Y. Co., April, 1856. 3 Schrampke's account of the Croton Aqueduct.