A water tax is imposed on every building supplied, which is graduated according to the size of the structure. A one story of sixteen feet width is taxed $4, a five-story with a width of twenty-five feet, $12 per annum. In manufactories, the Commissioners design to collect one cent for every one hundred gallons used, as nearly as may be. The water tax during 1868 amounted to $1,232,404.95, and since its introduction in 1842 to over $18,000,000. In November, 1868, the water was shut off for five days, for the inspection and repairing of the aqueduct. During the suspension of the flow of water, the reservoirs were reduced over nine feet, reminding us that if the supply should he cut off, our hydrants would fail in about fifteen days. The Croton ranks among the purest streams of the world. Its waters are collected in a district of 352 square miles. Mountains and hills of azoic gneiss receive the rainfall, which is filtered by the pure silicious sands and gravels, to gush out in numberless springs and brooks, which flow in sparkling transparency to .the lake, the great reservoir. Here the sediments are mainly deposited, before the aqueduct is reached. A stone wall has been thrown around the lake, to isolate the drainage from the surrounding farms. A careful analysis of the water shows that the amount of impurity during a whole summer amounted to but 4.45 grains per gallon, or 7.63 parts in 100,000.

Dublin is the only city in Europe supplied with water as pure as the Croton, and Boston, Philadelphia, and Trenton, only in America. Nine old wells were filled and covered in 1868, though two or three hundred still exist. Their waters are greatly polluted, and are fruitful sources of disease, the only remedy—filling them all—should be promptly attended to.

By means of a new purchase of water-right in the spring of 1870, the volume of water during the dry season has been much increased, and the city saved from any anxiety in relation to the supply of this indispensable element.