THE NEW CROTON DAM.

THE NEW CROTON DAM.

After fourteen years of steady work and an expense of $7,700,000, the new Croton dam was pronounced completed on the evening of Saturday, March to, or. perhaps, more properly on the next day (Sunday), when the contractors and engineers made a final trip over the construction railway. From below the dam they passed over the highway which will span its crest up to the quarries, seven miles away, and then returned to the dam. The rails were then torn up, and the dam was dotx-. Water is filling the enormous basin it makes of the valley and hillsides of the Croton river, and early next month is expected to reach the level of the top of the spillway. When it does so. there will he 34,000,000,000 gallons of water added to the supply for NewYork city. The dam is larger than the three great dams of F.urope combined. They are the Vyrny dam in England, the Furens in France, and the Gilepoe in Belgium. In Egypt the Assuan dam, built to control the irrigating floods of the Nile, is longer than the Croton dam, but it is more of a dyke than a dam. and is only seventy feet in height, against 301 feet of the Croton’s wall. The following figures are interesting: Cost of dam, $7,700,000; time of construction, years, fourteen; adds to the city’s water supply, gallons, 34,000,000,000,000; total length, feet, 2,400; length of main dam, feet, 1,400; length of spillway, 1,000; length of bridge span over outlet for water below spillway, feet, 200; height from base of foundation to main dam top, feet, 301; height from mean high tide level to top of main dam, feet, 216; height of main dam top above spillway top, feet, sixteen; depth of w’ater behind dam when flowing over spillway, feet, 160; depth of water now in dam, feet ninetyfive; thickness of masonry at base, feet, 216; thickness at top of main dam, feet, twenty-one; thickness at spillway top, feet, ten; length of lake formed by dam, miles, nineteen and two-thirds; Extreme width of lake (Hunter’s brook), miles, two; constructor of dam—James S.-Coleman and his associates, J. Breuchard and B. F. Coleman The spillway shows some special characteristics. While the stone steps below its top are rough and uneven, the work there is, if anything, more carefully done than in the main dam. The rough steps are made of great blocks of stone from two to five tons in .weight, and they are joined with the finest precision. When the floods of early spring bring a great volume of water over the dam, it will he full of blocks of ice, many tons in’ weight, which must be crushed as they drop from step to step below. To meet their shock and to pulverise them the big stones were put in the face of the spillway. When the water has risen to the top of the spillway and is flowing over it, its surface will be sixteen feet below the level of the highway which crosses the main dam and the bridge. The water will be 160 feet in depth at the dam. There are over no feet of water there now, and it is rising every day faster since the late heavy snow falls. ,.

THE NEW CROTON DAM.

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THE NEW CROTON DAM.

The illustration below shows the face of the new Croton dam and spillway under construction, omitted from the description of the great work, given in a recent issue of this journal. The view of the lower masonry work, printed in that number, showed the nature and extent of the work from the base of the dam.