The lakes of Westchester, like the hills and streams, boast no features of exceptional interest, but are strictly in keeping with the quiet beauty of the general landscape. The largest, as already mentioned, isCroton Lake, entirely artificial; and we have also seen that

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several of the natural lakes have been utilized for purposes of water supply. Lake Waccabuc, in the Town of Lewisboro, has, since 1870, been connected with the Croton system. It covers over two hundred acres, and is very deep and pure. In the Town of Poundridge several

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ponds have been artificially joined to one another, forming a handsome body of water, called Trinity Lake, a mile and a quarter long, which supplies the City of Stamford, Conn. A dam twenty feet high has been erected across its outlet. Other lakes of local importance and interest are Peach Lake, on the Putnam County border; Mohegan and Mohansic lakes, in Yorktown; Valhalla Lake (through which the Bronx River flows), between Mount Pleasant and North Castle; Rye Lake, near the Connecticut line; Byram Lake, in Bedford and North Castle, the feeder of the Byram River, and Cross Pond (100 acres) in Poundridge. The rocks of Westchester County consist mainly of gneiss and micaschist of many dissimilar varieties, and white crystalline limestone with thin interlying beds of serpentine, all of ancient origin and entirely devoid of fossils. Professor Ralph S. Tarr, of Cornell University, in a recent series of papers1 on the geology of New York State, embodying the latest investigations and conclusions on the subject, assigns to the southern angle of the State, including Westchester County, the name of the " Gneissic Highland Province." This province, he says, is of complex structure, and one in which, in its main and most typical part, the rocks are very much folded and disturbed metamorphic strata of ancient date.