Bethlehem Paper - Notes on the Geology of the Tilly Foster Ore-Body, Putnam County, N. Y

The Tilly Foster iron-mine is situated in the southeastern part of Putnam County, New York, about fifty miles north of New York City, on the line of the New York City and Northern Railroad. There are a number of deposits of magnetite scattered throughout the county, the most important being those known as the Tilly Foster, the Mahopac, and the deposits of the Croton Magnetic Ore Company. (See the paper of Mr. Wendt, Transactions, xiii., 478.)