An interesting letter and accompanying map, from Kosciuszko, relating to these works, is here published for the first time: "WEST POINT, 25TH APRIL, 1779. "SIR: I send you a ruff map of West Point, with indication as you desire from me, about the Public Buildings, and the Works. "The Carpenters Compliend about the provision, that he have not enof; he beg your honor to allow them more bred. a House full of Ammunition. b The Barracks. c The Carpenter's House. d The Commissary House. e For the Fourage. f The Huts. g The Read House. h Baker's House. i Provision House. k Small Commissary House. l Smock House. m The Barracks. n The Steble, o Of the Artellery Officer's House p Artellery Barracks. q Greaton's Battery. r Chain Battery begun last summer. s Redoubt for fivety men begun last Summer. t Redoubt for fivety men begun last Summer. u Guard House. w Guard House not covered. x Point of (Projected) Block House with Bumprove for fivety men. y Swamps. Your Most Humble Servant (Signed) THAD KOSCIUSZKO Col. The Honorable Major General MCDOUGALL, Peekskill." [Illustration: MAP OF WEST POINT] While these land defenses were planned and situated to aid in controling the passage of the Hudson, a formidable obstruction was made by stretching across the river at its narrowest point, a boom of huge short logs, united at the ends by chains so as to resemble a rope ladder, and a few yards higher up, an immense chain was buoyed up on logs, extending across from one shore to the other. This chain was made by Noble, Townsend & Company, at the Stirling Iron Works, yet in operation near the Sloatsburg Station, on the Erie Railroad, about twenty-five miles from West Point. It was carried in pieces to New Windsor on wagons, put together there, and floated down the river into its position, in April, 1778. A portion of the chain is preserved, and is to be seen lying in a grove on the north side of the Plain. The links are made of two-inch bar iron, and each weighs about 120 pounds. The entire chain weighed 186 tons.