for a stroke of piston of six feet. On each side of the cylinder three lugs are to be cast, projecting six inches, to be ten inches broad by two inches thick, each lug to be supported on the upper sides by a bracket at each end. The top of the lugs to be on a line with the center of the cylinder. The cylinder to be placed on an angle of fifteen degrees. On one side of the cylinder, at each end, is to be cast a supply nozzle with an opening of nine inches by four inches, having a flange fifteen inches square by one and one-fourth inches thick, for receiving steam, and on the other side two similar nozzles for the exhaust; openings to be ten inches by four inches, and flanges sixteen inches by fifteen inches. These flanges to be planed on the face, and drilled to receive 7/8 bolts every three inches. The under side of the lugs to be also planed, and the outer ones to be drilled for 1 3/4-inch bolts in each. The cylinder covers to be one and three-fourths inches thick, and sunk into the end of cylinder about four inches and recessed, where the supply and exhaust openings come to allow the steam to act freely. They are to be faced to a joint where they meet the cylinder ends, and drilled to receive bolts one and one-eighth inches diameter five inches apart. The forward cover to have a stuffing box seven inches deep, bushed with a brass bush at the bottom. The flange to be two and one-fourth inches thick, the follower to enter three inches. The flange to be one and one-half inches thick, and to be furnished with three 1 1/8-inch bolts for screwing down.

Piston.- To be of cast-iron, with a space of four inches for packing. The packing consists of two rings; the outer one of brass, three-fourths of an inch thick, and in three widths, to contain recesses to be filled with Babbitt metal, and sawed obliquely through in one place; the inside one of metal, one- fourth of an inch thick, and the whole depth between head and follower. This ring is also sawed obliquely across in one place. All the rings to be carefully scraped on each other and on follower and piston. Behind the metal ring, and bearing against it the whole depth, are five cast-steel springs, backed out with 7/8-inch bolts and check nuts, in the usual way. Piston head and follower to be one inch, metal round eye, one and three-fourth inches, this eye to be one recessed for collar of piston, and accurately bored to fit its taper. The follower is held to its place by five 1-inch t-headed bolts and nuts, to be sunk into follower. The piston rod to be made of the best fagoted wrought- iron, four inches diameter, about nine feet two inches long, to be tapered and fitted into piston and secured by a collar and key-key two and three-fourths inches by seven-eights inch; also, to be provided with a backing-off key. The crosshead to be of cast-iron, the socket into which the rod is fixed with a key, three and one-half inches by three-fourths of an inch, to be ten inches long by ten inches diameter over the largest part. From end of socket to center of wrist fourteen and one-fourth inches. Wrist five and one-half inches diameter to five inches wide. Space between forks six and three-fourths inches. Section of fork, five and one-half inches deep by an average breadth of four inches. The jaws are bolted to the crosshead with three 7/8-inch bolt, and nuts to be one and three-fourths inches thick. The gibs to be brass filled with Babbitt metal, presenting a surface to the slides of nine inches long by three inches wide. War to be adjusted in the usual way. The supply side pipes to be in sections, seven and three-fourths inches by five and three- fourths inches, with a thickness of metal of one inch. At each end is a chamber to receive a lift valve, six and one-half inches diameter in the clear, metal of seat