one and one-fourth inches thick. The opening to admit the steam into the cylinder to be nine inches by four inches, to be constructed in the usual way, with a flange to fit the corresponding one on the cylinder. On each end, on a horizontal line, a projecting arm, two inches thick, well supported with a bracket, carries the column for the lever that lifts the valve; one block is cast for a seat carrying to other rock shaft, as well as a branch with a flange around it, on which is bolted the throttle-valve chamber. The faces of all these flanges to be planed, and on a horizontal line, for all the valves are to be so arranged as to lift perpendicularly and seat horizontally; an internal flange goes around each valve chamber on the steam pipe, two and one-half inches wise, one and one-fourth inches thick, on to which is bolted the covers with six 3/4-inch bolts and nuts, finished. The covers of finished cast-iron one and one-eighth inches thick, with a stuffing box three inches deep; the follower to screw down one and one-half inches, and this to be done by two 3/4-inch finished studs and nuts. The valves are to be what are called relief valves (i. e., a smaller valve on to and lifting the larger one). The supply valve is six and one-half inches in diameter, in the clear one and one-half inches, of cast-iron, with three projections three-fourths of an inch square and two and one-fourth inches long, to keep it steady in the seat. Into the top of this valve, at points equally distant, are screwed three wrought-iron studs seven-eighths of an inch in diameter, two and five-eights inches long, between shoulders, with a nut of the upper end. A triangular piece of finished wrought-iron, one inch thick, with a hole one and one-eight inches in diameter in the center for the valve stem to pass through, with a hole in each angle to take in the stud, to which it is firmly secured by the nuts. The small valve, three and one-fourth inches in the clear, seats upon the large one; it is cast-iron, in two parts; the valve having three short projections to kept it in its seat, and the back recessed to receive half the spherical end of stem, the cover being similarly recessed with a hole one and one-eighth inches diameter for the stem to pass through, and with this in its place they are both riveted together with three 3/8-inch rivets of soft iron. This valve is so thick, to fill the space, two and five-sixteenths inches between the tops of the large valve and the under side of the triangular piece of iron within one-fourth of an inch of the top, consequently it allows the small valve to open that distance and let steam into the cylinder before the large one is unseated. The exhaust pipe is in sections, eight and one-fourth inches by six and one-fourth inches, with a thickness of metal of three-fourths of an inch. At each end is a chamber to receive a valve seven and one-half inches diameter in the clear. Seat one and one-fourth inches thick, openings for exhaust ten and one-half by four inches, with flanges projecting, arms, brackets, block, and seat, with branch for exhaust pipe-relief valves-lifting and seating in every way similar to those for the supply pipe except that the large valve is to be seven and one-half inches in the clear, and the smaller ones three and three-fourths inches.

Columns for levers, four in number, to be about thirteen and one- half inches long from base to center, of finished wrought-iron, one end passing through the projection on side pipe, and secured by a nut one and one-fourth inches deep by two and one-fourth inches broad; base of column, three and three-eighths inches diameter; neck, three inches diameter; top, where lever works through, four