ciently dry to retain its place, the plate is turned down and leveled by a number of small pieces of iron in its final position, a space of

HALF ELEVATION.

FIG. 3.

at least one-quarter of an inch being left between the under side of the brick-work in the bed-plate and the top of the foundation,

which space is run full of a strong cement grout as soon as the holding-down bolts are in place; thus insuring for the bed-plate a perfect bearing at every point of its area. The construction of the

crank pillow-block presents some peculiarities; as will be seen in the drawing, Fig. 4, the pillow-block is held in position as against vertical displacement by two holding-down bolts, which pass

B

through its body in close proximity to the "brasses," the nuts of these bolts have a bearing upon the upper surface of the base of the pillow-block, and are covered by its cap; the block being secured against horizontal displacement by means of a key at each end. In this connection I will say that in some machinery which I have erected since the design of this engine, I have secured pillow-blocks against lateral displacement by running the space between the pillow-block and the key-lug full of Babbitt metal, and as the result of three years of experience of its use on a line of heavy shafting, I have no hesitation in recommending it as in every way satisfactory.

The frame of the engine has nothing especially novel in its details; it is composed of four similar castings fitted and bolted together, and provided with feet at their lower extremities, through which the holding-down bolts at the corners of the bed-plate pass, and they are also secured to the bed-plate independently of the holding-down bolts by a number of tap bolts, as will be seen in the elevations, Fig. 1 and 2. The four main castings of the frame are steadied and stiffened by four curved braces, which are fastened to them near the middle. The cross-head guides, which are simple. rectangular troughs, in which the cross-head blocks slide, are secured to two of these braces as well as to the frame of the engine by turned and fitted bolts, the guides being planed in between vertical lugs on the inside of the braces, and all contact surface between guides and frame being also planed together.

To insure proper distance and parallelism between the under side of the feet and the top of the engine frame, after the frame and its braces were fitted together the whole was put in a lathe and the bottoms of the feet and the top of the frame were turned off. The steam cylinder is of the ordinary construction such as is in common use in the majority of tug engines; its bottom being cast solid with its body, save that a sufficient opening is left through its centre to accommodate the boring bar. This opening is closed by the stuffing box (figures 5 and 6), which presents one constructive feature which is believed to be novel, and which is certainly very satisfactory in its practical operation: I refer to the means by which the water which follows the piston rod through the stuffing box is trapped out and prevented from running over cross head and connecting rod. This is accomplished as follows: The stuffing box itself is made of greater length than usual and the packing is divided into two parts, separated by what may with propriety be