BALANCED VERTICAL ENGINES.

BY

W. F. DURFEE, BRIDGEPORT, CONN.

Ar the Altoona meeting of this Society, during the discussion of the paper of Prof. Robinson, there was a question asked relative to the possibility of balancing the moving parts of vertical direct acting engines, which failed to elicit a very satisfactory reply, the general impression being that it was a difficult problem, which might be, but never had been, satisfactorily solved by so arranging masses of metal that they moved in opposition to, and therefore balanced the reciprocating parts of the engine. It is the purpose of this paper to explain another method of balancing the reciprocating parts of direct acting vertical engines, for which the writer was granted Letters Patent, March 21, 1871, and which has been applied with success to engines designed by himself and others. The first engine to which the method of balancing about to be described was applied, was designed and erected by the writer in the years 1868-9, for driving a train of twelve-inch rolls in the works of the American Silver Steel Co., at Bridgeport, Conn., and I have selected the drawings of this engine to illustrate this paper, in which I will describe in addition to the peculiar method of balancing the moving parts, some other details of construction which I believe to be of value. The engine, as will be seen from the elevations, Fig. 1 and 2, is of the direct acting inverted cylinder type, and, in its general form and framework, presents no very conspicuous novelty, save that above the cylinder is seen what appears to be a dome surmounted by a cupola; to this feature I shall presently ask your more particular attention.

The diameter of cylinder and stroke of piston are each twenty (20) inches. The revolutions per minute when the train was run on small rods are two hundred and twenty-five (225), giving piston speed of seven hundred and fifty (750) feet. The bed plate is six feet square and six inches in depth, and is strengthened by a number of ribs as shown in the drawing, Fig. 3. Before this plate is placed in position on the foundation it is turned on edge and filled with brick-work laid in cement mortar, and when this is suffi

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

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