with them. In those the pipes were made entirely of castiron, and I don't know that any of them ever gave out, although I have not had much experience with them. But I think there is one thing very certain; that you will find cast-iron will last better as a flue heater than any other material you can get. If the water is cold that is pumped through pipe, it seems to condense the acids from the products of the combustion on the outside of the pipes which will dissolve wrought iron in a very short time. REULEAUX'S KINEMATIC MODELS. BY PROF J. BURKITT WEBB, OF CORNELL UNIVERSITY, ITHACA, N. Y. In this paper Professor Webb explained the improvements made by Professor Reuleaux in the science of mechanism, and illustrated his remarks by a selection of models, copied from the celebrated collection of the Royal Polytechnic School at Berlin, and borrowed from the cabinets of Cornell University for this purpose. 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 a 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 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 act ing 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 a 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 |