AMERICAN INSTITUTE. 657 



Tlie President then called up the regular subject — " Cut-off 

 on Steam Engines." 



Mr. S, D. Williams, Civil Engineer, spoke of the advantages 

 of tiie variable cut-off, which is regulated by a governor of the 

 steam, admitting more or less, automatically, and by the same 

 mechaiiiciil management the fires in the furnace and the pressure 

 of the steam may lilvewise be governed, and far more accurately 

 than by engineers. Let steam into the cylinder one-half, let that 

 then act by its expansion, &c. 



Mr. J. K. Fisher explained the useof the link motion in locomo- 

 tive engines as applied to Stevens' cut-off, showing its easy action 

 and its value in preserving the machine from injurious shocks- 

 Engineer Copeland made that application. 



Mr. Stetson had remarked the application of cam-motion to 

 govern cut-offs in our western States. 



Mr. Leonard — The steam engine having become the great mo- 

 tive power of the world, it has called forth the genius of mechanics 

 and inventors for the better and more economical working of its 

 parts. The great variety of plans for cutting off the steam in the 

 cylinder in order to realize the advantage of the expansion of the 

 steam, and the great variety and forms of valves, size of ports, 

 &c , is occupying the attention of the public. There is evidently 

 a great want of method in working both steam boilers and steam 

 engines, and a lack of knowledge with builders of engines in ad- 

 justing all the parts to give the greatest amount of power with 

 the least amount of fuel; I, therefore, have applied a dynamometer 

 to the steam cylinder, which has a small cylinder, say from one 

 to three inches diameter, a piston vibrating from one and a half 

 to two inches, held against the pressure of steam by a spring equal 

 to the power applied; a rod attached to said piston, connected 

 with a traverse wheel, which rises from the centre of a disk- wheel 

 (against which it presses) in proportion to tlie power of steam in 

 the cylinder, connected with which I have clockwork that sums 

 up on a dial the power applied to the piston, less the hack pressure, 

 giving for any desired period the actual horse power of steam used. 

 I have a pencil attached to this machine, and a slide board con- 

 nected with the cross head, on which a paper may be placed to 

 [Am. Inst.1 42 



