53 i TRANSACTIONS OF THE AMERICAN INSTITUTE. 



that the recess n' in the valve in cylinder a is just ready to lap the channel 

 e' and cover the opening- h\ thus admitting- steam at once to the cylinder 6 

 above its piston g. This channel will be kept open until the piston in a has 

 completed its stroke and returned back to the half stroke, for then the 

 piston g will have completed its stroke and be ready to return ; it must, 

 therefore, be allov7ed to exhaust its steam. The recess /?i' will now have 

 come to the opening i^ and channel f\ thus at once exhausting the steam, 

 for the two half strokes of the piston in a are just equal to the whole 

 stroke of g. The piston g acts in like manner for the valve for the cylinder 

 c. The piston in the latter is returning for a new stroke and is accordingly 

 exhausting its steam; the channel / is accordingly in connection with the 

 escape passage i through the recess m, as siiown, and the same operation 

 takes place for the cylinders c and d. Thus it will be understood that in 

 each cylinder there is contained, beside the piston, a valve operated directly 

 by the piston to admit and exhaust the steam to and for the next cylinder. 

 The valve j is for the purpose of starting, stopping, and reversing the 

 engines. When this valve is drawn so that the steam admitted at k passes 

 from the top of the valve into k^, the steam will be exhausted through /' by 

 the under side of the valve, and vice versa, the crank turning according to 

 the direction the steam takes in these two pipes. 



Figs. 3 and 4 are enlarged' views of the crank, showing the manner of 

 attaching the connecting rods. As the cylinders all lie in one plane, the 

 ends of the connecting rods all meet and abnt upon the crank pin, some 

 device must be resorted to to keep them there. The end of each of the 

 connecting rods terminates in a crosspiece q^ on the connecting rod q and 

 r' on the opposite rod ?■; each crosspiece on its face is hollowed out to fit 

 the crank pin and' press against it. These faces are less than a quarter of 

 a circle, in order to leave room for the vibration of the rods as seen in figs. 

 1 and 3. The connecting rods are kept pressing np to the crank pin by 

 means of two rings which embrace the whole four of the cross arms, one 

 ring being between the crank and the connecting rods, as seen at s, fig. 4, 

 and the other above the rods aod extending out to the end of the crank pin 

 as at s', figs. 3 and 4. These Vings are kept in place by a cap t, fig. 4, 

 screwed to the end of the crank pin p. The operation is as follows: Steam 

 being admitted throug k, the valve j is drawn, so as to allow it to flow 

 through k^, whence it will pass by the branch pipes to each of the cylinders, 

 abed. The piston g is just at the end of its return stroke and in the 

 position ready to receive steam. The position of the recess n' of the valve 

 in cylinder a is just at the edge of the port or opening into the channel 

 e' and likewise at the steam aperture /i'. So soon as the said recess passes 

 these openings, a continuous ciiarinel is at once formed, and the steam flows 

 through into the cylinder b above the piston, and accordingly drives the 

 latter toward the crank. At the same time that the piston in b is receiving 

 the effect of the steam ac^mitted through the cylinder c, the piston in b is 

 performing the office of regulating the flow of steam into and from c, the 

 "piston in this latter cylinder having performed its stroke is exhausting its 

 steam, and it will be seen by the direction of the arrow flowing back 

 through f m and i to the final discharge I. The lower face of the narrow 

 channel o' forms a "cut off" by lapping over the port in e' as soon as the 



