Description of Mr. Perkins^ New Steam-Engine* 1 1§ 



at both ends, with the exception of the five openings for 

 tubes, shewn in the figure. The generator is placed verti- 

 cally in a cylindrical furnace EF, whose chimney is G, the 

 heat being sustained by a pair of bellows, H, wrought by 

 the engine, and conveying its blast in the direction IK to F. 

 A heat of from 400° to 450° of Fahrenheit is thus applied 

 to the generator, which is entirely filled with water. The 

 valves in the tubes m, n, which are steel cylinders working 

 in hollow steel-pipes, are loaded, the one with 37, and the 

 other with 35 atmospheres ; so that none of them can rise 

 till the heat creates a force greater than the least of these 

 weights. 



Let us now suppose, that, by means of the compressing 

 pump L. whose handle Mis wrought by the engine, water 

 is forced into the generator; this opens the valve above n, 

 loaded with 35 atmospheres, and instantly a portion of the 

 heated and compressed water flashes out in the form of 

 steam of high elasticity, and of a temperature of 420°; and 

 communicating by the steam pipe 2, 2, 2. with the valve 

 box V, it enters the cylinder PP, lying horizontally, and 

 gives motion to its piston PQ, which perfarms 200 strokes 

 in a minute, and drives a crank R, which gives a rotatory 

 motion to a fly wheel, as seen in the figure*. When the 

 eduction-valve is opened, the steam, after having produ- 

 ced its stroke, is carried by the eduction-pipe 3, 3, 3, into 

 the condenser STXV, where it is condensed into water at 

 a temperature of about 320°, and under a pressure of 5 at- 

 mospheres ; fiom thence, by the pipe 6, 6, 6, it is drawn in- 

 to the pump L, whence it is forced along the pipe, 4, 4, 4, 

 to the generator, thus performing a complete circuit. 



The forcing-pump acts with a presure exceeding 35 at- 

 mospheres; consequently, when the water received in it 

 from the condenser is urged itito the generator, itmust ex- 

 pel a portion equal to itself in volume: this portion, as 

 above described, flashes instantly into highly elastic steam. 

 The forcing-pump, too, is so contrived as to act with a 

 a steady force, and, consequently, the expelled water must 

 he driven from the generator in a steady current, and thas 



* The parallel motion represented at PQ, is not the correct one used by 

 >Ir. Perkins. The piston-rod is connected by a flexible joint, with a sort of 

 carriage with four wheels at each end, and working ia a strong horizoBtal 

 box of steel. 



Vol VII.— No. 1. 1.5 



