Description of Mr. Perkins’ New Steamekngine, 115 
water now escapes through a valve opening outwards, along 
4, 4, 4; thus effectually cutting off all direct or uninterrupt- 
ed.communication between the generator and the condens- 
er. In order to keep the water in the condenser at a press- 
ure of 5 atmospheres, the blast of the bellows H goes round 
the condenser STXYV ; but when it is not sufficient for this 
engine, notwithstanding its tremendous energies, much 
more safe in its operations than even the common low pres 
ure engine. 
ae tube 8, 8, 8, communicates also with the indi- 
cator ¢ d, having a dial-plate ¢ e, and an index ¢ J, which, 
by means of a suitable contrivance at v, 2, indicate the 
Pressure or number of atmospheres with which the engine 
18 working, 
The cylinder and piston PPQ, have been separated from | 
et the engine, for the sake of distinctness. Their 
proper sige however, wil] be understood by supposing 
the two lines 9, 9 ; 9, 9 to coincide. 
