268 



HEAT. 



The condenser, J, shown directly under tlie cylinder, re- 

 mains to he described. It is immersed in a cistern of cold 

 Avater, and is connected by pipes with the upper and lower 

 end of the cylinder. Through these pipes the steam 



Fijj. 291. 



Low-pressure Steam-engine. 



passes out of the cylinder, first from one end and then 

 from the other, and is condensed into Avater by a jet of 

 cold water thrown into it by the hijection-cocTc, When 

 condensed, it is pumped out by the pump, 0, into the well 

 or reservoir, TFJ and then again into the feed-pipe of the 

 boiler. Warm water is thus constantly supplied to the 

 boiler, and effects a great saving of fuel. 



The supply of steam and the motion of the engine are 

 regulated by the governor^ G. When tlie motion is too 

 fast, the two suspended balls, which revolve on a vertical 

 or upriglit axis, and which hang loosely like pendulums, 

 are thrown out from the axis, producing the movement of 

 a rod which shuts the steam-valve. When the motion 



