CONDENSEK. 



c c, is filled with cold water. Immersed in it is a metal vessel, 

 B, called the condenser. A pipe, s s, connects this condenser 

 with the exhausting pipe of the cylinder, of which s s may be 



s 



considered as the continuation. A jet-pipe, E, enters the con- 

 denser, and is bent upwards. It is terminated with a piece pierced 

 with holes like the rose of a watering-pot, and the cold water of the 

 cistern, c c, being pressed in through the pipe, E, is thrown up in 

 the condenser, as shown in the figure. The steam, escaping from 

 the cylinder along the pipe, s s, encounters this cold jet and is 

 instantly condensed. Mixing with the cold water of the jet, it 

 forms warm water, which collects in the bottom of the condenser. 



If means were not provided for the removal of this water, the 

 vessel B would soon become choked with it, so as to arrest the 

 action of the apparatus. 



38. But there is also another effect, which it is important to 

 explain. Water as it commonly exists always contains more or 

 less air fixed in or mingled with it. The air thus fixed in the 

 water of the cistern, c c, is disengaged in greater or less quantity 

 by the heat to which it is exposed when the steam is mixed with 

 it in the vessel B. This air, rising through the tube, s s, offers 

 more or less resistance to the escape of the steam, and reacts upon 

 the piston to the detriment of the moving power. Its accumula- 



31 



