SELF-ACTING FEEDEE. 



Fig. 4. 



In the most effectual of these methods, the task of replenishing 

 the boiler must still be executed by the engineer ; and the utmost 

 that the boiler itself was made to do, was to give due notice of 

 the necessity for the supply of water. The consequence was, 

 among other inconveniences, that the level of the water was 

 subject to constant variation. 



10. To remedy this a method has been invented, by which the 

 engine is made to feed its own boiler. The pipe G (fig. 4), which 

 leads from the hot water pump, terminates in a small cistern c in 

 which the water is received. In the bottom of this cistern, a 

 valve v is placed, which opens upwards and communicates with a 

 feed pipe, which descends into 

 the boiler below the level of the 

 water in it. The stem of the 

 valve v is connected with a lever 

 turning on the centre D, and 

 loaded with a weight F dipped 

 in the water in the boiler in a 

 manner similar to that described 

 in fig. 2, and balanced by a 

 counterpoise A in exactly the 

 same way. When the level of 

 the water in the boiler falls, 

 the float F falls with it, and 

 pulling down the arm of the 

 lever raises the valve v, and 

 lets the water descend into the 

 boiler from the cistern c. When 



the boiler has thus been replenished, and the level raised to its 

 former place, F will again be raised, and the valve v closed by 

 the weight A. In practice, however, the valve v adjusts itself by 

 means of the effect of the water on the weight F, so as to permit 

 the water from the feeding cistern c to flow in a continued stream, 

 just sufficient in quantity to supply the consumption from evapo- 

 ration, and to maintain the level of the water in thejboiler 

 constantly the same. 



By this arrangement the boiler is made to replenish itself ; or, 

 more properly speaking, it is made to receive such a supply, as 

 that it never wants replenishing an effect which no effort of 

 attention on the part of an engineman could produce. But 

 this is not the only good effect produced by this contrivance. 

 A part of the steam which originally left the boiler, having 

 discharged its duty in moving the engine, is lodged in the hot 

 well c (fig. 4), and is again restored to the source from which it 

 came, bringing back to the boiler all the unconsumed portion 



7 



