AND SURFACE CONDENSER. 347 



against the outside of the air-vessel, and opposite to the two 

 outlet valves of the blowing cylinder two apertures are made in 

 the air-vessel, through which the air is forced in. The main 

 cylinder of the engine, of the usual dimensions according to 

 power wanted, is also screwed against the outside of the air- 

 vessel high enough above the blowing cylinder to allow room 

 for the main-crank shaft to work between them. The forcing 

 pump before mentioned is also screwed to the outside of the 

 air-vessel, and thus my improved steam-engine becomes more 

 compact and convenient than any preceding steam-engine. 

 For the purpose of supplying the boiler with distilled water, in 

 case there should be a deficiency in it, a small vessel made of 

 two upright tubes, one within the other, is placed on the cap- 

 piece. The inner tube is of the same diameter as the flue, and 

 forms a continuation of it. The outer tube is about 6 inches 

 larger than the inner, and the space at the top and bottom 

 between the two tubes is closed by two ring-shaped pieces. 

 This vessel may be about 18 inches high ; a cock is fixed in the 

 top of this vessel, to which a bent pipe is fastened, leading to 

 and united with a pipe which arises from the top of the con- 

 denser and passes through a hole in the cap-piece, and thus a 

 communication between the supplying vessel and the condenser 

 may be opened or shut at pleasure ; another pipe, also furnished 

 with a stop-cock, arises from the vessel, and communicates with 

 a water-cistern to receive its supply of water when required ; a 

 third pipe, having a cock in it, opens into the vessel near the 

 bottom to let out the sediment ; a small cock to let the air out 

 is also fixed in the top of the vessel, which cock may also be 

 used for letting air out of the condenser. In order to supply 

 the boiler with water by means of this vessel, the stop-cock 

 leading to the condenser is shut, and that leading to the cistern 

 is opened, and at the same time the air-cock is opened to allow 

 the air to escape that the water may fill the vessel. When the 

 vessel is nearly full of water, the air-cock and the ccck from the 

 cistern are shut, and that in the pipe leading to the condenser 

 is opened. The water being then heated by the flue is con- 

 verted into steam, which, passing into the condenser, is there 

 reduced to water again, leaving the sediment or salt in the 



