MECHANICS AND USEFUL ARTS. 23 



the principle of it consists in bringing a receiver alternately in com- 

 munion with the water-tanks, and then with the steam and water of 

 the boiler, so as to receive the water in the one case, and pass it into 

 the boiler by the steam at the water-line in the other case. To effect 

 this there is a small revolving disk driven by a pinion, which works 

 steam-tight between two metal plates, communicating with the boiler 

 by a tube passing down into the water in it. Above it communicates 

 with the water-tank by a pipe and also with the steam. The revolv- 

 ing disk has a receiver in it, which takes the water from the tank 

 above, carries it round between the upper and lower plates until it is 

 passing above the feed-pipe into the boiler below, when it is at once 

 brought into connection with the steam-pipe above, and the water is 

 deposited in the boiler. It will be observed that if the water is up to 

 the line of the revolving disk, the water in the receiver will not be 

 pressed into it, but will be carried round. It can be operated by a re- 

 ciprocating motion, and its principle is like that of the slide-valve. It 

 is the invention of Mr. Foskit, of Meriden, Connecticut. 



STEAM GENERATOR. 



The London Times contains an account of a new invention called 

 " Wright's Patent Steam Generator," some experiments with which 

 have been entirely successful. The principle of the invention consists 

 in applying to the boilers of steam-engines an arrangement of what 

 are called "cellular vessels," formed of malleable cast-iron, one ves- 

 sel being placed underneath the boiler and over the fire, while the oth- 

 er is placed within the boiler. They are connected by means of bent 

 tubes, so as to have a free communication with each other, but are 

 insulated as regards the water in the boiler. They are charged with 

 water, \vhich, except from any slight unavoidable waste, is never 

 changed, and there is a small safety-valve connected with them, which 



/ 



is so loaded that the temperature of the insulated water contained in 

 the cellular vessels may, if necessary, be raised to 400 degrees or 500 

 degrees of Fahrenheit without forming into steam. The vessels, 

 therefore, remain perfectly charged, and the insulated water in the 

 lower vessel taking up the principal portion of the heat of the fire, 

 rises by its inferior gravity through the bent tubes, and is diffused 

 through all parts of the cellular vessel within the boiler. The excess 

 of heat is there instantly given off to the water in the boiler, and the 

 insulated water descends by increased gravity to take up a fresh charge 

 of heat. The result of the experiments made with this ingenious inven- 

 tion was an evaporation at the rate of 12.8 pounds of water to 1 pound 

 of coal, the rate given by the present construction of boilers being stated 

 at 8 pounds of water to 1 pound of coal. Besides the saving of fuel 

 which would thus appear to be effected, there is also the obvious ad- 

 vantage that the flame hardly impinges upon the boiler from the inter- 

 vention of the cellular vessel, and the boiler is thus saved from the 

 rapid deterioration to which it is now exposed by the excessive heat 

 which plays upon it. The principle of the invention is equally appli- 

 cable to every boiling and evaporating process, but if after a more ex- 



