42 ' ANNUAL OF SCIENTIFIC DISCOVERY. 



In this department was exhibited an ingot of platinum, weighing 

 over two tons. 



PAINE'S SPRAY SUPERHEATED STEAM-ENGINE. 



This engine, for which steam is generated on a very ingenious prin- 

 ciple, differs from an ordinary steam-engine in the following essen- 

 tials : For the latter, as everybody knows, a boiler is used containing 

 a considerable quantity of water, to which the heat of the furnace is 

 most directly applied, and from which the steam is generated. Such 

 a boiler is a magazine of force, because it contains a far greater 

 amount of steam and heated water than is required to supply the 

 engine at each stroke. Herein consists the danger from explosions 

 in common boilers. A hot-air engine has no magazine of force like 

 a steam-boiler. Its heater is supplied with the exact amount of air 

 requisite for each stroke, hence its immunity from explosion. This 

 new engine embraces a similar principle. It has a peculiarly con- 

 structed heater, into which the exact quantity of water for each stroke 

 is fed in the form of spray, then it flashes into steam, and passes over 

 an extended heated surface to the working cylinder. 



A single acting engine, working in New York, has the following 

 dimensions : Its steam cylinder is seven inches in diameter ; the 

 stroke of piston, seven inches. It is situated upon a small tank thirty 

 by thirty-four inches, which forms the bedplate and the heater of the 

 feed-water. The feed-pump has a stroke of one-fourth of an inch, 

 and the water is fed through a quarter-inch pipe. The steam-heater, 

 outwardly, resembles a vertical cylindrical stove. It is thirteen inches 

 in diameter, and thirty inches in height. There are nineteen double 

 tubes inside, and the steam passes between these, and is heated on 

 two sides. The circular grate, containing the fire, is capable of being 

 adjusted by a lever, and set at any required distance from the bottom 

 of the heater. The steam exhausts into the tank upon which the 

 engine stands ; the feed-water, nearly at the boiling temperature, is 

 conveyed into the heater in a fine shower through a small conical 

 chamber on the top of the heater. A small quantity of superheated 

 steam is contained in the heater, and the feed-water, in the form of 

 spray, is instantly converted by it into saturated steam. The pipe for 

 supplying the cylinder with steam is situated nearly at the bottom of 

 the heater ;. hence the saturated steam formed from the feed-water at 

 the top of the heater has to pass in a current between the double 

 tubes on its way to the cylinder, and it thus flows over a very ex- 

 tended heating surface and becomes superheated. A constant cur- 

 rent of steam is maintained in this manner over the heated surfaces 

 of the tubes. By such a heater and such arrangements of the parts 

 of the engine, nearly all the heat is economized, and a perfectly safe 

 steam-engine is secured. If the feed-pump were to cease working or 

 the supply of water to become exhausted, the heater would become 

 like an empty oven after a few strokes, and the engine would stop of 

 itself. For pumping water, printing-presses, sawing wood, and various 

 operations requiring a small motor from one to ten horse-power, this 

 engine appears to be well adapted, as it is compact, safe, and easily 

 controlled. Scientific American. 



