MECHANICS AND USEFUL ARTS. 47 



combustion chamber there are apertures which are opened or closed at 

 pleasure, and by which air can be let in to burn the gases not yet consumed. 

 The consumption of coal on the first trip, between New York and Pough- 

 keepsie, was 4,200 pounds instead of the usual four cords of wood ; that is to 

 say, thirteen dollars and twenty-five cents instead of twenty-eight dollars- 

 Pimpfel's tubular boiler is intended for any kind of fuel, and, it is alleged, 

 answers perfectly for coal-burning locomotives. A large machine of this 

 style was built by the Taunton Locomotive Manufacturing Company, and is 

 now drawing express trains over the Ei'ie Railroad, using anthracite alone. 

 The fire-box and the barrel form one chamber, through the whole length of 

 which the smoke passes, escaping into the smoke-box through an opening in 

 the lowest part of the barrel near the smoke-box. The tubes extend out of 

 the barrel over the fire ; there they bend upward, and the top of the furnace 

 becomes a tube sheet. With this arrangement the water is inside the tubes 

 and the fire outside between them, in the manner adopted for the boilers of 

 the Collins steamships. The inventor claims to have by this arrangement 

 entirely done away with the burning of the end of the tubes and of the top 

 of the fire-box, which is the ordinary consequence of a coal fire in a locomo- 

 tive built on the usual plan. 



IMPROVEMENTS IN LOCOMOTIVES AND RAILROAD CARS. 



Preslage's Improved Locomotive. This invention is attracting considerable 

 attention in England, and is similar to the one used on the steamer Arctic at 

 the time of her loss. It aims at fulfilling the conditions suggested by the 

 Franklin Institute as behig necessary for the economical working of super- 

 heated steam, the committee reporting that there would be great economy 

 in using superheated steam or stame, if it could be brought into operation 

 where the temperature of colder bodies would not interfere to abstract the 

 heat before it could be profitably employed. The cylinders and working 

 parts of the machine are placed above the boiler, instead of underneath, as is 

 usual, and the boiler is in consequence lowered, thus giving more stability to 

 the engine and bringing its centre of gravity more directly to the line of at- 

 traction. The removal of mechanism from under the boiler leaves a space 

 available for the construction of a tank, which surrounds it in such a manner 

 as to maintain against the boiler a sheet of feed water, which is there heated 

 by the radiating heat preparatory to its being fed in. The cylinders are en- 

 circled by jackets, and arc placed in the smoke-box. The steam in its pas- 

 sage from the boiler to the cylinders, is led into these jackets, where it is 

 superheated. It is expected that the consumption of the fuel will be dimin- 

 ished one half by the use of this invention. This expectation is by no means 

 unreasonable, when we remember that a locomotive uses about three times 

 more fuel per horse power than the most expensive stationary engine. 

 Besides, the use of stame in lieu of steam does not require so large a boiler, 

 and the room thus gained allows an increase of the furnace sufficient for the 

 use of coal, Avhich is a cheaper combustible than wood or coke. 



New Form of Locomotive. A new form of railroad locomotive has re- 



