APPARATUS FOR EXTINGUISHING FIRES. 495 



ous engines have piston pnnips ; the Silsby engines have rotary 

 pumps, and the La France Engine Company manufactures two 

 distinct styles of engines one with a piston pump and one with 

 a rotary. The piston pump needs no description here, but it will 

 be well to say a few words in regard to the rotary pump. The 

 engine in this case is composed of two cams, which to the uniniti- 

 ated are irregular cog-wheels with alternating large and small 

 cogs, working in a steam-tight case. The steam entering from 

 one direction forces these cams to revolve with great rapidity. 

 The pump is composed of cams somewhat similar, which are con- 

 nected with the engine cams, and when revolving suck the water 

 and force it through the discharge pipe with great pressure. The 

 capacities of steam fire engines differ from three hundred gallons 

 per minute in the smallest sizes up to twelve and thirteen hun- 

 dred gallons per minute in the largest. 



Self-propellers are very little used at the present day. Boston, 

 Providence, Hartford, New York, Brooklyn, Detroit, Chicago, 

 Milwaukee, and other cities, have all tried them, but they have 

 been very generally discarded for engines drawn by horses. Hart- 

 ford is a notable exception to the list, there being two self-propel- 

 lers in her department. The latest of these is an Amoskeag engine 

 by the name of Jumbo, and has a capacity of thirteen hundred 

 and fifty gallons per minute. This is probably the largest land 

 fire engine in the world. The city departments are always fur- 

 nished with the larger sizes of engines drawn by horses, but in 

 many towns engines of lighter draft, that can be drawn by men, 

 are often used. Crane-neck and straight frames are both used, 

 but the former are more common. The American Fire Engine 

 Company make a combination engine and hose wagon called the 

 Columbian engine. The wagon part is forward, and the engine 

 and boiler are over the rear wheels. This is very convenient in 

 suburban departments, as it reduces the number of pieces of appa- 

 ratus. The fire-engine makers of the United States supply the 

 home market exclusively, and a number of machines have been 

 sent to Canada and to foreign countries. 



The most powerful allies of the land engines are fire boats, that 

 are now used by all large cities bordering on the water. The 

 capacity of a fire boat is often equal to that of ten to twenty 

 land engines, and is limited only by the size of a boat that can be 

 worked quickly and easily among the crowded shipping of a har- 

 bor. As has been seen, New York had a floating hand fire engine 

 in use during the early part of this century, but it was not in serv- 

 ice for any length of time. After steam vessels came into gen- 

 eral use, harbor tugs were often provided with fire pumps, that 

 they might aid in extinguishing fires on the water fronts. The 

 first boat built expressly for fighting fire was launched in 1872, 



