The circulation, as shown by the arrows, is down the "leg" E, and up through the " nests " K, discharging steam and water laterally from the openings over the crown-sheet L. By this means the crown-sheet is always protected by a pan of water formed by the extended edges of the fire-box sheet D. and can not be injured, whether the water-line is carried above or below the sheet, so long as enough water remains in the " leg " E to supply the " nests." The following are the results of a series of official tests (competitive) of a second-class La France engine. made by the Philadelphia Fire Department in April, 1886: Height of engine over all, 9 ft. 6 in.; length over all, 24 ft. 6 in. ; width over all, 6 ft. ; weight without supplies, about 6,700 lbs. Running 11 hours with 50 ft. of hose, 11-in, nozzle, average steam-pressure, 1091 lbs., average water-pressure, 1751 lbs. ; running 30 min. with 400 ft. of hose, 11-in. nozzle, average steam-pressure, 124i lbs., average water-pressure, 260 lbs.; running 25 min. with 400 ft. of hose, 1/-in. nozzle, average steam-pressure, 125 lbs., average water-pressure, 275 lbs. total running time, 2 hours 25 min. Consumption of coal, 1,446 lbs., an average of lbs. per hour.
The following shows the steam-making and water-throwing capacity of an engine of this type, as determined by experiments at Chester, PiL, in 1887: Steam-pressure after 1 min.... 2+ lbs.
if 46 " 4 " 38 it ti al 66 120 Horizontal distance of stream thrown with 11-in, nozzle and 100 ft. of hose on each coup ling, 265 ft.; with nozzle, same amount of hose, 308 ft. ; with 1+-in. nozzle, 312 ft. ; with 11-in, nozzle and two separate streams, through 500 ft. of hose each, 235 ft.
The Button Steam Fire-Engine, represented in Fig. 9, has an upright tubular boiler with copper flues, which are so arranged as to be always covered with water at whatever inclina tion the engine is worked. Plunger pumps are employed, which are cast in a single piece without packed parti tions. All the movable parts of the engine are reciprocating. The manu facturers claim that a double-pinup en gine having pumps 6 in. diameter by 41 in. stroke throws precisely the same quantity at each revolution as an ordi nary double-pump engine with pumps 41 in. diameter by 8-in. stroke. "The travel of the pistons in such an engine is 32 in., while in the Balton it is but 18 in.. and the sq. in. of frictional sur face are 1.218, as against 819 in. to do precisely the same work." These ar rangements, it is claimed, produce a double-plunger engine, which operates with minimum friction, while it dis charges a continuous stream like a fountain or hydrant, and has no dead center or point at which the steam will not start it.
The following shows the results of a recent test of the third-size Balton engine at Akron, Ohio: Weight of machine, 5.800 lbs.; steam-pressure, after 21 min., starting with cold water,
5 lbs.: after 6 min.. 40 lbs. With a steam-pressure of 130 lbs., and a water-pressure of 228 lbs., water was lifted 131 ft. With a nozzle water was thrown horizontally 292 ft.
The Ahrens Steam Fire-Engine, manufactured by the Ahrens Manufacturing Co., of Cin cinnati, Ohio, is illustrated in Fig. 10. The principal feature of this engine is its boiler, which is represented in the sectional views, Figs. 11, 12, 13. This has a steam and water space, which forms the fire-box, and inside of which is fastened a coil, through which the water is forced—a circulating pump being especially provided for this purpose. The water enters the coil at D, and is converted into steam while traversing the pipes IF, and finally the mingled steam and water passes back to the boiler at A. The coil is supported by the slats B. By removing the bolts out of slats BB, breaking joints top and bottom, any or all sections of coil can be removed, should any repairs be necessary, and any or all may be re placed in a few hours. The water, in entering at D, is separated into two parts, and then into four parts, by a patent device inserted in the dividers at the bottom, so that each section gets its equal amount of water in proportion to the number of feet of pipe in the section. At J are the grate-bars, and at IV the water-line. The makers 2laitn that from 31 to 40 gallons of water can be carried without interfering with the generation of steam, that steam can be generated as readily with 38 gallons of water as with 30 gallons, and that in sufficient quantity for the engine to throw water from a nozzle in 4 min. from the time of lighting the fire.
The Amoskeag ,Sleant Fire-Engine has an upright tubular boiler and a donble-neting and vertical piston-pump. The following results of tests of it first-size engine of this type are given by the manufacturers, as determined at Syracuse, N. V., in August, 1885 : Height of engine over all, 9 fl. 1 in.; length over all, 24 ft. 2 in.; width over all, t3 ft.: weight without supplies, taxon 8,000 lbs. ; capacity, 900 gallons per min. Ilorizontal streams were thrown through smooth-bore nozzles as follows: 1+-in. nozzle, 334 ft.; 14-in. nozzle, 334 ft. ; I g-in. nuzzle, 329 ft.; la-in, nozzle. :31.6 ft.; two streams, 14-in. nozzles, 290 ft.
biby Steam Fire-Engine (Fig. 14).—It is claimed for this engine that there is an entire absence of valves, connecting-rods, eccentrics, cross-heads, cranks, balance-wheels, paeking-plates, and other complicated parts, and that the machine stands still while running even at. Its greatest speed. The motion of the pump being equable, continuous. and rotary, no blows are given to the water, which enters and leaves in one steady flow, and there is no irregu lar motion to the stream.