Cooper^s Rotative Piston. 317 



sion of the other power, while changing the brakes. The 

 engines in New-York are all of this construction, and are so 

 made as to allow the brakes to run the whole length of the 

 engine on each side. The leverage is generally twenty four 

 inches, and the number of men required to work them about 

 twenty. The engines, manufactured in Philadelphia and 

 Boston, likewise work with pistons, but the levers are differ- 

 ently constructed, there being generally one long lever run- 

 ning the whole length, having its fulcrum in the centre, while 

 the brakes are placed at each end. Some of the Philadel- 

 phia engines are of great power, allowing from thirty to for- 

 ty men to work at once, and have from two to four feet lev- 

 ers. Another mode of making engines has been tried with 

 success, which is to place a small cylinder within a large hol- 

 low one, and attach a wing or arm to the small cylinder, and 

 make it sufficiently long to fill the space between the two : 

 a stop is then placed on the opposite side of the small cylin- 

 der, fitted at the end next to the inner cylinder, so as to allow 

 it to play on that end, while the other is attached firmly to 

 the outer cylinder. Heads are put upon the outer cyhnder, 

 secured to it by flanches, and the gudgeons of the inner cyl- 

 inder are secured by stuffing boxes ; levers are put in the 

 ends of the gudgeons of the inner cylinder, to which the 

 brakes are attached. Two sets of valves are made use of, 

 one between the outer cylinder and pipe, the other between 

 the cylinder and air chamber. An engine of this kind is now 

 used by the Sun Fire Insurance Company of London, and 

 one of nearly the same construction, by the name of the Cat- 

 aract, has been in Boston for several years, and is still in use. 

 In many of our cities the organization of the fire depart- 

 ments is excellent ; and particularly in New- York, Philadel- 

 phia and Boston, the vigilance and success of the firemen 

 have inspired a confidence which does honor to them, and to 

 the cities to which they belong. The engines, in these pla- 

 ces, are always found in excellent order, and at first sight, it 

 would seem that human skill and ingenuity had been exhaust- 

 ed in rendering them perfect; but, upon investigation, many 

 defects will appear, which should be remedied as fiir as prac- 

 ticable. The first of these defects is the expense necessary, 

 not only to construct, but to work them and keep them in 

 repair. The best New-York engines cost from seven to eight 

 hundred dollars, including suction hose, and throw through 

 their pipes (3-4 inch) from eighty to one hundred gallons per 



