ROCKET is a firearm capable of taking effect at a long range. The rocket consists of a light tabular ease of pasteboard, or thin metal, charged to the muzzle with acompo sition consisting of saltpeter 68 parts, sulphbr 12 parts, charcoal or inealed powder 32 parts. This composition is rammed hard into the case, the center being left void. To the rocket is attached a long stick, which serves (like the tail of a kite) to straighten its course. See PYROTECHNY. When lighted at the end the stream of gases propels the mass on the principle explained under BARKER'S MILL As a mere firework, rockets are made of a few ounces in weight: as intended to throw light upon a,town or a hostile work, they average from lb. to 2 lb. These light rockets were improved by sir Williani Cougreve, who so contrived them, that, when over the necessary point the rocket discharged a number of light balls, which burned in the air for several Tintites with great brilliancy, while others at the same point released small parachutes, which sustained a bright light for a still longer time. But sir William Congreve did more: he converted the rocket into a terrible weapon of war, with ranges which no ordnance of that day could attain. Discarding the small sizes, he made 12-lb., 18-lb., and 32-lb.
rockets, which lie charged with canister-shot, bullets, and other missiles. The stick for a 32-lb. rocket is 18 ft. in length, and the maximum range 3,500 yards. The range can be also increased by discharging the rocket from a cannon, with a time-fuse to ignite it at the cannon's utmost range, when the rocket commences its own course. As missiles, these rockets are found to annoy most seriously the defenders in any fortified work, and, in a bombardment, they speedily set houses and buildings on fire. In the field, also, the plunging, ricochetting motion of the rocket greatly disturbs both cavalry and infantry. The Congreve rockets were first tried on actual service, and with fatal effect, at the attack on Copenhagen in 1807. One great advantage in a rocket is, that it has no recoil against the stand from which it is fired; the largest rocket may therefore be dis charged without danger from the smallest boat; consequently, iu naval attacks on mari time fortresses, a flotilla of rocket-boats is a very common auxiliary. For the use of rockets in shipwrecks, see LIFE MORTARS AND ROCKETS.