LIFE-PRESERVEM, inventions for the preservation of life in cases of fire or ship wreck. The fire life-preservers will be found treated of under FinE-EscArEs. The other class includes the various contrivances for preserving the buoyancy of the hutnan body, and for reaching the shore. Of these, the readiest and most effective are empty water-casks, well bunged-up, and with ropes attached to them to hold on by. It has been found that a 36-gal. cask so prepared can support 10 men conveniently, in tolera bly smooth water. Cook's and Rodger's patent life-rafts consist of square frames buoyed up by a cask at each corner. Among foreign nations, frames of bamboo, and inflated goat and seal skins, have been long employed as life-preservers; and in China, it is customary for those living on the banks of the canals to tie gourds to their children, to buoy them up iu case of their falling into the water. Since the introduction of cork, jackets and belts of that material in immense variety have been patented. It has been calculated that one pound of cork is amply sufficient to support a man of ordinary size and make. A few years ago, on the invention of india-rubber cloth, inflated belts of this material were made, and found to be superior in buoyancy to the cork belt, besides, when emptied of air, being very portable. They are, however, much
more liable to damage by being punctured or torn, or to decay by being put away while damp. Soine of these defects are reznedied by having the interior of the belt divided into several compartments; so that, when one is damaged, the remainder may still suf fice. Various forms of inflated mattresses, pillows, etc., have been made on the satne principle, and been found very effective; one shown at the great exhibition of 1831 hav ing sustained 96 lbs. for five days without injury. But the favorite life-buoy among •.ailors is composed of slices of cork neatly and compactly arranged, so as to form a buoyant zone of about 30 or 32 in. in diameter, 6 in width, and 4 in thickness. It con sequently contains about 12 lbs. of cork, and is generally covered with painted canvas to add to its strength and protect it from the injurious action of the water. A buoy so constructed can sustain persons, and it is generally furnished with a (a cord running round the outside of the buoy and fastened to it tit 4 points) to afford a more convenient hold. This life-preserver is found on board all vessels. See LIFE MORTARS AND ROCKETS.