LIFE-BUOYS consist of two hollow copper cylinders, each as large as a pillow, and sufficient to support one man stand ing on them : they are connected to each other. Should more than one person re quire support, they can lay hold of rope beckets fitted to the buoy, and so sustain themselves. Between the two copper vessels, there stands a hollow pole, or mast, into which is inserted, from below, an iron rod, whose lower extremity is loaded with lead, in such a manner that, when the buoy is let go, the iron slips down to a certain extent, lengthens the lever, and enables the lead at the end to act as ballast. By this means the mast is kept upright, and the buoy prevented from upsetting. The weight at the end of the rod is arranged so as to afford se cure footing for two persons, should that number reach it ; and there are, also, large rope beckets through which they can thrust their heads and shoulders, till assistance is rendered. At the top of the mast is fixed a port-fire calculated to burn about twenty minutes or half an hour ; this is ignited most ingeniously by the same process which lets the buoy fall into the water ; so that a man falling over board at night is directed to the buoy by the blaze on the top of the mast. The
person who has charge on board ship of the life-buoy sees it freshly primed every evening. In the morning the priming is taken out and the lock uncorked. LIFE-PRESERVERS. Apparatus used at sea in case of persons falling over board. Mr. Scheffer, of England, in vented a cylindrical tubular ring without seam or break ; it contains a stop cock and ivory pipe affixed ; by this air can be blown in by the mouth and retained by the stop cook. When not inflated it folds up into a very small compass, suita ble for the pocket, and weighs only twelve ounces.
An American invention of a similar character in the form of a straight cylin der of a caoutehouc water-proof material. £he simplest form is a ring of caoutchouc to go round the body under the arm-pits, previously blown up with air.