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bags should be small and numerous, to multiplythe chances against injury by shot holes; for asingle musket ball, penetrating a bag, instantlydeprives it of all it’s principle of buoyancy.This is a danger to which rafts, formed of in-flated skins, were not exposed, in the time of theancients; hut is now an insuperable objectionto their general application.

Wherever troops are regularly supplied withfresh meat, or cattle abound, a sufficient numberof animal skins may soon be collected to form,in this way, a considerable raft. The followingexperiment was made with an ox hide, trimmedinto circular shape, of about 5 feet 6 inches indiameter. The skin was drawn together at theedge, and firmly bound round a tube made of aldertree, having the pith removed, and a piece ofleather nailed upon the inner end, as a valve toprevent the air from escaping. The vessel wasinflated by a common hand-bellows, and floated.‘500lbs.; and, without any application to closethe pores of the skin, remained nearly fully in-flated for five hours, and at the end of twenty-four hours was still found capable of floating150lbs. The weight of the skin was 45lbs., sothat by this expedient, great power of floata-tion may be packed in small space, and easilytransported. Skins may be preserved for a