VIII.—PARACHUTES.

This simple contrivance often forms an adjunct to balloons. Its appearance is generally that of a huge family umbrella of revolutionary times. It is likewise concave underneath, because such form, above all others, condenses a column of atmosphere more rapidly and retards its velocity in the descent immensely. The ribs are generally of whale-bone or bamboo covered with strong domestic muslin, and a light wicker basket is fastened some twelve feet underneath for the æronaut, who may cut himself loose from the balloon with perfect safety at any hight, and descend slowly to the ground, if the parachute is strongly made and perhaps fourteen feet across when open.

By giving it a slight inclination, it can be made to descend, sliding-like, a long distance from the vertical point; and some of the flying machines we read of have likely been only a modified form of the parachute. The nautilus on the ocean moves on the principle of it, the pollen of plants is carried from one place to another by this mode; so the flying squirrel moves in parabolic curves from tree to tree and even crosses rivers when the nut crop fails; as also the flying tree-frog slants down long distances from high trees. This animal has a considerable expansion of skin, connecting the toes only, and which looks as if on its four legs were fastened those short, broad and light snow-shoes, known as Webfeet, used in our northern Territories in winter. It is, therefore, called a "webfoot" frog, but from which must not be inferred that it is "an Oregonian," for it is encountered so far only in Borneo.