BELLOWS

a machine for Mowing fire, so formed as, by being dilated and contracted, to inhale air by a lateral orifice, which is opened and dosed by a valve, and to propel it through a tube npon the fire. As soon as men began to make use of fire the importanoe of bellows was felt, since the natural bellows, if we may give this name to the Inngs, could not be Implied to any great extent. The invention of bellows is ascribed to An achars is the Scythian, though probably it took place in different countries. The f onns cd bellows at present are very various, as many attempts have been made for the improvement of this h^hly important machine, which becomes nece ary wherever a powerful flame is required in the arts. As mining is carried on extensively in Ger^ many, and great heat is required in smelting the ores and working the metals, many new kinds of bellows have been invented in that country, one of which consists of an empty box, which moves up and down in another, partially filled with water. Between the bottom of the empty box and surface of the water is a space filled with air, which is driven out by the descent of the inclosed box. Bellows of very great power are generally called Uowing-mackinea (which see). One of the largest is the one in the smithy of the Boyal Dockyard at Woolwich. It is adequate to the supply of air for forty forge-fires, amongst which are several for the forging of anchors, iron knees, and many other heavy pieces of smithery. The common Chinese bellows consist of a box of wood about 2 feet long and 1 foot square, in which a thick, square piece of board, which exactly fits the intemiJ cavity of the box, is pushed backwards and forwards. In Hhe bottom of the box, at each end, there is a small conical or plug valve to admit the air, and valves above to discharge it.