A machine used to agitate the air, and cause it to impinge upon other bodies to reduce their temperature. Those used for cooling the person are made of every variety of form and materials that fancy can invent; but they generally consist of a piece of paper, satin, or any other light fabric, cut semicircularly, and mounted upon several little sticks of wood, ivory, tortoise-shell, or the like. If the stuff be single, the sticks of the mounting are placed on the least ornamented side; if double, they are placed betwixt them. The paper is plaited in such a manner that the sticks may be alternately inward and outward. In the middle of each plait the sticks are cemented; all of which are cut exceedingly thin and delicate, and they are connected together at the end by a single rivet, by which the fan, as it is held in the hand, may be either folded up or expanded. The Chinese and East Indians excel in elaborate carving upon the fan sticks; but the elegance and taste displayed by our own artists upon the other parts, are unrivalled.
The term fan is applied to those small vanes or sails that receive the impulse of the wind, and, by a connexion with machinery, keep the large sails of a smock windmill always in the direction of the wind; see Windmill.
Also a rotative blowing machine, consisting of vanes turning upon an axis, used for winnowing corn. Similar apparatus is used to decrease the speed of light machinery, by the resistance of the air against the motion of the vanes.