Complete Encyclopaedia of Music/B/Bellows of an organ

Bellows of an organ. The bellows are the pneumatic part of the machine, by which it is supplied with wind, and is wrought by a man called the blower ; but in small organs by the foot of the player. This machine is of various constructions, but in general is composed of two flat boards, sometimes of an oval, sometimes of a triangular form ; two or more hoops are placed between them, and bent according to the figure of the boards ; a piece of leather, broad in the middle and narrow at both ends, is nailed on the edges of the boards, that the leather may the more easily open and fold again ; and there is a valve within, that covers the holes in the under board, to keep in the air.