What does "bellows" mean?

Bellows: An instrument, utensil, or machine, which, by alternate expansion and contraction, or by rise and fall of the top, draws in air through a valve and expels it through a tube for various purposes, as blowing fires, ventilating mines, or filling the pipes of an organ with wind. Bellows camera, in photography, a form of camera, which can be drawn out like an accordion or bellows. -- Hydrostatic bellows. See Hydrostatic. -- A pair of bellows, the ordinary household instrument for blowing fires, consisting of two nearly heart-shaped boards with handles, connected by leather, and having a valve and tube.