Bellows is a device that produces wind by sucking air through one or more valves and then pumping it out. A simple bellows has a single air chamber, formed by two boards and soft leather sides. This bellows expels strong puffs of air through a nozzle. A hand-pumped simple bellows is commonly used to make wood in a fireplace burn intensely. A double bellows has two chambers and produces a continuous flow of air. More complex bellows help produce sound in such musical instruments as accordions and pipe organs.
