Bourdon Tube Air-powered Toys
[Sourced from: Mechanical Toys: How Old Toys Work, by Athelstan and Kathleen Spilhaus (New York: Crown Publishers Inc., 1989)] The principle of the Bourdon tube, a flattened, flexible tube that straightens out under pressure, was used in pneumatic toys such as the rubber monkey that plays a drum when a rubber bulb is squeezed by …