HOW IT WORKS.

reed, such as is found in the ordinary motor horn. The elastic metal tongue when at rest stands a very short distance away from the orifice in the reed. When wind is blown through the reed the tongue is sucked against the reed, blocks the current, and springs away again. A free reed has a tongue which vibrates in a slot without actually touching the sides. Harmonium and concertina reeds are of this type. In