Andy Brown, age 12, of Helena, Mont., for his question:

WHO INVENTED THE CONCERTINA?

The concertina is a musical instrument in which metal reeds are made to vibrate by air pressure produced by means of a bellows. The popular European instrument was invented in 1829 by a British physicist and inventor named Sir Charles Wheatstone.

Small keys or plugs in the end plates of the concertina are pressed by the player. These keys open valves that control the reeds. The treble concertina uses the most valves in a small, six sided instrument with a range of about three and a half octaves.

There are also tenor, bass and contrabass concertinas. The instruments sound somewhat like accordions.

Sir Weatstone also experimented on the speed of electricity in wires and suggested that electricity be used to send messages. With a man named W.F. Cooke, he patented an electric telegraph in 1837, about the same time that Samuel Morse developed his telegraph.