The bel and Mr. Bell

Photo of Decible Meter courtesy of  FreeImagesLive.co.uk

The decibel (symbol dB, one-tenth of a bel) is a unit used in electrical engineering and acoustics to express relative loudness.  What I didn't know is that the bel was named after Alexander Graham Bell(1847-1922).

For more information, in addition to the links above see the website of The Alexander Graham Bell Family Papers at the Library of Congress.

Steam Powered Church Organ

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Pope Sylvester II (946-1003), also known as Gerbert, built church organs powered by steam, a great innovation of the time, which eliminated having people force air through the organ pipes by physically operating bellows while another person actually played the organ keys.

He also constructed the precursor to Galileo's telescope, and became one of the first great collectors of books.

For more information, see the websites of Christian Classics Ethereal Library, and Encyclopedia Britannica.

Rattlesnakes & Ambulance Sirens

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The frequency of the rattle-sound produced by the rattlesnake can reach 5000 hertz to 8000 hertz, which is the same as that of the ambulance siren.

For more information on rattlesnakes, see the websites of the American International Rattlesnake Museum, Kidzone, and Reptile Knowledge.