Leon Theremin was born in St. Petersburg in 1895. An inventor, he created the theremin while trying to fix local oscillations in a radio–around 1918! The theremin is the first electronic music instrument, regarded as the ancestor of the keyboard synthesizer. The theremin is unique because it is not touched–the musician waves hands near a pair of antennas to alter pitch and volume.
View the original patent on Google, or browse a machine-readable version.
To learn more about MouSing, a sound-creation program for Windows inspired by the theremin, click here: 
For more theremin info:
Theremin: An Electronic Odyssey is a must-see movie, information at http://www.imdb.com/title/tt0108323/
The Theremin Enthusiasts Club International is at http://theremin.ca/
Cult of the Theremin at http://www.zzounds.com/edu–thecultofthetheremin
Subscribe to the Internet news group alt.music.makers.theremin .