By Dima BusbyBy Dima Busby

Lewis Nixon was born on Aripl 7 1861. He died on September 23 1940.His nick name is Black beard Lew Nix.

The sonar means sound navigation and ranging

The sonar was invented in 1906. Sonar may be divided into three categories:

active, passive, and acoustic communication systems. In active sonar systems, an acoustic projector generates a sound wave that spreads outward and is reflected back by a target object. The projector may be on a floating sonobuoy, attached to a vessel's hull, or suspended in the sea by a line lowered from a helicopter. A receiver picks up and analyzes the reflected signal

The Military uses it to see what there is under the water and hearing what’s under the water.

It is also used today.

Bellis, Mary. "The History of Sonar." Inventors. THe New York TImes COmpany, 2011. Web. 15 Dec. 2011. <http://inventors.about.com/od/sstartinventions/a/sonar_history.htm>.

Wikipedia, the Free Encyclopedia. "Lewis Nixon (U.S. Army Officer)." Wikipedia, the Free Encyclopedia. Wkimedia, 5 Dec. 2011. Web. 15 Dec. 2011. <http://en.wikipedia.org/wiki/Lewis_Nixon_(U.S._Army_officer)>.