Pierre Louis Frederic Sauvage, French inventor, 1853.

FRANCE - SEPTEMBER 09: Lithograph after an original drawing by Gavarni of Pierre Louis Frederic Sauvage (1786-1857), French boat builder and inventor of the spinning propeller. Sauvage discovered that sculling an oar off the stern of a boat made it move more quickly, and this led to his invention of the propeller. In 1832, he fitted a propeller to a small model boat and took it to trials, where it outperformed paddle wheel models. Word of his invention reached Paris and he was commissioned by Admiral de Rigny to build a 15 ft (4.6 m) model. The model again tested well, but he never received a contract from the French navy. Instead, in 1840, Sir Francis Petit Smith�s (1808-1874) screw- propelled steamer the �Archimedes� was to prove the success of the propeller, with Smith taking all of the credit for its invention. (Photo by SSPL/Getty Images)