Abe Lincoln's patent for a river navigation device http://feedproxy.google.com/~r/cnet/tcoc/~3/lanJsaVIkSk/

Abe Lincoln's patent for a river navigation device Looking back: On March 10, 1849, the future president filed a patent application for his imaginative method of "Buoying Vessels Over Shoals." [Read more]

via Nerds never Sleep http://feedproxy.google.com/~r/cnet/tcoc/~3/lanJsaVIkSk/