Joseph Ludwig Franz Ressel (June 29, 1793 - October 9, 1857) was an Austrian-Czech forester and inventor who designed one of the first working ship's propellers. He worked for the Austrian government as a forester to secure a supply of quality wood for the Navy. He began testing his ship propellers for the first time. He was awarded a propeller patent in 1827. In 1829 he modified a steam-powered boat and test drove it in the Trieste harbor at six knots before the steam conduits exploded. The police banned further testing. The explosion was not caused by the tested propeller as many believed at the time. Among other his inventions are pneumatic post and ball and cylinder bearings. He was granted numerous patents during his life. He died in 1857 at the age of 64. A monument to him in a park in Vienna commemorates him as "the one and only inventor of the screw propeller and steam shipping".