Earning a living as a mariner and fishermen, Patch observed the efficiency of small boats propelled by single oar
sculling and began to experiment with a propeller based in the motions of a sculling oar. During the winter of 1832-1833 he built a hand-cranked version of a doubled-bladed fan-shaped propeller. He demonstrated his propeller during the summer of 1833 before crowds watching as his small boat moved, seemingly magically, across Yarmouth Harbour. Patch further experimented by attaching his invention to a 25-ton coastal schooner named
Royal George in the Bay of Fundy. The propeller allowed
Royal George to enter
Saint John Harbour in a calm which stranded other sailing vessels. Patch's invention was 4 years before
John Ericsson's famous
patent on the screw propeller in Britain. Patch lacked the funds to travel to Britain for a patent but instead tried to patent his propeller in the United States in 1832. However his application was refused as he was not an American citizen. Patch continued to improve his propeller and when American laws changed to permit patents by non-citizens, he received an American patent in 1849. Patch's propeller received some recognition, including praise for its efficiency in
Scientific American magazine. However, by 1849 there were multiple competing versions of the screw propeller in Europe and America. Patch never received money or recognition. ==Later life and death==