1812 - invented a machine to individually number banknotes. 1814 - appointed as full-time artist to the Bank of Ireland. 1817 - took out a patent for a method of propelling ships by means of paddles. 1820 - took out another patent improving his previous invention for a paddle wheel. 1821 - invented the Oldham coupling, a device to aid in paddle placement on paddle-wheels.1827 - took out a patent for a feathering paddle-wheel.