In 1884, he went to Canada to work for a firm of electric vehicle manufacturers. In 1894, he returned to England, where he invented a double-acting diesel-steam engine in which waste heat from the cylinder jacket and the exhaust was used to produce steam to assist the diesel engine. This is covered by United States. patent 1230617 of 1917.
Still also invented the Still heat-transmitting tube which was used in refrigeration plant.
Was used experimentally for stationary, marine and locomotive applications. The best-known application was the Kitson-Still locomotive of 1926 which was tried out on the London and North Eastern Railway
gave an increase in thermal efficiency over an ordinary diesel engine but was not a long-term success because of the added complexity of the steam system.
Still obtained a large number of British, Canadian and United States. patents. Some examples follow:
GB191317862, Improvements in means for injecting fuel into the cylinders of internal-combustion engines
CA49886, Rectifier for electrical currents
US547043, Rectifier for electrical currents
US1171899, Manufacture of gilled tubular apparatus
Although the titles of Canadian patents are available from 1869, the full details of pre-1978 patents have not yet (December 2014) been put on-line.