Lanz 'Bulldog' tractor, c 1930.
© Science Museum / Science & Society Picture Library
Agricultural tractor on steel wheels manufactured by Heinrich Lanz, Mannheim AG, Germany. Faced with a fuel shortage in post First World War Germany, in 1920 Dr Fritz Huber of the Lanz company came up with a simple tractor with a multi-fuel engine based on the Englishman Herbert Ackroyd Stuart's invention. It would run on most liquid fuels including crude oil, tar oil, spirit or vegetable oil. The tractor was mechanically simple to allow farmers to repair it with ease, and various versions were made including a stand-alone engine unit for stationary use. The Bulldog illustrated is a more sophisticated later version from the 1930s. It has a 24 hp single-cylinder horizontal two-stroke semi-diesel engine with hot bulb ignition.