Lanz 'Bulldog' agricultural tractor on steel wheels, by Heinrich Lanz Mannheim AG, Germany, Serial No. 110615, c. 1930. Engine: 24 hp single cylinder horizontal two stroke semi-diesel with hot bulb ignition. 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, vegetable oil, etc. 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 development from the 1930s, but the design evolved until production ceased in 1962. The basic concept was used by makers in other European countries including a version built by Marshall of Gainsborough, Lincolnshire. This latter tractor differed from the original in that it was a full d