A snowmobile (or snow scooter, often referred to by enthusiasts as a 'sled' and in the Canadian north and Alaska as a 'snowmachine') is a land vehicle propelled by one or two rubber tracks, or belts, with skis for steering. They are designed to be operated on snow and ice, and require no road or trail. Most snowmobiles are typically powered by two-strokegasoline/petrol internal combustion engines. Even though they are not designed for it, snowmobiles will skim on top of water if the speed is high enough, as demonstrated by the annual snowmobile river drag race in Kautokeino, Norway. Summertime occupations for snowmobile enthusiasts can also involve drag racing on grass or even asphalt strips. People that drive them are commonly known as snowmobilers.
History
The earliest snowmobiles were modified Ford Model Ts with the undercarriage replaced with tracks and skis. They were popular for rural mail delivery for a time. This early history can be traced to Carl Eliason [http://www.eliason-snowmobile.com/summary/carlword.htm in Sayner, Wisconsin with his first hand built model completed in 1923. He was granted a U.S. patent in 1927. Polaris Industries in Roseau, Minnesota, in the United States Midwest, was a pioneer in the production of purpose-built snowmobiles.
The relatively dry snow conditions of the United States Midwest made the converted model Ts and other like vehicles not suitable for operation in more humid snow areas such as Southern Quebec. This led Joseph-Armand Bombardier of the small town of Valcourt in Quebec, Canada, to invent a different caterpillar track system suitable for all kinds of snow conditions. Bombardier had already made some "metal" tracked vehicles since 1928, but his new revolutionary track traction system (a toothed wheel covered in rubber, and a rubber and cotton track that wraps around the back wheels) is his first major invention and led him to become an industrialist. He started production of a large, enclosed, seven-passenger snowmobile in 1937, the B-7 and introduced another enclosed twelve-passenger model, the B-12 in 1942. The B-7 had a V-8 flathead engine from Ford Motor Company. The B-12 had a flathead in line six cylinder engine from Chrysler industrial, and 2,817 units were produced until 1951. It was used in a lot of applications, such as ambulances, canada post vehicles, winter "school buses", forestry machines and even army vehicles in world war 2. But Bombardier, all his life, had always dreamed of a smaller version, more like the size of a moto or scooter.