The World of tractors

With the use of 350 photos, the author traces the history of the tractor in England and the United States, starting with Jethro Tull's revolutionary mechanical seed drill in 1701, describing the early steam and gas-powered models, and explaining the impact of the Great Depression and two world wars on production of what has become a required piece of farm equipment. People whose efforts speeded up the development of farming machinery are also discussed.