Tractors Author:John Carroll, Garry Stuart In little more than a century, tractors have gone from being primitive and unreliable to utterly sophisticated and precise machines. With the invention of the internal combustion engine, modern tractors really began pulling their weight on the farm. Tractors is a comprehensive look at the history of these great machines, right up to today's mo... more »st sophisticated models on the market. All major manufactures like John Deere, Massey Ferguson, and Allis-Chalmers are covered.« less