Who invented the tractor

in p>177, edgeworth invented a kind of "railway or artificial road that can drive any carriage and move with it", and obtained a patent in Britain. His method is to connect several wooden slats into an annular chain and move continuously in a certain way so that one or several slats always contact the ground. His purpose is to spread the weight of the carriage to a wider ground when using narrow wheels, so that the carriage can travel on rugged or soft ground. However, edgeworth's designs all stay on drawing paper. Bater, an American inventor, obtained a patent for crawler in 1888. In 194, Holt also obtained a patent for the invention of a very practical crawler, and put it into mass production in 196, replacing the rear wheel of the original steam tractor with a crawler, and Holden crawler tractor appeared. This is the kind of tractor that was first converted into a tank. In 194, Hornsby and Sans Company in Britain had successfully carried out trial production according to a much more complicated design of david roberts. It is characterized by connecting all separated links with lubricating bolts. In 197, the first gasoline-driven crawler tractor ran on this track and gave a performance to the War Department. However, due to that decline of military enthusiasm, Hornsby sold their patent to Holt in 1912.