The "Bear" evolved from a design of heavy tractor that was first developed by Wallis in 1902, which had a four-cylinder engine and was capable of pulling a ten-furrow 14-inch plough. However, the first production tractors did not appear until 1912 - initially known as just the "Wallis Tractor", they carried a rating of 30-50 hp and weighed 16,000 pounds. The engine design, with four 6.5 x 8 in cylinders cast in pairs, had been patented by Henry L.F. Trebert in 1911. The rear wheels were 7 feet in diameter and the front wheels 42 inches, and the three-wheeled design allowed it to turn within its own wheelbase of 12 feet. Three forward speeds and one reverse were provided, and the transmission was enclosed in dust-proof casings. The fuel tank held 60 gallons and the large tubular radiator at the front of the radiator contained 460 feet of tubing! The tractor was provided with power steering via a pair of friction cones, and was also sprung front and rear. Advertising literature of the time mentioned that it could also be adapted for use as a road-roller.
http://www.steel-wheels.net/wallis.html
