"The Gray Gasoline Engine , constructed by the Gray Motor Company of Detroit, Michigan, is of the four-cycle, stationary, hopper-cooled type, especially designed for farm use. It is built in four sizes 1-1/2 horse power, 2-1/2 horse power, 4 horse power and 6 horse power, which manufacturers claim are those most commonly demanded for agricultural purposes."
Gas Engines For the Farm, Copyright 1913, C. F. Hirshfeld and T. C. Ulbricht.
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