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A Marshall's agricultural hydraulic gear tractor. The fuel tank is located on the bottom back of the tractor, while the water tank is under the driver's seat. The back wheel is turned by the engine.

Marshall's Agricultural Hydraulic Gear Tractor

A Marshall's agricultural hydraulic gear tractor. The fuel tank is located on the bottom back of the…

"In this machine a petrol or paraffin engine drives a water—ballast roller through the medium of a clutch, a simple form of change—speed gear—box, and a single roller chain. The leading roller, by which steering is effected, is also filled with water, in order to obtain the dead weight necessary for rolling." —Encyclopaedia Britannica, 1910

Thornycroft Military Oil Tractor

"In this machine a petrol or paraffin engine drives a water—ballast roller through the medium…