Need of Governors. Plowing. In order that a tractor may be Operated most economically, it must be capable of one-man control since, in plowing, conditions are continually encountered Where the driver's attention must be centered on the management of the plows and the steering of the machine to the exclusion Of everything else. Moreover the demands upon the engine are con tinually varying even when the soil conditions are apparently uni form for long stretches. Stones, roots, and extra heavy patches of sod all impose considerable extra load on the engine that can be met satisfactorily only by an automatically controlled throttle if a uniform plowing speed is to be maintained. Belt Work. A far greater load variation is encountered in belt work than in plowing, as in the former the engine may be running practically idle at one moment and be almost choked down by overloading the next, whereas in the latter there is always a load on the engine and therefore the danger of racing is absent. Irregular speed under changing load, racing of the idle engine, and tardy Opening of the throttle to meet the increased load, all of which are unavoidable with hand control, represent conditions of operation which not only reduce production at the machine being driven but are very bad for the engine itself as they result in overheating, prevent proper lubrication, and, not infrequently, result in bumed-out bearings. In any case the pro vision of a governor on the engine releases a hand for other and more productive labor. The majority Of tractors go into service in the hands of an unskilled operator, and unless there is a governor on the engine, his course of instruction is likely to be marked by the occurrence of more or less damage that automatic control would prevent.