A gas tractor can be started in a very few moments while the engineer of a steam rig has to start in an hour or more before the crew to get steam up, etc. In addition to this there is the usual tedious routine of “oiling up,” cleaning the flues, etc. There is absolutely no danger of explosions with the gas engine which have proved so disastrous in the past with steam threshing engines. With the gasoline, the operator is left free to work on the separator as he has no firing to do and does not have to concentrate his attention on keeping the water level at the correct point in the gauge glass. The engine is automatically lubricated in all cases so no attention is demanded on this score for it will run smoothly hour after hour without the least attention. This feature eliminates one high priced man from the job. On heavy loads the problem of keeping up the steam pressure is often a vexatious one, especially if a poor grade of coal is used. With a lower priced man as operator tending both the separator and the gas engine the crew need only consist of two pitchers to feed the machine, with a man and team for each pitcher. This small crew is easily accommodated at the farmers house, and does not require the services of a separate cook and camp equipment. With a gasoline rig the expenses will be approximately as follows: Engineer, wages and expenses $ 5.00 Two pitchers, at $3.00 6.00 Four men and teams 20.00 60 gallons of gasoline at 15c 9.00 Lubricating oil 1.00 —————— Cost per day $41.00 Taking 1,500 bushels (wheat) as a day’s work, the cost of threshing figures out at 2¾ cents per bushel. According to data furnished by the M. Rumely Company, which is based on an actual test, the total cost of plowing, seeding, cutting and threshing, including ground rental and depreciation, amounted to $8.65 with horses and $6.55 with their oil tractor. These figures will of course vary in individual cases, but are principally of interest in showing the comparative cost of horse and tractor operation. With a gasoline or oil tractor equipped with engine plows one man can tend to both the plows and the engine, although some operators prefer to have two men, one relieving the other consequently plowing more acres per day and reducing the cost per acre. In some cases one man is placed on the plows and the other on the engine. By running the tractor twenty-four hours per day, with two shifts of men, a much better showing is made by the tractor when compared with horse plowing, for with the latter method it would be necessary to supply twice the number of horses. To show the relative merits of various grades of fuel we will print the data kindly furnished by Fairbanks Morse for a ten hour day.