The change speed gears of a tractor should not be shifted while in motion, this being one of the differences between a tractor and an automobile. In the sliding gear type of change speed mechanism, the gears slide into mesh sideways, a tooth of one being opposite a space between two teeth of the other. If the gears are not in the right position for this, one tooth will strike another, and the gears cannot be meshed. In such a case the clutch is let in for a slight touch to move one gear, not for a dozen or twenty revolutions, but enough to bring a space between two teeth of one gear opposite a tooth of the other. If an attempt is made to shift the gears while they are in motion, the result will be that one will grind against the other, and there will be rapid wear and probable breakage. It is because gears cannot be shifted while they are moving that manufacturers instruct users not to attempt to shift on a hill without first blocking the wheels. The reason for this is that the brakes may not hold the tractor, and if the gears are pulled out of mesh, the machine may start to run down hill; as another speed cannot then be engaged because the gears are moving, there will be no control over the tractor. Never coast down hill; always run with one of the speeds engaged. By switching off the ignition the motion of the tractor will drive the engine, and this provides the best possible brake. On low gear, the engine will turn in the neighborhood of eighty revolutions to one turn of the driving wheels, and the work required to do this will check the tractor on the steepest of practicable grades. A tractor is not built for as accurate and delicate steering as an automobile and should always be slowed in making a turn; this is especially true when hauling plows or other loads in the field. It is difficult to control the tractor if a turn is made at high speed, and the machine is liable to tip over. In steering and in engaging the clutch, the action should not be jerky and abrupt, but gradual and smooth. Letting in the clutch suddenly will start the tractor with a jerk that will strain it from end to end, and an abrupt swing of the steering wheel will have the same effect. Making these motions smoothly and steadily will cause the tractor to change its direction or pace with the least possible strain and effort. This, of course, increases the tractor’s life. In much of the work done by the tractor, the varying conditions of field and soil make a continual change in the load, and the tractor must be handled accordingly. The change from an uphill to a downhill haul, and from sand or light loam to gumbo, will require the gears to be shifted in order that the engine may neither labor nor race in keeping the outfit at its work.