163. Self-Rake Reaper.-All harvesting machines have certain features in common. These are the serrated sickle vibrating through stationary guards, a platform to receive the cut grain, some provision to bring the grain regularly against the sickle and deposit it on the platform, a divider to separate the swath

The self-rake reaper.

to be cut from the remainder of the standing grain, and some means by which the operator can quickly raise or lower the cutter bar while the machine is in motion.

In the self-rake reaper the platform has the form of a quarter of a circle,

and upon it operate automatically rakes which serve the double purpose of bringing the grain onto the platform and removing it from the platform far enough to one side so that the reaper can again pass around the field without running over the cut grain. The size of the bundle is determined by regulating the number of rakes

which remove the grain. Because of the necessity of binding the grain by hand, they are used only where small quantities are to be harvested. The reaper cuts a swath of five feet and is drawn by two horses. An ordinary day's work is from six to eight acres.

164. The Self-Binding

Harvester. By far the larger area of small grain is now harvested by this machine, generally called the "binder."

They are manufactured in a number of styles, but in their essential features they are nearly all practically identical. It differs from the reaper in having a reel to bring the grain against the cutter bar and deposit it on the platform. This reel is attachable at the will of the operator while the machine is in motion. The cut grain is conveyed on an endless canvas to an elevator consisting of two endless canvases which deposit the grain on the opposite side of the drive wheel, where it is packed into a trim bundle and automatically bound with twine. The binding device operates as often as the pressure of the increasing bundle trips it. The size of the bundle is therefore determined by regulating the pressure required to trip the binder. Binders are made which cut different widths, the standard width being six feet.

Three horses are used with the sixfoot cut, and an ordinary day's

work is from ten

to twenty acres,

The header.

depending upon many factors, the most important of which are the yield and the condition of the straw.

165. The Header.—The header and the combined harvester can be used only where the climate is such as to permit harvesting the wheat after it is fully ripe and thoroughly dry, and hence are in use only in the western half of the United States. Instead of cutting the wheat near the ground, they merely head it, leaving the bulk of the straw standing in the field. The header conveys the headed grain to the side of the machine and elevates it so that it is deposited in a wagon driven along. side to receive it. The grain is either immediately carried to a threshing machine or first put in stacks and subsequently threshed.

still larger machines, cutting a swath twenty-five or more feet in width and operated by steam power, and doing a correspondingly larger amount of work.

167. Threshing.-In some sections of the country the wheat is mostly threshed directly from the shock, while in other sections it is first stacked or stored in the barn and after the grain has had time to go through the sweat, it is threshed. There is little more danger of the threshed grain heating in the bin if threshed directly from the shock, but where care is taken to have the grain thoroughly dry, heating will not occur. Under such circumstances, there is no material difference in the quality of the grain or of the resulting flour. Probably much of the larger part of the wheat harvested in the United States is threshed directly from the shock. Rainy weather may cause damage, which can be guarded against in some measure by storing in barn or by stacking, but ordinarily it is largely a matter of economy and convenience. The sprouting of wheat not only greatly decreases the quality of the grain, but it has been shown that sprouting wheat for six days or until grains are beginning to burst their first leaf, may cause a loss of twelve per cent in weight. A few farmers own their own threshing machines, and very rarely a machine is permanently located in the barn in accordance with the English custom. Ordinarily, however, the threshing is done by the itinerant steam threshing outfit which does the work for a stated price per bushel. Usually 500 to 1,000 bushels are threshed per day.

168. Storing. The principal things to be considered in the storing of wheat are the ease of handling, freedom from dampness, insects and vermin. Wheat is not injured by cold, and insects injurious to wheat do not thrive at cold temperatures, consequently the more exposed the granary the better. The larger the bulk of grain and less the exposure of the surface, the less will be the injury from insects. The surface of the rooms and 1 Ark. Bul. 42 (1896), p. 72.

bins should be constructed so as to prevent lodgment of insects, as far as possible, by having smooth surfaces which are preferably