=198. Fruit and Vegetable Parers with Knives.= Parers of the type with a knife have a fork-like device on which the fruit or vegetable is held while a knife blade, attached to a shaft governed by a spring, is pressed against the fruit or vegetable so that it cuts off a thin layer of the surface. Both the fruit and the knife are caused to rotate so that the whole surface of the sphere-like object will be covered by the blade of the knife during one or more revolutions of the wheel which operates them (Fig. 107). The knife is guarded so that it cuts only a thin layer from the outer surface of the fruit or vegetable. After the knife has made the complete journey over the surface, a device attached to the machine pushes the object from the fork so that a new one may be put in its place. Parers are quite complicated devices, but they have been perfected so that they are not clumsy, and some can core apples, stone peaches and slice the fruit. [Illustration: FIG. 107. Parer.] Keep this type of machine dry so that it will not rust. Do not put it into water. Wipe off the blade of the knife and the fork when thru paring, so that the acid of the fruit will not discolor them and dull the knife. Keep the other parts dry and oiled. In time the spring governing the knife becomes weak and the machine will not do good work. This spring can be replaced on some machines. Parers are usually made of cheap material so that a new machine costs less than the repairs. =199. Parers Which Grate Off Skins.= Another type of parer is a grater-like device. This is used in larger establishments than the ordinary home, but is useful where there is much canning of hard fruits or vegetables to be done at home. It consists of a container, the inside of which is rough like a grater. The vegetables or apples are put into the container with water enough to float and separate them, and the whole is agitated so that the vegetables coming against the sides have the outer surface removed or grated off. The water acts as the medium for moving the vegetables and for removing the bits of skin from the sides of the parer. [Illustration: FIG. 108. Cherry stoner.] [Illustration: FIG. 109. Grinder.] Keep this parer clean by scrubbing the inside with a stiff brush and rinsing well with water after using. Keep in a dry place. =200. Seeders and Stoners.= Seeders and stoners are constructed to punch out the seeds which are contained in cherries, grapes, raisins, etc. [Illustration: FIG. 110. Parts of Corona grinder.] =201. Cherry Stoner.= A simple cherry stoner (Fig. 108) consists of a small platform with a rod slightly smaller in diameter than a cherry stone. The cherry is put on an inclined plane so that it rolls over the hole. The cherry usually stays on the rod until this rod is lifted; then it passes between two guards which pushes the cherry off on another incline, where it rolls into a pan (Fig. 108).