[Illustration: Figure 166.--Sand Caps. Not one manufacturer in a hundred knows how to keep sand out of an axle bearing. Still it is one of the simplest tricks in mechanics. The only protection an axle needs is long ferrules that reach out three or four inches beyond the hub at both ends. Old-fashioned Linchpin farm wagons were built on this principle. The hubs held narrow rings instead of skeins, but they wore for years.] BOBSLEIGHS On Northern farms bobsleighs are as important in the winter time as a farm wagon in summer. There are different ways of putting bobsleighs together according to the use required of them. When using heavy bobsleighs for road work, farmers favor the bolster reach to connect the front and rear sleighs. With this attachment the horses may be turned around against the rear sled. The front bolster fits into a recessed plate bolted to the bench plank of the front sleigh. This plate is a combination of wearing plate and circle and must be kept oiled to turn easily under a heavy load. It not only facilitates turning, but it prevents the bolster from catching on the raves or on the upturned nose of the front bob when turning short. The heavy hardwood plank reach that connects the two bolsters is put through a mortise through the front bolster and is fastened rigidly by an extra large king-bolt. The reach plays back and forth rather loosely through a similar mortise in the other bolster on the rear sleigh. The rear hounds connect with the reach by means of a link and pin. This link pushes up through mortise holes in the reach and is fastened with a wooden pin or key on top of the reach. Sometimes the hounds are taken away and the reach is fastened with pins before and behind the rear bolster. This reach hitch is not recommended except for light road work. These two ways of attaching the rear sled necessitate different ways of fastening the rear bolster to the sled. When the rear bolster is required to do the pulling, it is attached to the sled by double eyebolts which permit the necessary rocking motion and allows the nose of the rear sled to bob up and down freely. This is an advantage when a long box bed is used, because the bolster is made to fit the box closely and is not continually oscillating and wearing. Eye-bolts provide for this natural movement of the sled. Light pleasure bobs are attached to the box with eyebolts without bolster stakes. The light passenger riding seat box is bound together with iron braces and side irons so it does not need bolsters to hold the sides together.