_a._ The plug, or point under ground, to which the string of pipes is attached. _bb._ The coulter from the point up through the beam, regulated by wheel and screw midway. _c._ The beam connecting the two pairs of wheels. _e._ Drain opened by hand where pipes enter the ground. _a to e._ Pipes under ground. _e to f._ Pipes above ground. _g._ Windlass or capstan, worked by horses. _h._ Wire rope attached to plow, and wound round the windlass. _i._ Pulley round which the rope runs to keep the plow in the line of the ditch.] DRAINING-PLOWS AND DITCH-DIGGERS. The man who can invent and construct a machine that shall be capable of cutting four-foot ditches for pipe-drains, with facility, will deserve well of his country. It is not essential that the drain be cut to its full depth at one operation. If worked by oxen or horses, it may go several times over the work, taking out a few inches at each time. If moved by a capstan, or other slowly-operating power, it must work more thoroughly, so as not to consume too much time. With a lever, such as is used in Willis's Stump Puller, sufficient power for any purpose may be applied. An implement like a subsoil plow, constructed to run four feet deep, and merely doing the work of the pick, would be of great assistance. Prof. Mapes says he has made use of such an implement with great advantage. For tile-drains, the narrower the ditch the better, if it be only wide enough to receive the tiles. A mere slit, four inches wide, if straight and of even inclination at the bottom, would be the best kind of ditch, the pipes being laid in with a pipe-layer. But if the ditch is to be finished by the machine, it is essential that it be so contrived that it will grade the bottom, and not leave it undulating like the surface. Fowler's Drain Plow is said to be so arranged, by improvements since its first trials, as to attain this object. Having thus briefly suggested some of the points to be kept in mind by inventors, we will proceed to give some account of such machines as come nearest to the wants of the community. Fowler's Draining-Plow would meet the largest wants of the public, were it cheap enough, and really reliable to perform what it is said to perform. The author saw this implement in England, but not in operation, and it seems impossible, from inspection of it, as well as from the theory of its operation, that it can succeed, if at all, in any but soft homogeneous clay. The idea is, however, so bold, and so much is claimed for the implement, that some description of it seems indispensable in a work like this. The pipes, of common drain tiles, are strung on a rope, and this rope, with the pipes, is drawn through the ground, following a plug like the foot of a subsoil plow, leaving the pipes perfectly laid, and the drain completed at a single operation. (See Fig. 88.)