Page:Encyclopædia Britannica, Ninth Edition, v. 1.djvu/345

Rh IMPLEMENTS.] AGRICULTURE 319 kind, but a much better implement is Cartwright s chain- harrow, which abrades the surface over which it is drawn to a degree that could not be anticipated from a mere inspection of the implement. It is formed by attaching to a draught-bar pairs of square-linked chains, each 7 feet long, connecting them by cross links, and keeping the whole expanded by two movable stretchers. The old-fashioned ponderous break harrow is now entirely discarded, and the more efficient cultivator used in its stead. A form of the latter, from its close resemblance to harrows, is noticed now rather than before. It is a very strong iron harrow, with the tines made longer, and very considerably curved forwards. An iron rod with a loop handle is fixed to the hind bar, by means of which the driver can easily hitch it up and get rid of weeds, &.c. Two such harrows are coupled together and drawn by four horses. Its pulverising power is very considerable. But when clods have been brought to the surface, they are most effectually reduced by various kinds of rollers. Section 6. Rollers. Those formerly used were solid cylinders of timber or stone attached to a frame and shafts, for which hollow ones of cast-iron are now generally substituted. The simplest form of these has a smooth surface, and is cast in sections to admit of more easy turning. They are made of diverse weights, so as to be adapted for the draught of one or two horses as required. Those of the former description,weigh- Cambridge s roller possesses several features in common with Crosskill s, and is used for similar purposes. In the Smooth Cast-Iron Field Roller. iiig in all G cwt., and costing as many pounds sterling, are exceedingly useful for all purposes where expedition rather than heavy pressure is wanted. From their greater dura bility, smoother surface, and less liability to clog, the readi ness with whica they can be cast of any weight that is re quired, and their moderate price, it is probable that cast-iron cylinders will speedily supersede all others. Several important variations on the common smooth roller have been introduced of late years. Of these the first notice is due to Crosskill s clod-crusher, on the ground both of its intrinsic merit and the date of its introduction. It consists of cast-iron discs 2 feet in diameter, with serrated edge and a scries of side way-projecting teeth. Twenty-three of these discs are strung loosely upon a round axle, so as to revolve independently of each other. The free motion thus given to each disc, and which has latterly been increased by cast ing each alternate one of greater diameter in the eye, adds at once to the pulverising and self-cleaning power of the roller. Three horses yoked abreast are required to work it. The axle is prolonged at each end sufficiently to receive travelling wheels, on which it is transported from place to place. Although primarily designed and actually much used for breaking clods, it is even more in request for consolidating loose soils, checking the ravages of wire-worm, and covering in clover and grass seeds. For the latter purpose, its action is perfected by attaching a few bushes to it, which fill up the indentations, and leave a surface so beautifully even as to rival the accuracy and neatness of a well-raked border. It is now to be had on a smaller scale adapted to the draught of two horses. Canil i-M-e s Press- Wheel Roller. form in which it was first brought out it consisted of discs, fitting close to each other, with fluted instead of serrated edges. In its recently improved form the discs are not made of uniform diameter as formerly, but each alternate one in the set is raised about two inches, and has the centre hole, not circular and close fitting to the axle, but triangular and wide. The result is that while the discs press uniformly on the surface over which they are rolled, the larger ones rise above their fellows with a jerking motion, Avhich gives a most efficient self-cleaning power to the implement, and thus admits of its being used when other rollers would bo clogged. The eccentric discs are now made either with OO serrated or smooth edges as customers prefer. After careful trial we have come to the conclusion that it is the most useful roller for general purposes which we yet possess. Disc ol Cam bridge s Roller, showing Self-cleaning Action. Under this head may be noticed press drills, which, by means of a series of narrow cylinders with conical edges, form corresponding grooves in loose soil. Seeds sown broad cast ove. a surface thus treated come up in rows. The Land-Presser. land-presser is a modification of the press-roller. It is made with two or three conical edged cylinders to fit into the seams of as many plough furrows, the other end