1902 Encyclopedia > Agriculture > Grubbers, etc.

Agriculture
(Part 18)




VI. MACHINES AND IMPLEMENTS OF HUSBANDRY (cont.)

Grubbers, etc.


Next in importance to the plough is the class of implements variously called grubbers, cultivators, drags, or scarfiers. To prepare the soil for the crops of the husbandman, it is necessary to pulverize it to a sufficient depth, and to rid it of weeds. The appropriate function of the plough is to penetrate, break up, and reverse the firm surface of the field. This, however, is only the first step in the process, and does but prepare for the more thorough disintegration which has usually been accomplished by harrowing, rolling, and repeated ploughings. Now, however excellent in its own place, the plough is a cumbrous and tedious pulveriser, besides needlessly exposing a fresh surface at each operation, and cutting the weeds into minute portions, which renders their removal more difficult. These defects were long felt, and suggested the desirableness of having some implements of intermediate character betwixt the plough and harrow, which should stir the soil deeply and expeditiously without reversing it, and bring the weeds unbroken to the surface. The whole tribe of grubbers, &c., has arisen to meet this demand, and we shall now consider the comparative merits of the more prominent of the group. The first notice is due to Finlayson’s harrow, which, as improved by Scoular, was, until recently the best implement of its kind. Its faults --- and they attach equally to Kirkwood’s and Wilkie’s --- are, that it is severe work for two horses, is liable to choke in turfy or foul ground, and that is consolidates the bottom of the furrow, while producing a fine tilth on the surface. Finlayson’s grubber, in its improved form, weighs about five cwt., and costs as many pounds.

Another useful implement of this class which enjoys a large reputation in England is Biddle’s scarifier. It is mounted on four wheels --- two small ones in front and two much larger behind. The frame and tines are of cast-iron, and can be raised and depressed at pleasure by means of two levers which regulate the depth to which the tines shall penetrate. The tines are prepared to receive case-hardened cast-iron points of different widths, or steel hoes of nine inches width, so that the implement can be used for breaking up and paring the surface, or for grubbing out weeds and pulverizing the soil, as may be required. An important feature in this scarifier is, that it keeps its hold of a hard surface much better than a plough. It weighs half a ton, is drawn by four or six horses, and costs about £18.

The Ducie or Uley cultivator has many features in common with Biddle’s, and although brought forward as an improvement upon it, has not establish its title to be so regarded. The great weight, high price, and amount of horse-power required to work them, are serious objections to all these implements.

Of more recent notoriety than these, and contrasting with them favorably in these respects, is an implement invented by the late Mr. John Tennant, at Shields, near Ayr, and now popularly known as Tennant’s grubber. Its construction, as the annexed cut will show, is simple in the extreme. Its weight is about two cwt., its price £4, 10s., and its draught easily overcome by two horses. The depth at which it works is regulated by raising or lowering the shank which supports its wheels in front. Its tines can be easily moved on their supporting bars, and it may be worked with five or seven as desired. By substituting a shorter hind bar, and setting the tines more closely together, it makes a most efficient drill-grubber. We shall have occasion to refer to this implement frequently in treating of tillage operations. The improvement which Mr. T. Brown has made on Tennant’s grubber consists mainly in the mode of attaching the tines to the bars. This attachment, which the cut explains, has the merit of being at once very simple and very effectual. The times when thus fixed are as rigid as if welded to the bars, and yet, by merely slackening the screws and driving out the wedged, they can with ease and rapidity be either adjusted in varying widths apart, or detached for repair.






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