Page:Encyclopædia Britannica, Ninth Edition, v. 1.djvu/338

Rh 312 AGRICULTURE [MACHINES AND or bulking plough for drilling. An important feature in the English ploughs is, that they are fitted with cast-iron shares, which, being case-hardened on their under surface, wear unequally, and so preserve a sharp edge. The necessity for daily recourse to the smithy is thus removed, and along with it that irregularity in the quality of the work and draught of the plough, which so often arises from witting or unwitting alterations being made in the set of the share in the course of its unceasing journeys thither. These cast-iron shares are slightly more brittle than those made of malleable iron with steel points ; but it is of importance in determining their comparative merits to bear in mind that the prime cost of the former lOd. to Is. each is so small as to render them at the year s end the least expensive of the two. When it is desired to turn a very deep furrow, a plough is used differing from the common one only in being somewhat larger and stronger in all its parts, with four horses to draw it. Ploughs which break and stir the subsoil, without bringing it to the surface, by following in the wake of the common plough, are now much used. The first of the kind the invention of the late Mr Smith of Deanston is a ponderous implement, requiring at least four good horses to draw it. It is well adapted for displacing and aiding in the removal of earth-fast stones. The inventor has happily described its operation by terming it a &quot; horse pick.&quot; Read s subsoil- plough is a much lighter implement, which can usually be drawn by two horses. Since the introduction of thorough draining, it is found beneficial to loosen the soil to a much greater depth than was formerly practicable, and this class of implements is well fitted for the work. It is always ad visable to use this implement, and to mark and dig out the large stones encountered by it, before introducing steam cultivation. Broadshare or paring-ploughs are much used in various parts of England in the autumn cleaning of stubble. A broad-cutting edge is made to penetrate the soil to the depth of three or four inches, so as to cut up the root- weeds which at that season lie for the most part near the surface. These, as well as the stubble, being thus detached from the firm soil, are removed by harrowing and raking ; after which the land is worked by the common plough. An implement of this kind is frequently used in carrying out the operation of paring and burning. Bentall s Broadshare has the reputation of being the best of its class ; but we can con fidently recommend the common plough, stripped of its mould-board and fitted with a share twelve inches broad, as not only the cheapest, but decidedly the most efficient scarifier that has yet been used. An ingenious Aberdeenshire mechanic, Mr Pirie of Kinmundy, has recently invented a double-furrow plough, on an entirely new principle, which has met with general approval, and has already been adopted by all the great plough makers. By carrying the plough on three wheels, one on the land and two bevelled ones in the angle of the furrow, Mr Pirie dispenses with both soles and side plates, and thereby lessens the friction, and avoids that hurtful glazing and hardening of the bottom of the furrow which attends the use of other ploughs. So much is the draught lessened by this improvement, that three horses and one man with this double-plough can perform as much work in a day as four horses and two men with two ordinary ploughs. For a seed-furrow or level field of free soil, two horses are quite able to work the double- plough. Various implements of the plough type, so modified as to adapt them for particular processes, have from time to time been offered to public notice, but have failed to meet with general favour. We limit our notice to those of ascertained utility, and refer the reader who desires fuller information to Ransome s Implements of Agriculture, 1 and the more recent work by Messrs Stephens and Scott Burn, where he will find descriptions of the most interest ing of them. Section 3. Grubbers, d~c. Next in importance to the plough is the class of imple ments variously called grubbers, cultivators, drags, or scari fiers. To prepare the soil for the crops of the husbandman, it is necessary to pulverise 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 pul veriser, 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 implement 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 it 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 Kiddle s Scarifier, as made by Ilaiisoine & Co. 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 pulverising the soil, as may be required. An important feature in this scarifier is, that it keeps its hold of a hard sin-face much better than a plough. It weighs half a ton, is drawn by four or six horses, and costs about 18. 1 The Implements of Agriculture, by J. Allen Ransome, Lond. 1843. The Look of Farm Implements and Machines, by Henry Stephens and R. Scott Burn. Edin.