406 



SCIENCE OF AGRICULTURE, 



Part II. 



and the operation is repeated at intervals till the crop is thoroughly cleaned. The 

 centre hoe is stationary, and the right and left expand and contract in the same manner 

 as in the horse hoe. The deptli is regulated by the wheel at the point of the beam, and 

 may be varied from one to six inches. The hoes cut the bottom of the space between 

 the drills completely, while the harrow following, pulverises the soil, and rakes out the 

 weeds. Should circumstances require, the wings of the harrow may be taken off", and 

 the hoes only used ; or the hoes displaced, and the harrow only employed. This imple- 

 ment was invented by the late Mr. Wilkie of Uddingston, near Glasgow, in 1820, and 

 is the first instance of the cycloid form being adopted in hoes or prongs. Afterwards 

 Mr. Finlayson applied this form to his harrow; and subsequently Mr. Wilkie, junioi, of 

 Uddingston, to his admirable brake (2655. ) 



2667. Finlayson s self-cleaning horse hoe and drill harrow {Jig. 331.) is an excellent 



implement, and as a harrow is preferable to that of Wilkie (2665. ) from whose imple- 

 ment it differs chiefly in being more a harrow than a hoe, and in every prong being 

 calculated for cleaning itself. 



2668. Wilkie s horse hoe and drill plough is considered an effective implement. The 

 mould-boards are taken off when used as a horse hoe, and the hoes taken oft" and the 

 mould-boards replaced when earthing up the crops ; thus combining, in one implement, 

 a complete horse hoe and double mould-board plough. A good horse hoe being the 

 principal object in the construction of this implement, the method of fixing the hoes 

 claimed particular attention, in order to combine lightness with strength and firmness, 

 and admit, at the same time, of being set at different degrees of width and depth, all of 

 which are accomplished on an improved principle. The wheel at the point of the beam 

 regulates the depth ; the right and left hoes are hinged, at the back end, to the handles 

 of the plough, while by moving on the circular cross bar, on which they are fastened 

 with wedges, they may be set to any width, from about twelve to nearly twenty-four 

 inches. 



2669. Weirs expanding horse hoe bears a considerable resemblance to Wilkie's imple- 

 ment. It has circular coulters, hoe-tines, and a doable mould-board. When used for 

 earthing up potatoes, the mould-boards and coulter are put on ; when used as a hoe, the 

 cvu-ved coulters are put in the expanding bar according to the width between the rows. 



2670. Blakie's inverted horse hoe [Jig. 332.) consists of a line of coulters set in a beam, 

 and this beam attached to 

 the axle of a pair of com- 

 mon wheels. It hoes seve- t=::;:-0"s^ 332 

 ral rows at once, and instead 

 of being straight the coulters 

 are all curved or kneed, and 

 set back to back so as to 

 include a row between each 

 pair. The advantage of the 

 kneed or bent form of the 

 lower part of the coulter is, 

 that the soil is pared off" in a 

 sloping direction from the 

 plants, which are thus not 

 so liable to be choked up 



with earth, as by a broad hoe _ 



or share ; or to have their roots so much exposed to the air as by cutting perpendicularly 

 oown close to the row, by a common coulter. It is chiefly adapted for drilled corn, and 

 then It works several rows : in turnips it may work one or two according to the soil ; in 

 all cases where the width between the rows admits, the agricultor should be more anxious 



