1723. Of wheel turf-rasers, or verge-cutters, or edging-irons, there are various kinds; one in use by the French is shown in fig. 356.; and another, invented by Mr. Mac Intosh, in fig. 357. With Mac Intosh's verge-cutter, a man may cut as much in one day as he will cut in four or five days with the one in general use. Unless there be a long straight, line to be edged, a garden line is unnecessary; but when one is used, it may be placed between the wheel and the coulter, or cutting part, of the machine (a). A certain degree of pressure is necessary on the handle, when the ground is hard; and the kneed coulter (b) may be employed where the edgings are not very regular. When in use, the coulters should be sharpened every morning, and several should be taken out by the operator, in order that the instant one loses its cutting edge, its place may be supplied by another. (Gard. Mag. vol. i. p. 139.) Bell's turf-raser (fig. 358.) is adapted to places where the surface is hilly or uneven; and its advantages are, first, that it cannot be pressed into the ground, the broad and circular-formed part (a), that is pressed upon, preventing its entering the ground, however soft the same may be; whilst the same curvilinear form enables it to ride freely (as the workmen term it), requiring but comparatively little force to drive it: secondly, two knives accompany this implement, of different lengths, which can be taken out and replaced in a few seconds, by removing the bolt (b); thus enabling the workmen to have the knives in good working order at all times; and, thirdly, by the adjusting screw (c), placed at the back of the knife (d), it can be set to cut any depth; and, consequently, one great disideratum is obtained, as any required thickness of turf can be taken up; a matter of much importance where very neat work is required.