rocks, blasting of.
LIEUT. Wainhager, a German, has discovered that saw dust, particularly of soft wood, mixed with gun powder, in equal parts, has thrice the strength of powder alone, when used in blowing rocks.
rollers.
THE roller is the most useful implement for breaking hard clods expeditiously, and smoothing the surface of land when in tillage, ever yet invented. It is likewise of use to grass lands laid down for hay; and heavy rollers would prevent those ant hills, by which so many pastures are deformed. Rollers are made of various substances; as wood, freestone, granite or cast iron; but on the whole the two latter are to be preferred. It is of importance, that the weight of the roller should be in proportion to the surface on which it is to be employed. The best plan, is that of having two rollers, each about two feet and an half in length, and both placed in one frame, so as to roll clear of one another. This is the most suitable both for corn crops and sown grass, as it neither tears up the tender soil, nor injures the young plants. Besides the labour in turning is much less severe on the frame and on the cattle Every farm ought to be provided with rollers of different diameters and weights, so as to suit the several purposes to which they are destined; those of a small diameter are generally applied to land in tillage; and those of a large diameter, with double shafts, to grass land. Heavy rollers are of great use, for destroying worms, slugs and other vermin in the soil.
An intelligent farmer maintains, that if draining is the first, manuring the second, and cultivation the third, rolling ought to be considered as the fourth
