continued flowing ever since, tho' with less rapidity.
These ditches should be made narrower as they descend, by spades of a proportionate sise and breadth: but the lowest part ought to be contracted more than any other, so that the shoulders or edges of it may support stones or faggots, in order to cover the whole, at a small expence, without obstructing the currents of water. In many places, hollow-bricks, ridge-tiles, or old fragments of plastered floors, may be applied to the same purpose; as they may be substituted for stones, or faggots, and at a reduced expence.
Situations, however, frequently occur, where the first stratum of the earth may be too thick to be easily perforated; or where the water, condensed from the atmosphere on the summits of the hills, may work itself a passage between the second and third, or between the third and fourth strata, which form the sides of those hills, from a deficiency of so many of the strata at their summits. Hence the water lies too deep to be retarded in its progress by a ditch, or by boring; but, being dammed up by the materials that form the plain of the valley, it ascends through them to the surface, and thus forms boggy, or marshy ground. In such cases, the common mode of draining may be successfully employed: it consists in cutting several ditches four or six feet across the bog, or morass; and in covering them so that the water may not be obstructed in its passage, but be thus in part collected and conveyed away, though certainly with less advantage than where springs can be intercepted.
Another method of draining is, that of opening thenches, or drains, almost annually, by a large plough with two converging coulters, and other appropriate machinery, for the purpose of cutting both sides of a ditch at the same time, and turning out the intervening soil.—These large ploughs are still kept in some parishes, and drawn over moist commons, by twelve or twenty horses, so as to form parallel ditches.
An instrument was invented for this purpose by Mr. Adam Scott, of Guildford, Surrey, called by him, a mole-plough, and for which the Society for the Encouragement of Arts, &c. in 1797, gave him a bounty of thirty guineas. It consists of a coulter, 15 inches in length, and 212 in width, to cut the sward. Behind this is applied an horizontal cone of cast iron, 20 inches long, and 212 in diameter at the base, to the middle of which is fixed an upright bar 2 feet long, and 312 inches broad, with a sharp edge. If this cone be drawn along moist lands, 6 or 8 inches beneath the turf, either in the spring or in autumn, in several parallel directions, the water will be conveyed away for a considerable space of time, without breaking the surface. With Mr. Scott's mole-plough, a man and boy with four horses may, with ease, drain thirty acres in a day; but, at the lower side of the ground intended to be drained, there should be made an open gripe or ditch, in order to receive the water from those small cavities which are formed by the plough, at the depth of 12 or 14 inches. In very moist lands, or in very wet seasons, if a larger number than six or eight horses be employed, their feet will not sink so deeply into the turf as each animal will
