four inches wide, and the drain covered with the sods first dug out, if the ground be firm enough to support them; or, some black-thorns are put in, in order to bear the weight of the sods. Those drains which have the smallest passage for the water at the bottom, are reputed to be the most durable; as the force of the water has been found sufficient to clear away any small obstacles accidentally obstructing its course.
Common earth-drains are sometimes dug two or three spits deep, with a broad spade, the bottom is taken out with a narrow one, and filled with stones.—Sometimes a furrow is drawn with a plough, and cleared by a common spade: the draining instrument Fig. 1, is then introduced to the depth of 18 inches from the surface; and, after taking out the loose mould with the scoop Fig. 2, black-thorn bushes, or heath, which is still better, are carefully laid along the bottom, covered with strong wheat-straw, twisted to the thickness of a man's leg; and the whole is then carefully closed in.
Hollow drains, without stones, have been tried on stiff lands: they are made narrow at the bottom, and covered half way up with sods, or square pieces of the surface-sward, resting on ledges cut for that purpose.
It is much to be lamented, that we possess, in this cold climate, no grain similar to rice, that would grow in watery grounds which cannot be drained, nor indeed any esculent roots or foliage, except water-cresses. In such situations, some plants may perhaps be cultivated with profit to the proprietor, as the Festuca fluitans, or Floating Fescue; Callitriche, or Star-grass, or Star-wort; to which may be added the Orchis, for the purpose of making salep, by drying the peeled roots in an oven. If these plants should not completely succeed, other vegetables of quick growth may be raised for manures, such as the Typha, or Cat's-tail; the Caltha, or Marsh-marigold, &c.; which should be mown twice a year, while they are young, and abound with saccharine and mucilaginous matter, ready to pass into fermentation.
It frequently happens that, notwithstanding all the labour and expence which the industrious cultivator may bestow on the construction of drains, his lands become, in the course of time, soft and wet, so that they gradually return to their former state. This unfavourable change is often occasioned by the Eqiusetum palustre, or Marsh Horse-tail, a plant growing on swampy ground, which has been
