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height, and the third one equal to 2 ft. added to the depth of the drain. The two shorter ones are held perpendicularly, one at each end of the drain, upon the surface of the ground, while the long one is shifted along the bed of the drain, and the prominent or depressed points marked for correction. Besides these staves, a common mason's level, with a plumb line, is a very useful instrument for testing the inclination of the drains. Mr. Denton has designed a still more complete apparatus for this purpose, which he names the A level, from its resemblance to that letter in form, having a cross-shifting limb, by which the inclination of one of the legs is adjusted, so that a plumb line from the apex indicates the intended fall, one of the legs having a sliding vernier, and the other having cross hairs for ranging the levels to the end of the drain, with a graduated staff.

144. In the formation of loose stone drains, after the stones are assorted as to size, and deposited in the drains, (for which purposes Mr. Roberton, of Roxburghshire, has introduced a very complete and portable form of harp or screen, provided with a moveable tailboard,) they are evenly distributed in the drain with a strong rake, and beaten down with a heavy beater, having a cross-handle for raising it. The best form of shovel for the stones is that known as the frying-pan, or lime shovel, having a raised rim around the hinder part of it, and being made of a capacious size.

145. The cutting of tile drains, requiring very exact work, is best performed with tools fitted peculiarly for it. Thus the narrow drain spade produces more perfect work in throwing out the loosened soil, and also trimming the sides of the drain, than the common spade. Pipe drains, being much narrower in the bed than any

others, are best finished with small tools designed for the purpose. These are the narrowest drain spades, made only 3 or 4 in. wide at the mouth, and having a stud or tramp in front for the heel of the workman, to assist in pressing the tool into the soil. Narrow hoes are also useful in removing small stones, &c., from the bed; and for removing any wet and loose earth that may accumulate in it since the cutting of the drain, a scoop formed like a long narrow hoe with raised sides is very effective, being, in use, drawn forward by the workman. The bed of these drains may also be very nicely finished and adjusted with a trowel, formed with the edges parallel, and rounded only near the front.

146. Bog drains are formed with some tools of peculiar form, which may be noticed. Thus the surface turf is cut along the lines of the intended drain with an edging iron of a crescent-like form, and sharpened round its outer edge. For cutting the turf out, a broadmouthed shovel is used. The moss, being cut into square peats with this shovel, is lifted from the drain with a three-pronged fork made for the purpose, or if footing be found for the workmen, the peats may be neatly cut from the bed, and thrown out with spades fitted with the handle at a large angle to the spade, which may thus be conveniently used in a horizontal position.

147. In soils where peat is plentiful, this material is sometimes cut or compressed into form, and baked so as to constitute open ducts when laid together in the drain. Mr. Calderwood, of Ayrshire, introduced, some years ago, a tool fitted to cut peats into a massive semicylindrical form by one cut, and without any waste of material, the hollow in one peat fitting the exterior of another. It is said that one man accustomed to the work can cut from 2000 to 3000 of these peats in a

day. They are afterwards dried in the sun, and stacked till required. Several highly ingenious machines have been invented for forming peat tiles, and also for moulding the pipe tiles of clay of various forms, to secure ready and accurate joints, by which improvements the cost of production has been within late years most materially reduced.

148. Some part of the work of cutting drains has, at various times, been attempted with ploughs of different forms and construction, fitted, wherever they are applicable, to effect some economy in the cost of labour for the work; but being very much limited in their opportunities of employment, and utterly inefficient unless the soil is entirely free from stones, and in the proper state of moistness, no further reference to them will be here needed.

END OF PART I.

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Chelsea Water Company's Reservoirs
Chisels for Boring

Clark's method of purifying Water

Clays, Draining of, at Folkingham, 120: in Hampshire, 119: in
Herefordshire, 120: in Kent, 118: at Newcastle on Tyne, 120:
in Norfolk, 119: at Nottingham, 120 in Scotland, 120, 124:
in Worcestershire, 120.

Formation of, Blue, Yellow, and the great Strata of Halle
Constituents of Soils

Contour Lines of Equal Altitude

Cost of Drains

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