2205. The process of boring the earth for water is now very generally practised where-over land springs are deficient. The operation consists in fixing an instrument called an auger 'to long iron rods screwed on to each other, which are turned by the action of men with a cross bar. The operation is usually begun by digging a well 6 or 8 feet deep, in the centre of which the boring instrument is placed. The nature of this instrument depends upon that of the stratum to be penetrated, and it is changed accordingly when a stratum of a different degree of hardness is arrived at. Soft clay, or loose sandy soil, is penetrated by an auger in the form of a hollow cylinder, with a longitudinal slit (a in fig. 662.), or without a slit. This auger is screwed into the rod, with a cross handle turned by the men. If the ground is very hard, a chisel (b) is screwed to the rod, and is turned round in the same manner. But to assist the action of this tool, an elastic pole (c) is connected by a chain with the borer, and made fast at one end, while a labourer keeps continually giving to the other end an up and down motion, which, corresponding to the beating motion of the men below, helps to diminish their labour. When the ground is thus perforated as far as the chisel and its rod will go, they must be withdrawn, in order to introduce a cylindrical auger (d) which has a valve within opening upwards; this, passing through the rubbish loosened by the chisel, brings it up, as it rises up through the valve, but cannot return. Sometimes an auger like that shown at e is used, consisting of a hollow cone having a spiral cutting edge winding round it. Tools of other forms are likewise employed to suit particular purposes. In order to raise the rod with the auger when required, either to change it or to take out the loose matter, a standard is made with three poles over the well, to which a tackle is fixed. The usual length of each rod is about 7 ft.; and length upon length are screwed together as the boring proceeds. The chisel is generally about 4 in. wide, and the gouge 3.25 in. Raising the rods and displacing them is effected every time the auger has to be withdrawn, which occupies a considerable time. If the borers meet with rocks, their labour is much increased, as they can get through only by repeatedly beating the tool up and down, to pulverise the rocks. When the borers arrive at the spring of water which has been expected, the hole is made smooth by passing up and down a rod for this purpose, and a pipe made of tin or other metal is forced down in lengths which are soldered together as they go down. This keeps the hole open, and prevents the admixture of water from any of the small springs in the side. Upon the whole, the boring is performed with more facility than could be imagined by those who never tried it. Borings are now made to the depth of several hundred feet, which supply a plentiful stream of water. If the original source from which the water comes be higher than the surface of the ground where the boring is made, the water will overflow; but if the source be at a lower level than the boring, then the water will not rise to the surface of the ground, and it will be necessary to dig a well to the depth to which the spring will rise; and this well serves as a reservoir to contain the water, which must be raised to the surface by a pump.' (Encyc. of Domestic Economy, p. 542.)