Irrigation was the first application of science to agriculture. Nature by it was impressed into the service of man. Her quiet and unaided processes having been noticed, they were gradually systematized to a beneficial result. And as toiling man dug and laboured at the stubborn earth to make it yield his corn, he found that bountiful nature, if rightly directed, would, through the fertilizing influence of water, produce perennial crops of grass to feed his cattle and enrich his corn land. The elements which are diffused in the air and water are concentrated in the grass. The grass feeds the cattle, and the cattle support man. In all countries in which agriculture has made progress, meadows and corn land are found conjoined. On them is developed that assimilating vegetation which gives unceasingly to the farm without receiving anything. Hence, wherever farming is understood, irrigated meadows are highly valued, and, though the art as practised in different countries varies both with the skill of the people and the necessities of the climate, it has from remote antiquity engaged much of the attention of agriculturists.

If, in our comparatively moist climate, we find our crops in some seasons diminished grievously by a continued drought, we may have some conception of the necessity under which those lie who cultivate a soil where rain seldom or never falls, to call in the aid of irrigation. With us the water of irrigation may supply either the food of the plant, or the moisture needed for its vegetation. But in Peru, Egypt, some parts of Persia, India, and China, the plant could not even strike root without the aid of water artificially applied to the parched soil.

Though the operations of irrigation and drainage seem exactly opposed to each other, they are not in reality so. The main advantage of irrigation is the deposit of nutrition to the grass from the water passing over its surface. The great use of drainage, though at first sight it appears to act merely by carrying off stagnant water, which would cool the earth and starve the plant, is to render the soil like an open filter, through which the water, as it passes off, is deprived of much of its fertilizing qualities, and these are found stored up in the porous soil, ready for the use of the roots of plants in search of food. Grass is the surface filter which retains the fertilizing qualities of the water of irrigation; the soil is the underground filter which acts in the same capacity on the water of drainage. Stagnation is equally injurious to both. The water of irrigation must pass over the surface, and that of drainage through the soil and substratum, before any benefit can arise from its presence.

According to the parliamentary return of agricultural statistics for England in 1854 (the accuracy of which under this head we feel inclined to receive with some doubt), the extent of land under irrigated meadows is 1,292,329 acres, which is equal to nearly one-half of the land under clover and artificial grass. The produce of these meadows and cultivated grasses is chiefly consumed by live stock, the manure of which goes to a considerable extent to enrich the arable corn land. Taking England and Wales alone, the proportions under corn and under cultivated grass are as 3 to 1. In France, according to Lavergne, the proportions under these crops are as 9 to 1. That is to say, while in England every three acres of corn land are enriched by the manure produced from one acre of meadow, in France the same manure has to be spread over nine acres. The result is that the average produce per acre of wheat in England is double that of France. Hence we see the importance of attention to irrigation as a means of increasing the general productions of our soil. It has indeed been asserted by M. Bousingault, the eminent French agricultural chemist, that such is the influence of irrigation that, where the system can be introduced in connection with an arable farm, the advantage accruing from it in bringing the elements of fertility on to the farm, is greater than the loss sustained by the land through the sale of its marketable produce.

The quality of the water employed exercises a great influence on the effect produced. New facts are constantly arising in proof of this.

There are four ways of irrigating land with water; and in order to preserve a command over its motions, it must in all cases enter the land to be irrigated at a higher level than where it leaves it. This disposition of materials is the only way to make water move in a sensible and equable current. 1st, One kind of irrigation is called Bed-work Irrigation, which is the most efficient, though also the most costly kind by which currents of water can be applied to level ground. 2d, Another kind is called Catch-work Irrigation, which is suited to both level and uneven ground. 3d, A third gets the name of Subterraneous Irrigation, from the water being supplied upwards to the surface through drains in the subsoil. 4th, And the fourth kind is called Warping, when the water is allowed to stand over a level field till it has deposited the mud it contains.

In addition to these a novel application of the principle of irrigation has been lately introduced into the farm practice of England, and which consists of the application, by pipes or hose, of the liquid manure of the farm, more or less diluted with water, to the growing crops, and especially to the growth of Italian rye grass. As this process is yet only in an experimental state, we can do no more than refer to it here.

Several particulars require deliberate consideration before determining on forming any kind of water meadow. The vicinity of a river is desirable, not so much on account of the supply of water, for that may be obtained in winter beside a mountain torrent or a lake, but on account of the fertilizing matter which is generally suspended in the waters of a river. Hence a river, flowing through an alluvial and cultivated country is preferable to one through a mountainous and rocky country. An ample supply of water is absolutely