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which is requisite must be put into motion and action, and the surplus removed by drainage, and, if circumstances will admit, conducted to other places where it may be useful. The distribution of living water over the surface of the ground is what is termed irrigation, and in Britain it is applied and applicable only to grass lands, either for hay or for pasture, though ju warmer countries rice and some other plants which are grown for food, require to be even more copiously supplied with surface water than our irrigated grass. The removal of surplus and stagnant water is drainage ; and it may be surface drainage by open furrows or channels, under-ploughing or loosening the subsoil, or drainage, properly so called, by watercourses formed below ground, and covered up so that the surface of them may be cultivated and cropped the same as the rest of the fields in which they are situated.
The usual estimate is, that 10,000,000 of the 12,000,000 acres of arable land in England and Wales require drainage ; and in order to carry the system of irrigation as far up the hills as possible, 10,000,000 more out of the residue, and which require draining, would be added to that amount. All this could not be done in a year, or probably in a century; but it is a result which could be aimed at, and therefore it may be kept in view. Water sufficient to irrigate about 20 acres would, on a wheel 20 feet in diameter, give one horse power: and if we divide by this, the 2,000,000 acres, irrigated by the drain water of 20,000,000 acres, it would give us a power of 100,000 horse power, upon a single fall of 2} feet. But when tanks and reservoirs are used, the last, if there are more than one, should be made to answer as mill-ponds. During heavy rain, this would retain the flood water, and the substances with which it was charged, and thus conserving both the fertilizing and the mechanical power in those places where they might be most advantageously applied.
These are but approximations to accuracy; but the principles are nevertheless perfectly sound. The next point considered, is the nature of the substances by which water should be impregnated for irrigation; and also the increase of manures for cultivated land that might be obtained by preserving the sewerage and refuse of towns.
A moments reflection will convince any person that water to produce the proper effect, must hold in solution fertilizing ingredients. These consist of the fine alluvial particles brought down from the higher grounds by natural streams or artificial watercourses, and manures from any source whence they can be obtained. Now, until a good deal of thought is bestowed upon the subject of manures, as derived from animals merely, no one would readily credit how extensive and suggestive it becomes. We quote a paragraph which contains the results, of course, of careful examination :
In the case of stall-feeding, and farm-yard keep, it is estimated that each head of cattle so kept all the year round, will afford manure for an
acre ; and a horse which is much in the stable will not furnish a great deal less. There are no data from which to obtain the amount of cattle stall-fed, or kept in the farm-yard, or for the number and time at pasture in the fields; and the same want applies to the in-door and out-door keep of horses ; but if we take them altogether, adding such composts and caustic manures as are often used, together with crushed bones, bone dust, and various kinds of refuse obtained from those who use animal substances in their manufactures, there is, exclusive of the quantity that might be obtained from towns, abundance for manuring and top-dressing the whole of the arable land once in three years, which is sufficient to keep it in perfeat good heart, under the most scourging rotation : and thus, allowing the farm-yard manure to be sufficient to keep the present arable land in good heart, the refuse of the towns would be adequate to the bringing one million of acres under the plough, and treating it as liberally as the present tillage land is treated. That all the effect of every kind of manure may be turned to the production of the best crops, we should always remember that it is necessary that the land should, in the first instance, be well prepared by drainage, for, if this is not done, the benefit of all manures will be lessened, while in some cases there will be no benefit at all.
Mr. Denton having stated, on the best authorities he could find, the amount of disposible water and available power that can be obtained by a systematic conservation of the surface water, and of the amount of manure which is now lost to the country, he
goes on to explain more minutely the measure he proposes for carrying out a general plan for the improvement of land. We shall let him be heard at some length :
As to the first point, viz., the survey of the outfalls with a view to their being rendered sufficiently capacious and clear for carrying off all the surplus waters of this country, it would be presumptuous in me to offer any observations, further than that the magnitude and importance of the object demand that an engineer, or three engineers, of the highest eminence, should be the parties by whom this matter should be performed, who should act as a central and presiding board of commissioners for the whole kingdom, to direct or superintend the working of the measure by subordinate engineers, or other competent persons appointed by the several counties as county commissioners.
On the second point, viz., the organization of the main drains and reservoirs, &c., which would be carried out by the county commissioners, subject to the approval of tho central board, my observations will be few. In tropical countries, the heat is a maximum, and drainage is not wanted, because there is not generally a sufficiency of moisture for the heat to work ; and the extreme contrast to this is in countries near the Poles, where the moisture far exceeds the action of heat; while the showery climate of Britain gives it more of the latter character than it would have from its temperature only, and in very many cases this is augmented by the retentiveness of the surface sail and subsoils, which keep the water upon or near the surface.
The total remedy of this evil, or any very great improvement of the atmosphere, by any system of drainage, however scientific, however systematic and vigorously carried on, is a work of such gigantic magnitude, that no one would recommend it under any circumstance, and its accomplishment would require centuries. The drainage which I would in the mean time recommend, is on a more limited scale, and has a more immediate object, the repaying of its expense, and yielding a profit as speedily as possible, from the greater quantity and value of produce which could be brought to market.
The effect of making main drains or receivers along the principal valleys of a district, and of widening and cleansing existing watercourses, would be to influence the subordinate and private drainage of all the lands in that district, while the more immediate object of the commissioners, in setting out and appointing such receivers, would be to secure the surface water, and so prevent stagnation on the land, a national evil, the continuance of which should not depend upon individual influences. This object would be gained without interfering with, or encroaching upon, the prejudices of agriculturists, who would not be compelled to use the main receivers unless they pleased, nor would they be dictated to as to the manner in which they would perform their own works of draining, otherwise than by obliging them to follow certain directions as to the manner in which their collateral drains should enter the main receivers, so that those receivers might not be choked up, or otherwise injured. Now this point, that of intuitively leading the whole country into a general system and order of drainage, is a desideratum of such consequence, that an effort to effect it is well merited. Mr. Handley's Bill of last session, from being an optional measure (by which the smallest fraction above one-third of the proprietors could put a veto upon the desires of the greater portion of the district proposed to be drained) was very far from tending to improve the country in a national point of view; on the contrary, the effect of that measure, and indeed of any which does not include the whole country, would be to throw it into a confusion similar to that experienced at the present time in the metropolis, where the different districts, after preserving an independence of one another, have at last found the inconvenience of general disorganization.
In the arrangement of the mains and receivers of the country, great attention should be directed to a judicious concentration of the waters, for the most advantageous securing of which works of considerable magnitude would be required. The main feature and design of the system followed, should be the subsequent application of the waters.
The instances to which I am about to allude in conclusion, bear forcibly on the remaining objects of the measure I am now advocating, and for the promotion of which I am desirous of securing your parliamentary influence, viz., the conservation of surface and drainage waters, and the refuse of towns, and their applications.
There are many works in the United Kingdom affording us instances of the conservation of waters derivable from mountain and hill streams, and being analogous to the subject, clearly prove the practicability of saving and collecting the surface waters. There are the Bann reservoirs in the County Down, Ireland, which receive the streams from the Mourne mountains. Previous to their construction, the lower lands in the neighbourhood were devastated by floods at one season, while at another they had not a sufficiency of water for agricultural purposes. The mill-owners, too, were deficient for months together before these works were completed, and now they have not only a constant supply, but a superabundance, all the year round. It is so, likewise, in many places in Wales, and in considerable mill-works, the proprietors of which would otherwise be at a loss for motive
power. At Greenock, there is a striking instance of the economy of this means of collecting water when there is abundance, to provide for the time when the dryness of the season would cause a failure of the springs; in this case, the whole town is supplied with a sufficiency all the year round for the wants of its inhabitants. But, as I have taken upon myself to answer the question, "What is to be done for British agriculture ?” I refrain from adducing further and more numerous instances of the application of water for uses such as these, which are only collaterally connected with the subject.
Irrigation must take precedence of all other applications as being the most general and profitable and least expensive means of using surface waters.
The process similar to that which was adopted by the Indians is what I would recommend for the higher grounds of this country where there are no streams,
Hitherto irrigation has been adopted only on the low and flat meadows, where water could be obtained from rivers or streams, but if tanks and drainage were properly introduced, sloping pastures might be irrigated to great advantage. There is no doubt that these low and humid meadows grow by far the weightiest crops ; and it is not unusual to put ewes and lambs upon them in the spring, and afterwards obtain two or three crops of hay, whereas, if the same grounds had not been drained or irrigated, they would not have yielded one tolerable crop, but only have produced a coarse vegetation, introducing the rot among sheep.
In the reports of the commissioners on the nature and extent of the bogs in Ireland, frequent mention is made of irrigation, and a plan was recommended by Mr. Nimmo for bringing the waters of one bog, which was situated higher than another, to the lower bog, as a power of compression as well as a means of fertilization; and other scientific men, among whom were Sir H. Davy and Mr. Longfield, strongly urged upon the commission a system of this sort. But what has been done by the Duke of Portland in Clipstone Park clearly shows, that it does not necessarily follow that a meadow to be irrigated must be formed in a valley, with just sufficient fall to let the water off into the river which is to receive it. The dyke supplying the Clipstone meadows is 49 feet above the river Mauna considerable fall for a distance of only 3814 yards.
Then, as to the application of the refuse of towns, the commissioners, having discretionary power, would not take advantage of the measure by ordering the conservation of the refuse, should it appear to them that it would be detrimental to the public health ; in fact, their duty would be
as much to prevent prejudicial effects as to propose and carry out improvements. The sewerage and the irrigation of the environs of Edinburgh is a case in point, as the prosecution of the plan has been objected to, though it proves most efficiently the value of such a course of irrigation. “ Edinburgh has many advantages over most of her sister cities; the large supply of excellent spring water is one of the greatest blessings to her numerous inhabitants, both in respect to household purposes and of keeping the streets clean, as well as irrigating the extensive meadows situated below the town, by the rich stuff which it carries along in a state of semisolution, where the art of man, with the common sewer water, has made sand hillocks produce riches far superior to anything of the kind in the kingdom.
"The grass is let every year by public sale in small patches of a quarter of an acre and upwards, and generally brings from £24 to £30 per acrė per annum. In 1826, part of the Earl of Moray's meadow fetched £57 per acre per annum.
“One hundred and ten acres of Mr. Miller's meadows, in 1827, gave a clear profit of £2300.”
An instance analogous to that of Edinburgh is afforded at Crieffe.
In the parliamentary reports on the health of towns, these two cases were pointed out as the most flagrant in which public health had been sacrificed to private advantage and profit, and no doubt the objections were strong and of importance ; but it does not appear that efforts have been made to qualify the evil by chemical means, by planting round the meadows, or in fact by any of those means which a board of commissioners, composed of scientific men, would propose. We know the power of lime; but perhaps the most easy way of meeting the objection would be to direct that the refuse should be carried to a sufficient distance from the town by covered drains, into reservoirs, which might also be covered or arched over with shafts or chimneys, to expedite fermentation. This is only one of many plans which would be suggested, the moment a public body were instituted to determine the best manner of executing this truly national measure. We do not hear so much objection to the pits of Montfaucon, near Paris, where a regular commerce is maintained for the sale of manure and the manufacture of ammonia, as was raised during the inquiry into the health of towns, to the irrigation of Edinburgh.
I have one other point I would wish to state, in which the Commission would be preeminently useful, and that is, in the straightening of watercourses and rivers, and effecting of exchanges between properties, the division of which is now a tortuous boundary of the character alluded to. How many cases may be found which are incurable because the property is entailed, or under trustees, or because the land on one side belongs to a corporate body? In these cases the Commission should have summary power of executing such exchanges.
Many other advantages of vast importance might be stated as the certain result of systematic drainage, and would certainly be elicited by a parliamentary committee of inquiry into the subject. For the present, it may suffice, in conclusion, to glance at a few particulars ;-in the first place, independently of other crops, the increase in the produce of wheat VOL. II. (1842.) no. 1.