CHAPTER XV.
THE SOUTH DOWNS.—WILTSHIRE LANDSCAPE.—CHALK AND FLINT.—IRRIGATION.—THE COST AND PROFIT OF WATER-MEADOWS.—SEWERAGE WATER.—IRRIGATION IN OLD TIMES.
Soon after leaving Warminster, began a very different style of landscape from what I have before seen: long ranges and large groups of high hills with gentle and gracefully undulating slopes; broad and deep dells between and within them, through which flow in tortuous channels streamlets of exceedingly pure, sparkling water. These hills are bare of trees, except rarely a close body of them, covering a space of perhaps an acre, and evidently planted by man. Within the shelter of these you will sometimes see that there is a large farm-house with a small range of stables. The valleys are cultivated, but the hills in greater part are covered, without the slightest variety, except what arises from the changing contour of the ground, with short, wiry grass, standing thinly, but sufficiently close to give the appearance, at a little distance from the eye, of a smooth, velvetty, green surface. Among the first of the hills I observed, at a high elevation, long angular ramparts and earth-works, all greened over. Within them and at the summit of the hill were several extensive tumuli, evidently artificial, (though I find nothing about it in the books,) and on the top of one of these was a shepherd and dog and a large flock of sheep, clear and coldly distinct, and appearing of gigantic size against the leaden clouds behind. In the course of the day I met with many of these flocks, and nearly all the hill-land seemed given up to them. I was upon the border, in fact, of the great South-down district, and, during the next week, the greater part of the country through which we were travelling, was of the same general character of landscape, though frequently not as green, varied, and pleasing, as in these outskirts of it.
Geologically, it is a chalk district, the whole earth, high and low, and to any depth that I saw it exposed, being more or less of a white colour, generally gray, but sometimes white as snow. The only mineral is flint, which occurs in small boulders or pebbles, cased in a hardened crust of carbonate of lime mingled irregularly with the chalk, more thickly on the hill-tops, and often gathered in beds. The road is made of these flint pebbles, broken fine, and their chalk-crust, powdered by the attrition of wheels, is worked up into a slippery paste during such heavy rains as I was experiencing, and makes the walking peculiarly fatiguing. The soil upon the hills is very dry and thin. In the valleys it is deeper and richer, being composed, in a considerable part, of the wash of the higher country, and the wheat and forage crops were often very luxuriant. Advantage is sometimes taken of the streams to form water-meadows, and the effect of irrigation can often be seen at a considerable distance in the deeper green and greater density of the grass upon them. These meadows are of great agricultural value, and I will give an account of the method of construction and management of them.
An artificial channel is made, into which the water of a brook may be turned at will. This is carried along for as great a distance as practicable, so as to skirt the upper sides of fields of a convenient surface for irrigation. At suitable intervals there are gates and smaller channels, and eventually a great number of minor ducts, through which the water is distributed. The fields are divided by low walls, so that the water can be retained upon them as long as is desired, and then drawn off to a lower level. Commonly, a series of meadows, held by different farmers, are flooded from one source, and old custom or agreement fixes the date of commencing the irrigation and the period of time at which the water shall be moved from one to another.
The main flooding is usually given in October, after the grass has been closely eaten off by neat stock. It is then allowed to remain resting or quietly flowing over the land for two or three weeks; or for two weeks, and, after an interval of a day or two, for two weeks more. This consolidates the grassy surface, and encourages the growth and new formation of roots. The grass springs and grows luxuriantly after this, and, as soon as it is observed to flag, the water is let in again for two or three weeks; it may be twice during the winter. Whenever a scum is observed to form, indicating that decomposition is commencing below, the water is immediately drawn. In warm weather this will occur very soon, perhaps in a day or two. I believe the water is also never allowed, if possible, to freeze upon the meadows. In the spring, by the middle of March, sometimes sheep and lambs are turned on to the grass. After being fed pretty closely, they are removed, and the meadows left for a crop of hay. They are ready for mowing in less than two months, and are then, after a short interval, pastured again with horned cattle and horses. Some meadows are never pastured, and yield three heavy crops of hay. Mr. Pusey (a member of Parliament) declares, that he keeps sheep upon his water-meadows, in Berkshire, at the rate of thirty-six an acre, well fed, and intimates his belief that the produce of grass-land is doubled by irrigation. Grass and hay, however, from irrigated meadows, are of slightly less nourishing quality. It is generally said, that a single winter’s flooding will increase the growth of grass equal to a top-dressing of thirty (thirty bushel) loads of dung.
We may judge somewhat from these facts and opinions of practical men, whether, in any given circumstances, we can afford to construct the dam, channels, gates, sluices, &c., by which we may use this method of fertilizing our meadows. There are millions of acres in the United States that could be most readily made subject to the system. The outlay for permanent works might often be very inconsiderable, and the labour of making use of them, after construction, would be almost nothing. The cost of conveying manure, and its distribution by carts and manual labour, is a very important item in the expenditure of most of our eastern farms; and, though this is felt much less here, where labour is so much cheaper, we may obtain many economical hints with regard to it from British practice. Fields distant from the farmstead, and hill-lands not easily accessible, should nearly always be enriched by bone, guano, and other concentrated manures; of which a man may carry more on his back than will be of equal value with many cart-loads of dung, or by some other means which will dispense with long and heavy transportation. I have obtained increased crops, with a saving of some hundred dollars a-year of expenditure, in this way.
Different streams vary in their value for irrigation. The muddiest streams are the best, as they generally carry suspended a great deal of the fertile matter of the land through which they have flowed; often, too, road-washings, and other valuable drainings, have been taken along with them, and these are caused to be deposited upon the meadow. A perfectly transparent fluid will often, however, have most valuable salts in solution; and I noticed that most of the Wiltshire streams were peculiarly clear, reminding me of the White Mountain trout-brooks. It is said that streams abounding in fish, and which have abundance of aquatic plants and luxuriant vegetation upon their borders, are to be relied upon as the most enriching in their deposit. Streams, into which the sewerage of large towns is emptied, are often of the greatest value for agricultural purposes. A stream thus enriched is turned to the most important account near Edinburgh: certain lands, which were formerly barren wastes, being merely the clean, dry sands thrown up by the sea in former times, having been arranged so that they may be flowed by this stream. The expense of the operation was great—about one hundred dollars an acre—and the annual cost of flooding is very much greater than usual—four or five dollars an acre; but the crops of hay are so frequent and enormous, (ten cuttings being made in a season,) that some parts of the meadow rent for one hundred dollars a-year for one acre, and none for less than seventy-five dollars!
It is estimated by the distinguished agriculturist, Smith of Deanston, that the sewerage-water of a town may be contracted for, to be delivered, (sent by subterranean pipes and branches, so that it may be distributed over any required surface,) eleven miles out of town, for four cents a-ton. Mr. Hawksley, a prudent engineer, offers to convey it five miles, and raise it two hundred feet, for five cents a-ton; the expense of carting it to the same distance and elevation being estimated at about $1. Another estimate makes the expense of conveying and distributing manure, in the solid form, as compared with liquid, at fifteen dollars to seventy-five cents, for equal fertilizing values. Professor Johnston estimates the fertilizing value, per annum, of the sewerage of a town of one thousand inhabitants, as equal to a quantity of guano which, at present American prices, would be worth $13,000. Smith of Deanston estimates the cost of manuring an acre by sewerage, conveyed in aqueducts and distributed by jet-pipes, at three dollars an acre, and that of fertilizing it to an equal degree, in the usual way, by farm-yard manure, at fifteen dollars. Considering that the expense of conveyance and distribution of solid manure is much greater in America than in England, these figures will not be thought to be without personal interest to us.
The use of manure-drainings and the urine of the cattle of a farm, very much diluted with spring water, has been found to have such astonishing immediate effects, when distributed over young herbage, that several English agricultural pioneers are making extensive and costly permanent arrangements for its distribution, from their stables, over large surfaces. It is first collected in tanks, where it is retained until putrefied, and mixed with the water of irrigation. This is then driven by forcing-pumps into the pipes which convey it, so that it can be distributed (in one case, over one hundred and seventy acres.) The pipes are hard-burnt clay tubes, an inch thick, joined with cement, costing here about twelve and a-half cents a-yard. The pipe is laid under ground, and at convenient intervals there are heads coming to the surface with stop-cocks, where a hose can be attached and the water further guided in any direction. For greater distances, a cart like those used for sprinkling the dusty streets of our cities is used. It is conjectured by some that, eventually, all manure will be furnished to land in a state of solution.
I believe irrigation is only used for the benefit of grass-lands in England; but it probably might be found of great advantage to some other valuable crops. I have seen large fields of roots, apparently of the character of turnips, irrigated in China, and it is well known that rice is every where flooded in tropical countries. I suspect that irrigation, and even that expensive form of it that I have last described, might be profitably used, for certain plants, by our market-gardeners; I judge so of celery and asparagus; and it is well known that enormous strawberries, and unusually large and long-continuing crops of them, have resulted from an inefficient and unsystematic kind of irrigation. A small experiment that I made with Indian corn resulted in a great growth of stalk and in small and unhealthy malformed grain.
Irrigation is of the least advantage upon heavy clay soils, and of the greatest upon light sandy loams with gravelly subsoils. It is very desirable that the construction of the soil should be such that the water may gradually and somewhat rapidly filter through it; and it is considered of great importance, when the water is drawn off, after the flooding, (drowning is the local term,) that it should be very completely removed, leaving no small pools upon the surface. Stagnating water, either above or below the surface, is very poisonous to most plants.
I may remind those who have a prejudice against new practices in agriculture, that irrigation was practised as long ago as the days of the patriarchs. In this part of England it has been in use since about the beginning of the seventeenth century, at which time an agreeably-written book on the subject was published by one Rowland Vaughan, Esq. The account of the way that he was first led to make systematic trial of irrigation, and the manner in which he proceeded, is amusing and instructive:—
“In the month of March I happened to find a mole or wont’s nest raised on the brim of a brook in my meade, like a great hillock; and from it there issued a little streame of water, (drawn by the working of the mole,) down a shelving ground, one pace broad, and some twenty in length. The running of this little streame did at that time wonderfully content me, seeing it pleasing greene, and that other land on both sides was full of moss, and hide-bound for want of water. This was the first cause I undertook the drowning of grounds.
“Now to proceed to the execution of my worke: being perswaded of the excellency of the water, I examined how many foote fall the brooke yielded from my mill to the uppermost part of my grounds, being in length a measured mile. There laye of medow land thirty acres overworn with age, and heavily laden with moss, cowslips, and much other imperfect grass, betwixt my mill stream and the maine river, which (with two shillings cost) my grandfather and his grandsire, with the rest, might have drowned at their pleasures; but from the beginning never any thing was done, that either tradition or record could witness, or any other testimonie.
“Having viewed the convenientest place, which the uppermost part of my ground would afforde for placing a commanding weare or sluce, I espied divers water falls on my neighbours’ grounds, higher than mine by seven or eight foote: which gave me great advantage of drowning more ground, than I was of mine own power able to do.
“I acquainted them with my purpose; the one being a gentleman of worth and good nature, gave me leave to plant the one end of my weare on his side the river: the other, my tenant, being very aged and simple, by no perswasion I could use, would yield his consent, alleging it would marre his grounds, yea, sometimes his apple trees; and men told him, water would raise the rush, and kill his cowslips, which was the chiefest flower his daughters had to tricke the May-pole withal.
“After I had wrought thus farre, I caused my servant, a joyner, to make a levell to discover what quantity of ground I might obtaine from the entry of the water; allowing his doubling course, compassing hills to carry it plym or even, which fell out to be some three hundred acres.
“After I had plymmed it upon a true levell, I betooke myself to the favour of my tenants, friends, and neighbours, in running my maine trench, which I call my trench-royal. I call it so, because I have within the contents of my worke, counter-trenches, defending-trenches, topping-trenches, winter and summer-trenches, double and treble-trenches, a traversing-trench with a point, and an everlasting trench, with other troublesome trenches, which in a map I will more lively expresse. When the inhabitants of the country, wherein I inhabit, (namely the Golden Valley,) saw I had begun some part of my worke, they summoned a consultation against me and my man John, the leveller, saying our wits were in our hands, not in our heads; so we both, for three or four years lay levell to the whole country’s censure for such engineers as their forefathers heard not of, nor they well able to endure without merryments.
“In the running and casting of my trench-royal, though it were levelled from the beginning to the end, upon the face of the ground, yet in the bottom I did likewise levell it to avoyde error.
“For the breadth and depth, my proportion is ten foote broad, and four foote deep; unless in the beginning, to fetch the water to my drowning grounds, I ran it some half mile eight foote deep, and in some places sixteen foote broad. All the rest of the course for two miles and a-half in length, according to my former proportion. When my worke began in the eye of the country to carry a shew of profit, it pleased many out of their courtesie to give it commendations, and applaud the invention.”
The author then makes a considerable digression, to account for a delay in his proceedings, which was occasioned by processes issued against him from the courts of Star Chamber, Chancery, and Wardes, to compel him to deliver his niece and ward into their custody.
“These courts,” he observes, “bred more white haires in my head in one year than all my wet-shod water-works did in sixteen. So leaving my wanton ward in London, in the custody of a precisian or puritan taylor, who would not endure to heare one of his journeymen sweare by the cross of his shears; so full was he of sanctity in deceipt. But the first news I heard was, that he had married my Welch niece to his English nephew; and at my return, I was driven to take his word, that he was neither privy to the contract, nor the marriage.”
Mr. Vaughan next gives the following directions for carrying this plan into effect:—
“Having prepared your drowning course, be very careful that all the ground subject to the same, whether meadow, pasture, or arable, be as plain as any garden-plotte, and without furrows. Then follows your attendance in flood-times: see that you suffer not your flood water by negligence to pass away into the brooke, river, and sea, but by your sluice command it to your grounds, and continue it playing thereon so long as it appears muddy. In the beginning of March clear your ground of cold water, and keep it as dry as a child under the hands of a dainty nurse; observing generally that sandy ground will endure ten times more water than the clay. A day or two before you mow, if sufficient showers have not qualified the drought of your ground, let down your sluice into your trench-royal, that thereby you may command so much water to serve your turn as you desire. Suffer it to descend where you mean first to mow, and you shall find this manner of drowning in the morning before you mow so profitable and good, that commonly you gain ten or twelve days’ advantage in growing. For drowning before mowing, a day, or even two or three, so supplies the ground, that it doth most sweetly release the root of every particular grasse, although the sun be never so extream hot. This practice will often make good a second mowing, and in walking over grounds, I will tread as on velvet, or a Turkey carpet.”