Farm drainage Part 37

The Albert Model Farm is one of the Government inst.i.tutions for the promotion of agriculture, by the education of young men in the science and the practice of farming; and from what was apparent, by a single day's examination of the establishment in our visit to it in August, 1857, we are satisfied of its entire success. The crops then growing were equal, if not superior, to any we have seen in any country. Much of the land covered by those crops is drained land; and having confidence that the true principles of drainage for that country must be taught and practiced at this inst.i.tution, we thought it might be instructive, as well as interesting to the farmers of America, to give them the means of comparison between the system there approved, and those others which we have described.

Had the paper been sooner received, we should have referred to it earlier in our book; yet coming as it does, after our work was mostly in type, we confess to some feeling of satisfaction, at the substantial coincidence of views entertained at the Albert Model Farm, with our own humble teachings. With many thanks to Mr. Boyle for his valuable letter, which we commend to our readers as a reliable exposition of the most approved principles of land-draining for Ireland, we give the paper entire:

ALBERT MODEL FARM, Glasnevin, Dublin, January 31, 1859.

To the Hon. HENRY F. FRENCH, Exeter, N. H.:

SIR:--Your queries on land-drainage have been too long unanswered.

I have now great pleasure in sending you, herewith, my views on the points noted. * * *

Pray excuse me for the delay in writing. I am, sir,

Your obliged and obedient servant, WILLIAM BOYLE.

LAND DRAINAGE--REPLIES TO QUERIES, ETC.

_Introductory observations._ Ireland contains close on to twenty-one millions of acres, thirteen and a half millions of which were returned as "arable land," in 1841. By "Arterial" and thorough-drainage, &c., effected through loans granted by government, the extent of arable land has been increased to fifteen and a half millions of acres. The "Board of Works" has the management of the funds granted for drainage and land improvements generally, and competent inspectors are appointed to see that the works are properly executed. The proprietor, or farmer, who obtains a loan may, if competent, claim and obtain the appointment of overseer on his own property, and thus have an opportunity of economically expending the sum which he will have to repay (princ.i.p.al and interest) by twenty-two installments. The average cost of thorough-drainage, under the Board of Works, has been about 5 per statute acre. In 1847, when government granted the first loan for land-drainage, tiles were not so easily obtained as at present, nor was tile-drainage well understood in this country; and the greater part of the drains then made--and for some years after--were either sewered with stones, formed into a conduit of various dimensions, and covered over with finely-broken stones, or the latter were filled into the bottom of the drain, to about one foot in depth, as recommended by Smith, of Deanston. The dimensions for minor drains, sewered with stones, were, usually, three and a half feet deep, fifteen inches wide at top, and three to four inches wide at bottom (distance apart being twenty-one feet); and the overseer carried about with him a wooden gauge, of a size to correspond, so that the workmen could see at a glance what they had to do. These drains are reported to have given general satisfaction; and they were cheaply made, as the stones were to be had in great abundance in almost every field. On _new_ land, trenching was sometimes carried on simultaneously with the drainage; and it very often happened that the removal of the stones thus brought to the surface, was very expensive; but they were turned to profitable account in sewering drains and building substantial fences. In almost every case the drains were made in the direction of the greatest inclination, or fall of the land; and this is the practice followed throughout the country. Some exceptions occur on _hill-sides_, where I have seen the drains laid off at an acute angle with the line of inclination. It is not necessary that I should explain the scientific reasons for draining in the direction of the fall of the land, as that point has been fully treated of, and well ill.u.s.trated, in your article already referred to. I shall now pa.s.s on to the Queries.

[Ill.u.s.tration: Thorough Drainage BY HENRY F. FRENCH. EXETER N.H.]

_Depth of drains, and distance apart._ There is still a great diversity of opinion on these points, and particularly in reference to the drainage of stiff clay soils; some of the most intelligent and practical farmers in this country hold to the opinion that, on such soils, the maximum depth should not exceed three feet, and the distance apart sixteen to twenty feet. On clay loams, having a subsoil more or less free, the general practice is, to make the drains three and a half to four feet deep, and at twenty-one to thirty feet apart. On lighter soils, having a free subsoil, four feet deep and forty feet apart are the usual limitations. This farm may be taken as a fair average of the land in Ireland, as a test for drainage; the soil is a deep clay loam; the subsoil a compact mixture of strong clay and calcareous gravel, almost free from stones. Thirty miles of drains have been made on the farm, the least distance apart being twenty-one feet, and the greatest distance thirty feet; the depth in every case, three and a half to four feet for minor drains. This drainage has given the greatest satisfaction; for although the greatest part of the work was performed by the Agricultural pupils, in training here, we have not had occasion to re-make a single drain, except in one instance, where the tiles got choked, and which I shall explain hereafter.

_Tiles: Size, Shape, Draining, Capacity, &c._ We use circular pipe tiles, of inch and a half bore, for all parallel drains whose length does not exceed one hundred yards, and two-inch pipes for any additional length up to one hundred and fifty yards, the greatest length, in my opinion, a parallel drain should reach before discharging into a main or sub-main drain. We do not find it necessary to use collars on this farm, as we have _firm_ ground to place the tiles on, and we can cut the drain to fit the tiles exactly. As regards the size of tiles for main and sub-main drains, _that_ can only be regulated by the person in charge of the drainage at any particular place, after seeing the land opened up and the minor drains discharging. As a general rule, a circular pipe of three inches internal diameter will discharge the _ordinary_ drainage of five or six statute acres, and give sufficient s.p.a.ce for the circulation of air. It should be observed, however, that this applies to a district where the annual rain-fall is from twenty-six to thirty inches, that of all Ireland being about thirty-five inches; besides, we have not the immense falls of rain in a _few hours_ that occur in other countries. All these points should be carefully considered in estimating the water-way for drainage. I have said that collars are not used with the tiles on this farm, as the bottom of the drains is quite firm and even; but, where the bed for the tile is soft, and the subsoil is of a _s.h.i.+fting_ nature, then collars should be used in every case.

Collars cost about half the price of tiles, which they are made to connect, so that the use of them adds one-third to the expense of the sewering material; and, as I have already pointed out, I think it quite unnecessary to use them where the subsoil is _firm_, and where the drain can be bottomed to _fit the tile_. Where large pipes are not to be had conveniently for sewering main or sub-drains, I find a proportional number of pipes of lesser diameter to answer perfectly. It is very desirable to provide _branch pipes_ for connecting the minor with the main drains. The branch should be socketed to receive the end of the last tile in the minor drain, and the point of attachment to the main pipe may be on the top or on the side of the latter. If the branch be made to lead the water into the side of the main pipe, then it should join the latter at an acute angle, that both streams may meet with the least possible opposition of forces.

_Fall necessary in Tile Drainage._ I consider one foot in one hundred yards the _least_ fall to work upon with safety.

_Securing Outlets._ All the outlets from main-drains should be well secured against the intrusion of vermin, by a wrought-iron grating, built in mason-work. The water may flow into a stone trough provided with an overflow-pipe, by which the quant.i.ty discharged may be ascertained at any time, so as to compare the drainage before and after rain, &c.

_Traps, or Silt Ponds._ Where extensive drainage is carried on in low-lying districts, and the princ.i.p.al outlet at a considerable distance, it may be found necessary to have traps at several points where the silt from the tiles will be kept. These traps may be of cast-iron, or mason-work, cemented; and provision should be made, by which they can be cleaned out and examined regularly--the drainage at these periods also undergoing inspection at the different traps.

_Plow-Draining._ We have no draining-plows in use in Ireland, that I know of; the common plow is sometimes used for marking off the drains, cutting the sides, and throwing out the earth to a considerable depth, thereby lessening the manual labor considerably. Efforts have been made in England to produce an efficient implement of this description; but it would appear there is ample room for an inventive Jonathan to walk in for a profitable patent in this department, and thus add another to the many valuable ones brought out in your great country.

_Case of Obstruction in Tiles._ Some years since, one of the princ.i.p.al main-drains on this farm was observed not discharging the water freely, as it hitherto had done, after a heavy fall of rain; and the land adjoining it showed unmistakable signs of wetness. The drain was opened, and traced to the point of obstruction, which was found to be convenient to a _small poplar tree_, the rootlets of which made their way into the tiles, at the depth of five and a half feet, and completely filled them, in the direction of the stream, for several yards. We have some of the tiles (horse-shoe) in our museum here, as they were then lifted from the drain, showing clearly the formidable nature of the obstruction. Another serious case of obstruction has come to my knowledge, occasioned by frogs or toads getting into the tiles of the main-drain in large numbers, on account of the outlet being insufficiently protected.

In this case, a large expenditure had to be incurred, to repair the damage done.

I have not observed any case of obstruction from the roots of our cultivated plants. It has been said by some that the rootlets of mangold will reach the drains under them; and, particularly, where the drains contain most water in rapid motion. I took up the tiles from a drain on this farm, in '54, which had been laid down (by a former occupier), about the year '44, at a depth not exceeding two-and-a-half feet, and not one of these was obstructed in the least degree, although parsnips, carrots, cabbages, mangolds, &c., had been grown on this field. Obstructions may occur through the agency of _mineral_ springs; but very few cases of this nature are met with, at least in this country. I would antic.i.p.ate this cla.s.s of obstruction, if from the nature of the land there was reason to expect it, by increasing the fall in the drains and having _traps_ more frequent, where the main outlets are at a distance to render them necessary. In my opinion, the roots of trees are the great intruders to be guarded against, and more particularly the _soft_-wooded sorts, such as poplars, willows, alders, &c. The distance of a drain from a tree ought always to be equal to the height of the latter.

_Tiles flattening in the drying process._ With this subject, I am not practically familiar. In most tile-works, the tiles, after pa.s.sing through the moulding-machine, are placed horizontally on shelves, which rise one above another to any convenient height, on which the tiles are dried by means of heated flues which traverse the sheds where the work is carried on; or they are allowed to dry without artificial heat. I prefer the tiles prepared by the latter method, as, if sufficient time be given them to be well dried, they will burn more equally, and be more durable. The tiles will flatten more or less for the first day or two on the shelves, after which they are _rolled_. This is done by boys (who are provided with pieces of wood of a diameter equal to the bore of the tile when made), who very soon learn to get over a large number daily. The "roller" should have a shouldered handle attached, the whole thickness of which should not be greater than that of the tile. The _shoulder_ is necessary to make the _ends_ of the tiles even, that there may be no _very open_ joints when they are placed in a drain.

Once rolled, the tiles are not likely to flatten again, if the operation be performed at the proper time.

As good tiles as I ever saw were dried in a different way, and not rolled at all. As they were taken from the machine--six at a time--each carrier pa.s.sed off with his tray, and placed them _on end_ carefully, upon an _even floor_. When five or six rows of tiles were thus placed, the whole length of the drying-house, a board was set on edge to keep them from falling to one side; then followed five or six other rows of tiles, and so on, till the drying-ground was filled.

This was the plan adopted in a tilery near Dublin, some years ago.

It is only a few days since I examined some of the tiles made at these works, which had been taken from a drain, where they had been in use for nine years; and the _clear ringing sound_ produced by striking them against each other, showed what little effect that length of time produced upon them, and how well they had been manufactured.

_Cost of Tiles._ We have recently paid at the works--

For 1-1/2 inch pipes 17s. 6d. per thousand.

" 2 " 25s. "

" 3 " 45s. "

Each tile one foot in length, and the one and one-half-inch pipes weighing 16 cwt. per thousand.

One of the great difficulties in connection with tile-making is, in many districts, to procure clay sufficiently free from lime. Tiles are very often sold by sample, sent a considerable distance, and it becomes necessary to test them, which we do (for lime) by placing them in water for a night; and, if lime is present in the tile, it will, of course, swell out, and break the latter, or leave it in a riddled state.

I have now endeavored to answer the queries in your postscript, and I have carefully avoided enlarging on some points in them with which your readers are already familiar. If I shall have thrown a single ray of additional light on this subject across the Atlantic, I shall be amply repaid for any attention I have given to thorough-drainage during the past twelve years.

I should here observe that I mislaid amongst my papers the portion of your letter containing the queries (it was a separate sheet), and it has not as yet turned up, so that I had to depend on a rather treacherous memory to keep the queries in my mind's eye. It is highly probable, therefore, that I have overlooked some of them.

This circ.u.mstance was the chief cause of the delay in writing.

You are quite at liberty to make any use you please of this communication.

WILLIAM BOYLE.