Henry F. French

Necessity of System.—What Fall is Necessary.—American Examples.—Outlets.—Wells and Relief-Pipes.—Peep holes.—How to secure Outlets.—Gate to Exclude Back-Water.—Gratings and Screens to keep out Frogs, Snakes, Moles, &c.—Mains, Submains, and Minors, how placed.—Capacity of Pipes.—Mains of Two Tiles.—Junction of Drains.—Effect of Curves and Angles on Currents.—Branch Pipes.—Draining into Wells or Swallow Holes.—Letter from Mr. Denton.

As every act is, or should be, a part of a great plan of life, so every stake that is set, and every line laid in the field, should have relation not only to general principles, but also to some comprehensive plan of operations.

Assuming, then, that the principles advocated in this treatise are adopted as to the details, that the depth preferred is not less than four feet—that the direction preferred is up and down the slope—that the distance apart may range from fifteen to sixty feet, and more in some cases, according to the depth of drains and the nature of the soil—that no tiles smaller than one and a half inch bore will be used, and none less than two inches except for the first one hundred yards, there still remains the application of all these principles to the particular work in hand. With the hope of assisting the deliberations of the farmer on this point, some additional suggestions will be made under appropriate heads.

ARRANGEMENT MUST HAVE REFERENCE TO SYSTEM.

The absolute necessity of some regularity of plan in our work, must be manifest. Without system, we can never, in the outset, estimate the cost of our operation; we can never proportion our tiles to the quantity of water that will pass through them; we can never find the drains afterwards, or form a correct opinion of the cause of any failure that may await us.

We prefer, in general, where practicable, parallel lines for our minor drains, at right angles with the mains, because this is the simplest and most systematic arrangement; but the natural ravines or water-courses in fields, seldom run parallel with each other, or at right angles with the slope of the hills, so that regular work like this, can rarely be accomplished.

If the earth were constructed of regular slopes, or plains of uniform character, we could easily apply to it all our rules; but, broken as it is into hills and valleys, filled with stones here, with a bank of clay there, and a sand-pit close by, we are obliged to sacrifice to general convenience, often, some special abstract rule.

We prefer to run drains up and down the slope; but if the field be filled with undulations, or hills with various slopes, we may often find it expedient, for the sake of system, to vary this course.

If the question were only as to one single drain, we could adjust it so as to conform to our perfect ideal; but as each drain is, as it were, an artery in a complicated system, which must run through and affect every part of it, all must be located with reference to every other, and to the general effect.

Keeping in mind, then, the importance of some regular system that shall include the whole field of operation, the work should be laid out, with as near a conformity to established principles as circumstances will permit.

ARRANGEMENT MUST HAVE REFERENCE TO THE FALL.

In considering what fall is necessary, and what is desirable, we have seen, that although a very slight inclination may carry off water, yet a proportionably larger drain is necessary as the fall decreases, because the water runs slower.

Messrs. Shedd and Edson, of Boston, have superintended some drainage works in Milton, Mass., where, after obtaining permission to drain through the land of an adjacent owner, not interested in the operation, they could obtain but three inches fall in one hundred feet, or a half inch to the rod, for three quarters of a mile, and this only by blasting the ledges at the outlet. This fall, however, proves sufficient for perfect drainage, and by their skill, a very unhealthful swamp has been rendered fit for gardens and building-lots. In another instance, in Dorchester, Mass., Mr. Shedd informs us that in one thousand feet, they could obtain only a fall of two inches for their main, and this, by nice adjustment, he expects to make sufficient. In another instance, he has found a fall of two and a half inches in one hundred feet, in an open paved drain to be effectual.

It is certainly advisable always to divide the fall as even as possible throughout the drains, yet this will be found a difficult rule to follow. Very often we have a space of nearly level ground to pass through to our outfall; and, usually, the mains, in order that the minor drains may be carried into them from both sides, must follow up the natural valleys in the field, thus controlling, in a great measure, our choice as to the fall. We are, in fact, often compelled to use the natural fall nearly as we find it.

It is thought advisable to have the mains from three to six inches lower than the drains discharging into them, so that there may be no obstruction in the minor drains by the backing up of water, and the consequent deposition of sand or other obstructing substances. Wherever one stream flows into another, there must be more or less interruption of the course of each. If the water from the minors enters the main with a quick fall, the danger of obstruction in the minor, at least, is much lessened. A frequent cause of partial failure of drains, is their not having been laid with a regular inclination. If, instead of a gradual and uniform fall, there should be a slight rising in the bed of a drain, the descending water will be interrupted there till it accumulate so high as to be above the level of the rising. At this point, therefore, the water must have a tendency to press out of the drains, and will deposit whatever particles of sand or other earthy matter it may bring down.

Drains must, therefore, be so arranged, that in cutting them, their beds may be as nearly as possible, straight, or, at least, have a constant, if not a regular and equal fall.

ARRANGEMENT MUST HAVE REFERENCE TO THE OUTLET.

All agree that it is best to have but few general outlets. "In the whole process of draining," says an engineer of experience, "there is nothing so desirable as permanent and substantial work at the point of discharge." The outlet is the place, of all others, where obstruction is most likely to occur. Everywhere else the work is protected by the earth above it, but here it is exposed to the action of frost, to cattle, to mischievous boys, to reptiles, as well as to the obstructing deposits which are discharged from the drains themselves. In regular work, under the direction of engineers, iron pipes, with swing gratings set in masonry, are used, to protect permanently this important part of the system of drainage.

It may often be convenient to run parallel drains down a slope, bringing each out into an open ditch, or at the bottom of some bank, thus making a separate outlet for each. This practice, however, is strongly deprecated. These numerous outlets cannot be well protected without great cost; they will be forgotten, or, at least, neglected, and the work will fail.

Regarding this point, of few and well-secured outlets, as of great importance, the arrangement of all the drains must have reference to it. When drains are brought down a slope, as just suggested, let them, instead of discharging separately, be crossed, near the foot of the slope, by a sub-main running a little diagonally so as to secure sufficient fall, and so carried into a main, or discharged at a single outlet.

It may be objected, that by thus uniting the whole system, and discharging the water at one point, there may be difficulty in ascertaining by inspection, whether any of the drains are obstructed, or whether all are performing their appropriate work. There is prudence and good sense in this suggestion, and the objection may be obviated by placing wells, or "peep-holes," at proper intervals, in which the flow of the water at various points may be observed. On the subject of wells and peep-holes, the reader will find in another chapter a more particular description of their construction and usefulness.

The position of the outlet must, evidently, be at a point sufficiently low to receive all the water of the field; or, in other words, it must be the lowest point of the work. It will be fortunate, too, if the outlet can be at the same time high enough to be at all times above the back-water of the stream, or pond, or marsh, into which it empties; and high enough, too, to be protected by solid earth about it. In any case, great care should be taken to make the outlet secure and permanent. The process of thorough-drainage is expensive, and will only repay cost, upon the idea that it is permanent—that once well done, it is done forever. The tiles may be expected to operate well, for a lifetime; and the outlet, the only exposed portion of the work, should be constructed to endure as long as the rest.

It is true that this portion of the work may be reached and repaired more conveniently than the tiles themselves; but it must be remembered that the decay of the outlet obstructs the flow of the water, produces a general stagnation throughout the drains, and so may cause their permanent obstruction at various points, hard to be ascertained, and difficult to be reached. Considering our liability to neglect such things as perish by a gradual decay, as well as the many accidental injuries to which the outlet is exposed, there is no security but in a solid and permanent structure at the first.

To illustrate the importance attached to this point in England, as well as to indicate the best mode of securing the outlet, the drawings below have been taken from a pamphlet by Mr. Denton. Fig.37 represents the mode of constructing the common small outlets of field drainage.

The distinguished engineer, of whose labors we have so freely availed ourselves, remarks as follows upon the subject:

Figures 38 and 39 represent the elevation and section of larger outlets, used in more extensive works.

It is almost essential to the efficiency of drains, that there be fall enough beyond the outlet to allow of the quick flow of the water discharged. At the outlet, must be deposited whatever earth is brought down by the drains; and, in many cases, the outlet must be at a swamp or pond. If no decided fall can be obtained at the outlet, there must be care to provide and keep an open ditch or passage, so that the drainage-water may not be dammed back in the drains. It is advised, even, to follow down the bank of a stream or river, so as to obtain sufficient fall, rather than to have the outlet flooded, or back-water in the drains. Still, there may be cases where it will be impossible to have an outlet that shall be always above the level of the river or pond which may receive the drainage water. If the outlet must be so situated as to be at times overflowed, great care should be taken to excavate a place at the outlet, into which any deposits brought down by the drain, may fall. If the outlet be level with the ground beyond it, the smallest quantity of earth will operate as a dam to keep back the water. Therefore, at the outlet, in such cases, a small well of brick or stonework should be constructed, into which the water should pour. There, even if the water stand above the outlet, will be deposited the earth brought along in the drain. This well must at times, when the water is low, be cleared of its contents, and kept ready for its work.

The effect of back-water in drains cannot ordinarily be injurious, except as it raises the water higher in the land, and occasions deposits of earthy matter, and so obstructs the drains. We have in mind now, the common case of water temporarily raised, by Winter flowage or by Summer freshets.

It should be remembered that even when the outlet is under water, if there is any current in the stream into which the drain empties, there must be some current in the drain also; and even if the drain discharge into a still pond, there must be a current greater or less, as water from a level higher than the surface of the pond, presses into the drains. Generally, then, under the most unfavorable circumstances, we may expect to have some flow of water through the pipes, and rarely an utter stagnation. If, then, the tiles be carefully laid, so as to admit only well-filtered water, there can be but little deposit in the drain; and a temporary stagnation, even, will not injure them, and a trifling flow will keep them clean. Much will depend, as to the obstruction of drains, in this, and indeed in all cases, upon the internal smoothness, and upon the nice adjustment of the pipes. In case of the drainage of marshes, and other lands subject to sudden flood, a flap, or gate, is used to exclude the water of flowage, until counterbalanced by the drainage-water in the pipes.

We are quite sure that it is not in us a work of supererogation to urge upon our farmers the importance of careful attention to this matter of outlets. This is one of that class of things which will never be attended to, if left to be daily watched. We Americans have so much work to do, that we have no time to be careful and watchful. If a child fall into the fire, we take time to snatch him out. If a sheep or ox get mired in a ditch, we leave our other business, and fly to the rescue. Even if the cows break into the corn, all hands of us, men and boys and dogs, leave hoeing or haying, and drive them out. And, by the way, the frequency with which most of us have had occasion to leave important labors to drive back unruly cattle, rendered lawless by neglect of our fences, well illustrates a national characteristic. We are earnest, industrious, and intent on doing. We can look forward to accomplish any labor, however difficult, but lack the conservatism which preserves the fruit of our labors—the "old fogyism" which puts on its spectacles with most careful adjustment, after wiping the glasses for a clear sight, and at stated periods, revises its affairs to see if some screw has not worked loose. A steward on a large estate, or a corporation agent, paid for inspecting and superintending, may be relied upon to examine his drainage works, and maintain them in repair; but no farmer in this country, who labors with his own hands, has time even for this most essential duty. His policy is, to do his work now, while he is intent upon it, and not trust to future watchfulness.

We speak from personal experience in this matter of outfalls. Our first drains ran down into a swamp, and the fall was so slight, that the mains were laid as low as possible, so that at every freshet they are overflowed. We have many times, each season, been compelled to go down, with spade and hoe, and clear away the mud which has been trodden up by cattle around the outlet. Although a small river flows through the pasture, the cows find amusement, or better water, about these drains, and keep us in constant apprehension of a total obstruction of our works. We propose to relieve ourself of this care, by connecting the drains together, and building one or more reliable outlets.

GRATINGS OR SCREENS AT THE OUTLET.

There are many species of "vermin," both "creeping things" and "slimy things, that crawl with legs," which seem to imagine that drains are constructed for their especial accommodations. In dry times, it is a favorite amusement of moles and mice and snakes, to explore the devious passages thus fitted up for them, and entering at the capacious open front door, they never suspect that the spacious corridors lead to no apartments, that their accommodations, as they progress, grow "fine by degrees and beautifully less," and that these are houses with no back doors, or even convenient places for turning about for a retreat. Unlike the road to Hades, the descent to which is easy, here the ascent is inviting; though, alike in both cases, "revocare gradum, hoc opus hic labor est." They persevere upward and onward till they come, in more senses than one, to "an untimely end." Perhaps stuck fast in a small pipe tile, they die a nightmare death; or, perhaps overtaken by a shower, of the effect of which, in their ignorance of the scientific principles of drainage, they had no conception, they are drowned before they have time for deliverance from the straight in which they find themselves, and so are left, as the poet strikingly expresses it, "to lie in cold obstruction and to rot."

In cold weather, water from the drains is warmer than the open ditch, and the poor frogs, reluctant to submit to the law of Nature which requires them to seek refuge in mud and oblivious sleep, in Winter, gather round the outfalls, as they do about springs, to bask in the warmth of the running water. If the flow is small, they leap up into the pipe, and follow its course upward. In Summer, the drains furnish for them a cool and shady retreat from the mid-day sun, and they may be seen in single file by scores, at the approach of an intruding footstep, scrambling up the pipe. Dying in this way, affects these creatures, as "sighing and grief" did Falstaff, "blows them up like a bladder;" and, like Sampson, they do more mischief in their death, than in all their life together. They swell up, and stop the water entirely, or partially dam it, so that the effect of the work is impaired.

To prevent injuries from this source, there should be, at every outlet, a grating or screen of cast iron, or of copper wire, to prevent the intrusion of vermin. The screen should be movable, so that any accumulation in the pipe may be removed. An arrangement of this kind is shown in Fig.40, as used in England. We know of nothing of the kind used in this country. For ourself, we have made of coarse wire-netting, a screen, which is attached to the pipe by hinges of wire. Holes may be bored with a bit through even a hard tile, or a No. 9 wire may be twisted firmly round the end of it, and the screen thus secured.

This has thus far, been our own poor and unsatisfactory mode of protecting our drains. It is only better than none, but it is not permanent, and we hope to see some successful invention that may supply this want. So far as we have observed, no such precaution is used in this country; and in England, farmers and others who take charge of their own drainage works, often run their pipes into the mud in an open ditch, and trust the water to force its own passage.

OF WELLS AND RELIEF PIPES.

In draining large tracts of land of uniform surface, it is often convenient to have single mains, or even minors, of great length. Obstructions are liable to occur from various causes: and, moreover, there is great satisfaction in being certain that all is going right, and in watching the operation of our subterranean works. It is a common practice, and to be commended, to so construct our drains, that they may be inspected at suspicious points, and that so we may know their real condition.

For this purpose, wells, or traps, are introduced at suitable points, into which the drains discharge, and from which the water proceeds again along its course.

These are made of iron, or of stone or brick work, of any size that may be thought convenient, secured by covers that may be removed at pleasure.

Where there is danger of obstruction below the wells, relief pipes may be introduced, or the wells may overflow, and so discharge temporarily, the drainage water. These wells, sometimes called silt basins, or traps, are frequently used in road drainage, or in sewers where large deposits are made by the drainage water. The sediment is carried along and deposited in the traps, while the water flows past.

These traps are large enough for a man to enter, and are occasionally cleared of their contents.

When good stone, or common brick, are at hand, occasional wells may be easily constructed. Plank or timber might be used; and we have even seen an oil cask made to serve the purpose temporarily. In most parts of New England, solid iron castings would not be expensive.

The water of thorough-drainage is usually as pure as spring-water, and such wells may often be conveniently used as places for procuring water for both man and beast, a consideration well worth a place in arrangements so permanent as those for drainage.

The following figures represent very perfect arrangements of this kind, in actual use.

The flap attached to a chain at A, is designed to close the incoming drain, so as to keep back the water, and thus flush the drain, as it is termed, by filling it with water, and then suddenly releasing it. It is found that by this process, obstructions by sand, and by per-oxide of iron, may be brought down from the drains, when the flow is usually feeble.

SMALL WELLS, OR PEEP-HOLES.

By the significant, though not very elegant name of peep-holes, are meant openings at junctions, or other convenient points, for watching the pulsations of our subterranean arteries.

In addition to the large structures of wells and traps, such as have been represented, we need small and cheap arrangements, by which we may satisfy ourselves and our questioning friends and neighbors, that every part of our buried treasure, is steadily earning its usury. It is really gratifying to be able to allow those who "don't see how water can get into the tiles," and who inquire so distrustfully whether you "don't think that land on the hill would be just as dry without the drains," to satisfy themselves, by actually seeing, that there is a liberal flow through all the pipes, even in the now dry soil. And then, again,

and drains will get obstructed, by one or other of the various means suggested in another place. It is then convenient to be able to ascertain with certainty, and at once, the locality of the difficulty, and this may be done by means of peep-holes.

These may be formed of cast iron, or of well-burnt clay, or what is called stone-ware, of 4, 6, or 10 inches internal diameter, and long enough to reach from the bottom of the drain to the surface, or a little above it.

The drain or drains, coming into this little well, should enter a few inches above the pipe which carries off the water, so that the incoming stream may be plainly seen. A strong cover should be fitted to the top, and secured so as not to cause injury to cattle at work or feeding on the land. The arrangement will be at once seen by a sketch given on the following page.

In our own fields, we have adopted several expedients to attain this object of convenient inspection. In one case, where we have a sub-main, which receives the small drains of an acre of orchard, laid at nearly five feet depth, we sunk two 40-gallon oil casks, one upon the other, at the junction of this sub-main with another, and fitted upon the top a strong wooden cover. The objections to this contrivance are, that it is temporary; that it occupies too much room; and that it is more expensive than a well of cast iron or stone-ware of proper size.

In another part of the same field, we had a spring of excellent water, where, "from the time whereof the memory of man runneth not to the contrary," people had fancied they found better water to drink, than anywhere else. It is near a ravine, through which a main drain is located, and which is now graded up into convenient plow land.

To preserve this spring for use in the Summer time, we procured a tin-worker to make a well, of galvanized iron, five feet long and ten inches diameter, into which are conducted the drain and the spring. A friendly hand has sketched it for us very accurately; thus:

The spring is brought in at a by a few tiles laid into the bank where the water naturally bursts out. The pipe b brings in the drain, which always flows largely, and the pipe c carries away the water. The small dipper, marked d, hangs inside the well, and is used by every man, woman, and boy, who passes that way. The spring enters six inches above the drain, for convenience in catching its water to drink.

By careful observation the present Winter of 1858-9, the impression that there is some peculiar quality in this water is confirmed, for it is ascertained that it is six degrees warmer in cold weather than any other water upon the farm. The spring preserves a temperature of about 47°, while the drain running through the same well, and the other drains in the field, and the well at the house, vary from 39° to 42°.

We confess to the weakness of taking great satisfaction in sipping this water, cool in Summer and warm in Winter, and in watching the mingled streams of spring and drainage water, and listening as we pass by, to their tinkling sound, which, like the faithful watchman of the night, proclaims that "all is well."

POSITION AND SIZE OF THE MAINS.

Having fixed on the proper position of the outlet, for the whole, or any portion of our work, the next consideration is the location of the drains that shall discharge at that point. It is convenient to speak of the different drains as mains, sub-mains, and minors. By mains, are understood the principal drains, of whatever material, the office of which is, to receive and carry away water collected by other drains from the soil. By minors, are intended the small drains which receive the surplus water directly from the soil. By sub-mains, are meant such intermediate drains as are frequently in large fields, interposed across the line of the minors, to receive their discharge, and conduct their water to the mains.

They are principally used, where there is a greater length of small drains in one direction than it is thought expedient to use; or where, from the unequal surface, it is necessary to lay out subordinate systems of drains, to reach particular localities.

Whether after the outlet is located, the mains or minors should next be laid out, is not perhaps very important. The natural course would seem to be, to lay out the mains according to the surface formation of the land, through the principal hollows of the field, although we have high authority for commencing with the minors, and allowing their appropriate direction to determine the location of the mains.

This is, however, rather a question of precedence and etiquette, than of practical importance. The only safe mode of executing so important a work as drainage, is by careful surveys by persons of sufficient skill, to lay out the whole field of operations, before the ground is broken; to take all the levels; to compare all the different slopes; consider all the circumstances, and arrange the work as a systematic whole. Generally, there will be no conflict of circumstances, as to where the mains shall be located. They must be lower than the minors, because they receive their water. They must ordinarily run across the direction of the minors, either at right angles or diagonally, because otherwise they cannot receive their discharge. If, then, in general, the minors, as we assume, run down the slope, the mains must run at the foot of the slope and across it.

It will be found in practice, that all the circumstances alluded to, will combine to locate the mains across the foot of regular slopes; and whether in straight or curved lines, along through the natural valleys of the field.

In locating the mains, regard must always be had to the quantity of water and to the fall. Where a field is of regular slope, and the descent very slight, it will be necessary, in order to gain for the main the requisite fall, to run it diagonally across the bottom of the slope, thus taking into it a portion of the fall of the slope. If the fall requires to be still more increased, often the main may be deepened towards the outlet, so as to gain fall sufficient, even on level ground.

If the fall is very slight, the size of the main may be made to compensate in part for want of fall, for it will not be forgotten, that the capacity of a pipe to convey water depends much on the velocity of the current, and the velocity increases in proportion to the fall. If the fall and consequent velocity be small, the water will require a larger drain to carry it freely along. The size of the mains should be sufficient to convey, with such fall as is attainable, the greatest quantity of water that may ever be expected to reach them. Beyond this, an increase of size is rather a disadvantage than otherwise, because a small flow of water runs with more velocity when compressed in a narrow channel, than when broadly spread, and so has more power to force its way, and carry before it obstructing substances.

We have seen, in considering the size of tiles, that in laying the minor drains, their capacity to carry all the water that may reach them is not the only limit of their size. A one-inch tile might in many cases be sufficient to conduct the water; but the best drainers, after much controversy on the point, now all agree that this is a size too small for prudent use, because so small an opening is liable to be obstructed by a very slight deposit from the water, or by a slight displacement, and because the joints furnish small space for the admission of water.

Mains, however, being designed merely to carry off such water as they may receive from other drains, may in general be limited to the size sufficient to convey such water, at the greatest flow. It might seem a natural course, to proportion the capacity of the main to the capacity of the smaller drains that fall into it; and this would be the true rule, were the small drains expected to run full.

If our smallest drain, however, be of two-inch, or even one and a half inch bore, it can hardly be expected to fill at any time, unless of great length, or in some peculiarly wet place. Considering, then, what quantity of water will be likely to be conducted into the main, proportion the main not to the capacity of all the smaller drains leading into it, but to the probable maximum flow—not to what they might bring into it, but to what they will bring.

If the mains be of three-inch pipes, other things being equal, their capacity is nine times that of a one-inch pipe, and two and a quarter times the capacity of a two-inch pipe.

A three-inch main may, then, with equal fall and directness, be safely relied on to carry nine streams of water equal each to one inch diameter, or two and a quarter streams, equal to a two-inch stream. The three-inch main will, in fact, from the less amount of friction, carry much more than this proportion.

The allowance to be made for a less fall in the mains, has already been adverted to, and must not be overlooked. It is believed that the capacity of a three or four-inch pipe to convey water, is in general likely to be much under-estimated.

It is a common error, to imagine that some large stone water-course must be necessary to carry off so large a flow as will be collected by a system over a ten or twenty-acre field. Any one, however, who has watched the full flow of even a three-inch pipe, and observed the water after it has fallen into a nearly level ditch, will be aware, that what seems in the ditch a large stream, impeded as it is by a rough, uneven bottom, may pass through a three inch opening of smooth, well-jointed pipes. When we consider that a four-inch pipe is four times as capacious as a two-inch pipe, and sixteen times as large as a one-inch pipe, we may see that we may accommodate any quantity of water that may be likely anywhere to be collected by drainage, without recourse to other materials than tiles.

When one three or four-inch pipe is not sufficient to convey the water, mains may conveniently be formed of two or more tiles of any form. A main drain is sometimes formed by combining two horse-shoe tiles, with a tile sole or slate between them, to prevent slipping, as in fig. 47.

The combinations represented in the above figures, will furnish sufficient suggestions to enable any one to select or arrange such forms as may be deemed best suited to the case in hand. Where the largest obtainable tile is not large enough, two or more lines of pipes may be laid abreast.

POSITION OF THE MINOR DRAINS.

Assuming that it is desirable to run the small drains, as far as practicable, up and down the slope, the following directions, from the Cyclopedia of Agriculture, are given:

Much is said, in the English books, about "furrows," and the "direction of the furrows," in connection with the laying out of drains. Much of the land in England, especially in moist places, was formerly laid up by repeated plowings, into ridges varying in breadth from ten to twenty feet, so as to throw off, readily, the water from the surface.

These ridges were sometimes so high, that two boys in opposite furrows, between the ridges, could not see each other. In draining lands thus ridged, it is found far more easy to cut the ditches in the furrows, rather than across or upon the ridges. After thorough-drainage, in most localities, these ridges and furrows are dispensed with. The fact is, probably, only important here, as explaining the constant reference by English writers to this mode of working the land.

Whether we shall drain "down the furrows," or "across the ridges," is not likely to be inquired of, by Americans.

The accompanying diagram represents a field of about thirty acres, as drained by the owner, B. F. Nourse, Esq., of Orrington, Me., a particular description of which will be found in another place.

The curves of the ends of the minors, at their junction with the mains, will indicate their course—the minors curving always so as to more nearly coincide, in course, with the current of water in the mains.

THE JUNCTION OF DRAINS.

Much difficulty arises in practice, as to connecting, in a secure and satisfactory manner, the smaller with the larger drains. It has already been suggested, that the streams should not meet at right angles, but that a bend should be made in the smaller drain, a few feet before it enters the main, so as to introduce the water of the small drain in the direction of the current in the main. In another place, an instance is given where it was found that a quantity of water was discharged with a turn, or junction with a gentle curve, in 100 seconds, that required 140 seconds with a turn at right angles; and that while running direct, that is, without any turn, it was discharged in 90 seconds. This is given as a mere illustration of the principle, which is obvious enough. Different experiments would vary with the velocity, quantity of water, and smoothness of the pipe; but nothing is more certain, than that every change of direction impedes velocity.

Thus we see that if we had but a single drain, the necessary turns should be curved, to afford the least obstruction.

Where the drain enters into another current, there is yet a further obstruction, by the meeting of the two streams. Two equal streams, of similar velocity and size, thus meeting at right angles, would have a tendency to move off diagonally, if not confined by the pipe; and, confined as they are, must both be materially retarded in their flow. In whatever manner united, there must be much obstruction, if the main is nearly full, at the point of junction. The common mode of connecting horse-shoe tile-drains is shown thus:

Having no tiles made for the purpose, we, at first, formed the union by means of common hard bricks. Curving down the small drain toward the direction of the main, we left a space between two tiles of the main, of two or three inches, and brought down the last tile of the small drain to this opening, placing under the whole a flat stone, slate, or bricks, or a plank, to keep all firm at the bottom. Then we set bricks on edge on all sides, and covered the space at the top with one or more, as necessary, and secured carefully against sand and the like.

We have since procured branch-pipes to be made at the tile-works, such as are in use in England, and find them much more satisfactory. The branches may be made to join the mains at any angle, and it might be advisable to make this part of both drains larger than the rest, to allow room for the obstructed waters to unite peacefully.

The mains should be from three to six inches deeper than the minors. The fall from one to the other may usually be made most conveniently, by a gradual descent of three or four feet to the point of junction; but with branch-pipes, the fall may be nearly vertical, if desired, by turning the branch upward, to meet the small pipe. It will be necessary, in procuring branches for sole-tiles, to bear in mind that they are "rights and lefts," and must be selected accordingly, as the branch comes in upon the one or other side of the main.

The branch should enter the larger pipe not level with the bottom, but as high as possible, to give an inch fall to the water passing out of the branch into the main, to prevent possible obstruction at the junction.

DRAINAGE INTO WELLS, OR SWALLOW HOLES.

In various parts of our country, there are lands lying too flat for convenient drainage in the ordinary methods, or too remote from any good outlet, or perhaps enclosed by lands of others who will not consent to an outfall through their domain, where the drainage water may be discharged into wells.

In the city of Washington, on Capitol Hill, it is a common practice to drain cellars into what are termed "dry wells." The surface formation is a close red clay, of a few feet thickness, and then comes a stratum of coarse gravel; and the wells for water are sunk often as deep as sixty feet, indicating that the water-table lies very low. The heavy storms and showers fill the surface soil beyond saturation, and the water gushes out, literally, into the cellars and other low places. A dry well, sunk through the clay, conducts this water into the gravel bed, and this carries it away. This idea is often applied to land drainage. It is believed that there are immense tracts of fertile land at the West, upon limestone, where the surface might readily be relieved of surplus water, by conducting the mains into wells dug for the purpose. In some places, there are openings called "sink-holes," caused by the sinking of masses of earth, as in the neighborhood of the city of St. Louis, which would afford outlets for all the water that could be poured into them. In the Report of the Tioga County Agricultural Society for 1857, it is said in the Country Gentleman, that instances are given, where swamps were drained through the clay bottom into the underlying gravelly soil, by digging wells and filling them with stones.

In Fig.7, at page 82, is shown a "fault" in the stratification of the earth; which faults, it is said, so completely carry off water, that wells cannot be sunk so as to reach it.

Mr. Denton says that in several parts of England, advantage is taken of the natural drainage existing beneath wet clay soils, by concentrating the drains to holes, called "swallow-holes." He says this practice is open to the objection that those holes do not always absorb the water with sufficient rapidity, and so render the drainage for a time, inoperative.

These wells are liable, too, to be obstructed in their operation by their bottoms being puddled with the clay carried into them by the water, and so becoming impervious. This point would require occasional attention, and the removal of such deposits.

This principle of drainage was alluded to at the American Institute, February 14, 1859, by Professor Nash. He states, that there are large tracts of land having clay soil, with sand or gravel beneath the clay, which yet need drainage, and suggests that this may be effected by merely boring frequent holes, and filling them with pebbles, without ditches. In all such soils, if the mode suggested prove insufficient, large wells of proper depth, stoned up, or otherwise protected, might obviously serve as cheap and convenient outlets for a regular system of pipe or stone drains.

Mr. Bergen, at the same meeting, stated that such clayey soil, based on gravel, was the character of much of the land on Long Island; and we cannot doubt that on the prairies of the West, where the wells are frequently of great depth to obtain water for use, wells or swallow-holes to receive it, may often be found useful. Whenever the water-line is twenty or thirty feet below the surface, it is certain that it will require a large amount of water poured in at the surface of a well to keep it filled for any considerable length of time. The same principle that forces water into wells, that is, pressure from a higher source, will allow its passage out when admitted at the top.

We close this chapter with a letter from Mr. Denton. The extract referred to, has been here omitted, because we have already, in the chapter preceding this, given Mr. Denton's views, expressed more fully upon the same subject, with his own illustrations.

It should be stated that the letter was in reply to inquiries upon particular points, which, although disconnected, are all of interest, when touched upon by one whose opinions are so valuable.

"London, 52 Parliament Street, Westminster, S. W.

"My Dear Sir:—I have received your letter of the 17th August, and hasten to reply to it.

"I am gratified at the terms in which you speak of my roughly-written 'Essays on Land Drainage.' If you have not seen my published letter to Lord Berners, and my recent essay 'On the Advantages of a Daily Record of Rain-fall,' I should much like you to look over them, for my object in both has been to check the uniformity of treatment which too much prevails with those who are officially called upon to direct draining, and who still treat mixed soils and irregular surfaces pretty much in the same way as homogeneous clays and even surfaces, the only difference being, that the distance between the drains is increased. We have now, without doubt, arrived at that point in the practice of draining in this country, which necessitates a revision of all the principles and rules which have been called into force by the Drainage Acts, and the institution of the Drainage Commission, whose duty it is to administer those Acts, and to protect the interests of Reversioners.

"This protection is, in a great measure, performed by the intervention of 'Inspectors of Drainage,' whose subordinate duty it is to see that the improvements provisionally sanctioned are carried out according to certain implied, if not fixed, rules. This is done by measuring depth and distance, which tends to a parallel system (4 feet deep) in all soils, which was Smith of Deanston's notion, only his drains were shallower, i.e., from 2 to 3 feet deep.

"Some rules were undoubtedly necessary when the Commissioners first commenced dispensing the public money, and I do not express my objection to the absurd position to which these rules are bringing us, from any disrespect to them, nor with an idea that any better course could have been followed by the Government, in the first instance, than the adoption of the 'Parkes—Smith frequent drain system.' This system was correctly applied, and continues to be correctly applied, to absorbent and retentive soils requiring the aeration of frequent drains to counteract their retentive nature; but it is altogether misapplied when adopted in the outcropping surfaces of the free water-bearing strata, which, though equally wet, are frequently drained by a comparatively few drains, at less than half the cost.

"The only circumstance that can excuse the indiscriminate adoption of a parallel system, is the fact, that all drains do some good, and the chances of a cure being greater in proportion to the number of drains, it was not necessary to insist upon that judgment which ten years' experience should now give.

"My views on this point will perhaps be best understood by the following extract from an address I recently delivered. [Extract omitted, see p. 161].

* * * "I use one and a half inch pipes for the upper end of drains (though I prefer two-inch), one half being usually one and a half and the other half two-inch. This for minor drains; the mains run up to 9 or 10 inches, and even 18 inches in size, according to their service.

"There is no doubt sufficient capacity in one-inch pipes for minor drains; but, inasmuch as agricultural laborers are not mathematical scholars, and are apt to lay the pipes without precise junctions, it is best to have the pipes so large as to counteract that degree of carelessness which cannot be prevented. The ordinary price of pipes in this country will run thus: + meaning above, and-below, the prices named:

"The price of cutting clays 4 feet deep, will vary from 1d. to 1½d. per yard, according to density and mixture with stone; and the price of cutting in mixed soils will vary from 1½d. to 6d., according to the quantity of pick-work and rock, and with respect, also, to the price of agricultural labor. (See my tabular table of cost in Land Drainage and Drainage Systems.)

"I should have thought it would have been quite worth the while of the American Government to have had a farm of about 500 acres, drained by English hands, under an experienced engineer, as a practical sample of English work, for the study of American agriculturists, with every drain laid down on a plan, with the sizes of the pipes, and all details of soil, and prices of labor and material, set forth.

"I am, dear Sir,
"Yours very faithfully,
"The Hon. H. F. French, Exeter. "J. BAILEY DENTON."