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CHAPTER III.

HOW TO GO TO WORK TO LAY OUT A SYSTEM OF

DRAINS.

How to lay out the drains; where to place the outlet; where to locate the main collecting lines; how to arrange the laterals which are to take the water from the soil and deliver it at the mains; how deep to go; at what intervals; what fall to give; and what sizes of tile to use,— these are all questions of great importance to one who is about to drain land.

On the proper adjustment of these points, depend the economy and effectiveness of the work. Time and attention given to them, before commencing actual operations, will prevent waste and avoid failure. Any person of ordinary intelligence may qualify himself to lay out under-drains and to superintend their construction, but the knowl edge which is required does not come by nature. Those who have not the time for the necessary study and prac tice to make a plan for draining their land, will find it economical to employ an engineer for the purpose. In this era of railroad building, there is hardly a county in America which has not a practical surveyor, who may easily qualify himself, by a study of the principles and directions herein set forth, to lay out an economical plan for draining any ordinary agricultural land, to stake the lines, and to determine the grade of the drains, and the sizes of tile with which they should be furnished.

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On this subject Mr. Gisborne says: "If we should give a stimulus to amateur draining, we shall do a great deal "of harm. We wish we could publish a list of the moneys "which have been squandered in the last 40 years in amateur 'draining, either ineffectually or with very imperfect effi" ciency. Our own name would be inscribed in the list for a 66 very respectable sum. Every thoughtless squire suppcses "that, with the aid of his ignorant bailiff, he can effect a per"fect drainage of his estate; but there is a worse man behind "the squire and the bailiff,-the draining conjuror. *

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These fellows never go direct about their "work. If they attack a spring, they try to circumvent "it by some circuitous route. They never can learn that 66 nature shows you the weakest point, and that you should "assist her,--that hit him straight in the eye is as good a "maxim in draining as in pugilism. * * * * * * "If you wish to drain, we recommend you to take advice. "We have disposed of the quack, but there is a faculty, 66 not numerous but extending, and whose extension ap. pears to us to be indispensable to the satisfactory progress of improvements by draining,—a faculty of draining engineers. If we wanted a profession for a lad who showed any congenial talent, we would bring him "up to be a draining engineer." He then proceeds to speak of his own experience in the matter, and shows that, after more than thirty years of intelligent practice, he employed Mr. Josiah Parkes to lay out and superintend his work, and thus effected a saving, (after paying all professional charges,) of fully twelve per cent, on the cost of the draining, which was, at the same time, better executed than any that he had previously done.

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It is probable that, in nearly all amateur draining, the unnecessary frequency of the lateral drains; the extrava gant size of the pipes used; and the number of useless angles which result from an unskillful arrangement, would amount to an expense equal to ten times the cost of the

proper superintendence, to say nothing of the imperfect manner in which the work is executed. A common impression seems to prevail, that if a 2-inch pipe is good, a 3-inch pipe must be better, and that, generally, if draining is worth doing at all, it is worth overdoing; while the great importance of having perfectly fitting connections is not readily perceived. The general result is, that most of the tile-draining in this country has been too expensive for economy, and too careless for lasting efficiency.

It is proposed to give, in this chapter, as complete a description of the preliminary engineering of draining as can be concentrated within a few pages, and a hope is entertained, that it will, at least, convey an idea of the importance of giving a full measure of thought and ingenuity to the maturing of the plan, before the execution of the work is commenced. "Farming upon paper" has never been held in high repute, but draining upon paper is less a subject for objection. With a good map of the farm, showing the comparative levels of outlet, hill, dale, and plain, and the sizes and boundaries of the different inclosures, a profitable winter may be passed,-with pencil and rubber,—in deciding on a plan which will do the required work with the least possible length of drain, and which will require the least possible extra deep cutting; and in so arranging the main drains as to require the smallest possible amount of the larger and more costly pipes; or, if only a part of the farm is to be drained dur ing the coming season, in so arranging the work that it will dovetail nicely with future operations. A mistake in actual work is costly, and, (being buried under the ground,) is not easily detected, while errors in drawing upon paper are always obvious, and are remedied without cost.

For the purpose of illustrating the various processes connected with the laying out of a system of drainage, the mode of operating on a field of ten acres will be de

tailed, in connection with a series of diagrams showing the progress of the work.

A Map of the Land is first made, from a careful survey. This should be plotted to a scale of 50 or 100 feet to the inch,* and should exhibit the location of obsta cles which may interfere with the regularity of th drains, such as large trees, rocks, etc., and the existing swamps, water courses, springs, and open drains. (Fig. 4.)

The next step is to locate the contour lines of the land, or the lines of equal elevation,-also called the horizontal lines,—which serve to show the shape of the surface. To do this, stake off the field into squares of 50 feet, by first running a base line through the center of the greatest length of the field, marking it with stakes at intervals of 50 feet, then stake other lines, also at intervals of 50 feet, perpendicular to the base line, and then note the position of the stakes on the maps; next, by the aid of an engineer's level and staff, ascer tain the height, (above an imaginary plain below the lowest part of the field,) of the surface of the ground at each stake, and note this elevation at its proper point on the map. This gives a plot like Fig. 5. The best instrument with which to take these levels, is the ordinary telescope-level used by rail. road engineers, shown in Fig. 6, which has a telescope with cross hairs intersecting each other in the center of the line of sight, and a "bubble" placed exactly parallel to this ine. The instrument, fixed on a tripod, and so adjusted that it will turn to any point of the compass without disturbing the position of the bubble, will, (as will its "line of sight,") revolve in a perfectly horizontal plane. It is so placed as to command a view of a considerable stretch of the field, and its height above the imaginary plane is measured, an attendant places next to one of the stakes a levelling rod, (Fig. 7,) which is divided into feet and

*The maps in this book are, for convenience, drawn to a scale of 10 feet to the inch.

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Fig. 4. MAP OF LAND, WITH SWAMPS, ROCKS, SPRINGS, AND TREES. INTENDED TO REPRESENT A FIELD OF TEN ACRES BEFORE ? DRAINING.

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