Farm drainage Part 21

The estimates of labor will be made at one dollar per day, in investigating this matter.

This would be the fair cash value of work by the day, perhaps; but it is far more than farmers, who have work in hand on their own farms, which may be executed in the leisure season after haying, and even into the Winter, when convenient, will really expend for such labor. Few farm operations would pay expenses, if every hour of superintendence, and every hour of labor by man and boy and beast, were set down at this high rate.

The cost of the tiles will, ordinarily, be a cash item, and the labor may be performed like that of planting, hoeing, haying, and harvesting, by such "help" hired by the mouth or day, or rendered by the family, as may be found convenient.

The cost of drainage may be considered conveniently, to borrow a clerical phrase, "under the following heads."

1. _Laying out, or Engineering._--In arranging our Spring's work, we devote time and attention to laying it out, though this hardly forms an item in the expense of the crop. Most farmers may think themselves competent to lay out their drainage-works, without paying for the scientific skill of an engineer, or even of a surveyor.

It is believed, however, that generally, it will be found true economy, to procure the aid of an experienced engineer, if convenient, to lay out the work at the outset. Certainly, in most cases, some skill in the use of levelling instruments, at least, is absolutely essential to systematic work. No man, however experienced, can, by the eye, form any safe opinion of the fall of a given tract of land. Fields which appear perfectly level to the eye, will be found frequently to give fall enough for the deepest drainage. The writer recently had occasion to note this fact on his own land.

A low wet spot had many times been looked at, as a place which should be drained, both to improve its soil, and the appearance of the land about it; but to the eye, it seemed doubtful whether it was not about as low as the stream some forty rods off, into which it must be drained. Upon testing the matter carefully with levelling instruments, it was found that from the lowest spot in this little swamp, there was a fall of seven and a half feet to the river, at its ordinary height! Again, there are cases where it will be found upon accurate surveys, that the fall is very slight, so that great care will be requisite, to lay the drains in such a way that the descent may be continuous and uniform.

Without competent skill in laying out the work, land-owners will be liable not only to errors in the fall of the drains, but to very expensive mistakes in the location of them. A very few rods of drains, more than are necessary, would cost more than any charge of a competent person for laying them out properly.

Again, experience gives great facility in judging of the underground flow of water, of the permeability of soil, of the probability of finding ledges or other rock formation, and many other particulars which might not suggest themselves to a novice in the business.

The laying out of drains is important, not only with reference to the work in hand, but to additional work to be executed in future on adjoining land, so that the whole may be eventually brought into one cheap and efficient system with the smallest effective number of drains, both minors and mains, and the fewest outlets possible; with such wells, or other facilities for inspection, as may be necessary.

In the English tables of the cost of drainage by the Drainage Companies, an estimate of $1.25 per acre is usually put down for "superintendence,"

which includes the engineering and the supervision of the whole process of opening, laying and filling, securing outfalls, and every other process till the work is completed. The general estimate of the cost of drainage is about $25.00 per acre, and this item of $1.25 is but a small per centage on that amount. The point has been dwelt upon here, more for the purpose of impressing upon land-owners, the importance of employing competent skill in the laying out of their drainage works, than because the expense thus incurred, forms any considerable item of the cost of the whole work.

2. _Excavation and Filling._ The princ.i.p.al expense of drainage is incurred in the excavation of the ditch, whether it be for tiles or for stones. The labor of excavation depends much upon the nature of the soil to be moved.

"Draining on a sound clay," says the writer of a prize essay, "free from stones, may be executed at a cheaper rate per rod, in length, than on almost any other kind of soil, as, from the firmness of the clay, the work may be done with narrow spades, and but a small quant.i.ty of soil requires to be removed. The draining of wet sands or grounds, or clays in which veins of sand abound, is more expensive than on sound clays, because a broader spade has to be used, and consequently a larger amount of soil removed; and draining stony or rocky soils is still more expensive, because the pick has to be used. This adds considerably to the expense."

Great stress is laid, by all experienced persons, upon using narrow spades, and opening ditches as narrow as possible.

It is somewhat more convenient for unskillful laborers to work in a wide ditch than in a narrow one, and although the laborers frequently protest that they cannot work so rapidly in narrow ditches, yet it is found that, in contract work, by the rod, they usually open the ditches very narrow.

Indeed, it will be found that, generally, the cost of excavation bears a pretty constant proportion to the number of cubic feet of earth thrown out.

It will surprise those unaccustomed to these estimates, to observe how rapidly the quant.i.ty excavated, increases with the increased width of the ditch.

To enable the reader accurately to compute the measurement of drains of any dimensions likely to be adopted, a table and explanations, found in the Report of the Board of Health, already quoted, are given below. The dimensions, or contents of any drain, are found by multiplying together the length, depth, and _mean_ width of the drain.

"Thus, if a drain is 300 yards long, and the cutting 3 feet deep, 20 inches wide at the top, and 4 inches wide at the bottom, the mean width would be 12 inches (or the half of the sum of 20 and 4), and if we multiply 300, the length, by 1, the depth in yards, and by 1/3, the mean width in yards, and the product would be 100 cubic yards. The following table will serve to facilitate such calculations.

_Table showing the number of Cubic Yards of Earth in each Rod (5-1/2 Yards in length), in Drains or Ditches of various Dimensions._

================================================= DEPTH. MEAN WIDTH.

-------+------+------+------+------+------+------ Inches. 7 In. 8 In. 9 In. 10 In. 11 In. 12 In.

-------+------+------+------+------+------+------ 30 0.89 1.02 1.146 1.27 1.40 1.53 33 0.98 1.12 1.26 1.40 1.54 1.68 36 1.07 1.22 1.375 1.53 1.68 1.83 39 1.16 1.324 1.49 1.655 1.82 1.986 42 1.25 1.426 1.604 1.78 1.96 2.14 45 1.34 1.53 1.72 1.91 2.10 2.29 48 1.426 1.63 1.833 2.04 2.24 2.444 51 1.515 1.73 1.95 2.164 2.38 2.60 54 1.604 1.83 2.06 2.29 2.52 2.75 57 1.69 1.935 2.18 2.42 2.66 2.90 60 1.78 2.036 2.29 2.546 2.80 3.056 =================================================

================================================= DEPTH. MEAN WIDTH.

-------+------+------+------+------+------+------ Inches. 13 In. 14 In. 15 In. 16 In. 17 In. 18 In.

-------+------+------+------+------+------+------ 30 1.655 1.78 1.91 2.04 2.164 2.29 33 1.82 1.96 2.10 2.24 2.38 2.52 36 1.986 2.14 2.29 2.244 2.60 2.75 39 2.15 2.32 2.48 2.65 2.81 2.98 42 2.32 2.495 2.674 2.85 3.03 3.21 45 2.48 2.67 2.865 3.055 3.246 3.438 48 2.65 2.85 3.056 3.26 3.46 3.667 51 2.81 3.03 3.25 3.46 3.68 3.896 54 2.98 3.20 3.44 3.666 3.895 4.125 57 3.14 3.38 3.63 3.87 4.11 4.354 60 3.31 3.564 3.82 4.074 4.33 4.584 =================================================

"Along the top of the table is placed the mean widths in inches, and on the left-hand side the depths of the drains, extending from 30 inches to 5 feet. The numbers in the body of the table express cubic yards, and decimals of a yard. In making use of the table, it is necessary first to find the mean width of the drain, from the widths at the top and bottom. Thus, if a drain 3 feet deep were 16 inches wide at the top, and 4 inches at the bottom, the mean width would be half of 16 added to 4, or 10; then, by looking in the table for the column under 10 (width), and opposite 36 (inches of depth), we find the number of cubic yards in each rod of such a drain to be 1.53, or somewhat more than one and a half. If we compare this with another drain 20 inches wide at the top, 4 inches at the bottom, and 4-1/2 feet deep, we have the mean width 12, and looking at the table under 12 and opposite 54, we find 2.75 cubic yards, or two and three-quarters to the rod. In this case, the quant.i.ty of earth to be removed is nearly twice as much as in the other, and hence, as far as regards the digging, the cost of the labor will be nearly double. But in the case of deep drains, the cost increases slightly for another reason, namely, the increased labor of lifting the earth to the surface from a greater depth."

Under the t.i.tle of the "Depth of Drains," other reasons are suggested why shallow drains are more easily wrought than deeper drains. The widths given in English treatises, and found perfectly practicable there, with proper drainage-tools, will seem to us exceedingly narrow.

Mr. Parkes gives the width of the top of a four-foot drain 18 inches, of a three-and-a-half foot drain 16 inches, and of a three-foot drain 12 inches. He gives the width of drains for tiles, three inches at bottom, and those for stones, eight inches. Of the cost of excavating a given number of cubic yards of earth from drains, it is difficult to give reliable estimates. In the writer's own field, where a pick was used to loosen the lower two feet of earth, the labor of opening and filling drains 4 feet deep, and of the mean width of 14 inches, all by hand labor, has been, in a mile of drains, being our first experiments, about one day's labor to three rods in length. The excavated earth of such a drain, measures not quite three cubic yards. (Exactly, 2.85.)

In work subsequently executed, we have opened our drains of 4 foot depth, but 20 inches at top, and 4 inches at bottom, giving a mean width of 12 inches. In one instance, in the Summer of 1858, two men opened 14 rods of such drain in one day. In six days, the same two men opened, laid, and filled 947 feet, or about 57-1/2 rods of such drain. Their labor was worth $12.00, or 21 cents per rod. The actual cost of this job was as follows:

847 two-inch tiles, at $13 per 1,000 $11.01 100 three-inch " " for main 2.50 70 bushels of tan, to protect the joints .70 Horse to haul tiles and tan .50 Labor, 12 days, at $1 12.00 ------- Total $26.71

This is 46-1/2 cents per rod, besides our own time and skill in laying out and superintending the work. The work was princ.i.p.ally done with Irish spades, and was in a sandy soil. In the same season, the same men opened, laid, and filled 70 rods of four-foot drain, of the same mean width of 12 inches, in the worst kind of clay soil, where the pick was constantly used. It cost 35 days' labor to complete the job, being 50 cents per rod for the labor alone. The least cost of the labor of draining 4 feet deep, on our own land, is thus shown to be 21 cents per rod, and the greatest cost 50 cents per rod, all the labor being by hand. One-half these amounts would have completed the drains at 3 feet depth, as has been already shown.

But the excavation here is much greater than is usual in England, Mr.

Parkes giving the mean width of a four-foot drain but 10-1/2 inches, instead of 14 or 12, as just given. Mr. Denton gives estimates of the cost, in England, of cutting and filling four-foot drains, which vary from 12 cents per rod upwards, according to the prices of labor, and other circ.u.mstances.

In New England, where labor may be fairly rated at one dollar per day, the cost of excavating and filling four-foot drains by hand labor, must vary from 20 to 50 cents per rod, according to the soil, and half those amounts for drains of three-foot depth.

Of the aid which may be derived from the use of draining plows, or of the common plow, or subsoil plow, our views may be found expressed under the appropriate heads. That drains will long continue to be opened in this vast country by hand labor, is not to be supposed, but we give our estimates of the expenses, at this first stage of our education in drainage.

3. _Cost of the Tiles._ Under the t.i.tle of "The Cost of Tiles," we have given such information as can be at present procured, touching that matter. It will be a.s.sumed, in these estimates, that no tiles of less than 1-1/2 inch bore will be used for any purpose, and for mains, usually those of three-inch bore are sufficient. The proportion of length of mains to that of minors is small, and, considering the probable reduction of prices, we will, for the present, a.s.sume $10 per 1,000 as the prices of such mixed sizes as may be used.

Add to this, the freight of them to a reasonable distance, and we have the cost of the tiles on the field. The weight of two-inch tiles is usually rated at about 3 lbs. each, though they fall short of this weight until wet.

4. _Outlets._ A small per-centage should be added to the items already noticed, for the cost of the general outfall, which should be secured with great care; although, from such examination as the writer has made in this country, and in England also, in the large majority of cases, drains are discharged with very little precaution to protect the outlets. Works completed under the charge of regular engineers, form an exception to this remark; and an item of 37 cents per acre, for iron outlets and masonry, is usually included in the estimated cost per acre of drainage.

5. _Collars._ It is not known to the author that collars have been at all used in America, except at the New York Central Park, in 1858; round pipes, upon which they are commonly used abroad, when used on any, not being yet much in use here.

In the estimates of Mr. Denton, in his tables, collars are set down at about half the cost of the mixed tiles. The bore of them being large enough to receive the end of the tile, increases the price in proportion to the increase in size. It is believed, however, that a smaller size of tiles may prudently be used with collars than without, because the collars keep the tiles perfectly in line, and freely admit water, while they exclude roots, sand, and other obstructions. A drain laid with one and a half inch tiles with collars is, no doubt, better in any soil than two-inch tiles without collars. Some compensation for the cost of collars may thus be found in the less price of the smaller tiles.

6. _Laying._ The cost of laying tiles is so trifling as hardly to be worth estimating, except to show its insignificance. The estimate, by English engineers, is two cents per rod for "pipe laying and finis.h.i.+ng."

What is included in "finis.h.i.+ng," does not appear. From the personal observations of the writer, it is believed that an active man may lay from 60 to 100 rods of tiles per day, in ditches well prepared. Indeed, we have seen our man James, lay twelve rods of two-inch tiles, in a four-foot ditch, in forty-five minutes, when he was not aware that he was working against time. This is at the rate of sixteen rods an hour, which would give just 160 rods, or a half-mile, in a day of ten hours.

7. _Number of Tiles to the Acre._ The number of tiles used depends, of course, upon the distances apart of the drains, and upon the length of the tiles used.

The following table gives the number of tiles of various length, per acre, required at different intervals:

======================================================================== Intervals between Twelve inch Thirteen inch Fourteen inch Fifteen inch the Drains, Pipe. Pipe. Pipe. Pipe.

in feet. ------------------+-----------+-------------+-------------+------------- 15 2904 2680 2489 2323 18 2420 2234 2074 1936 21 2074 1915 1778 1659 24 1815 1676 1555 1452 27 1613 1489 1383 1290 30 1452 1340 1244 1161 33 1320 1219 1131 1056 36 1210 1117 1037 968 39 1117 1031 957 893 42 1037 958 888 829 ========================================================================

The following table gives the number of rods per acre of drains at different distances:

===================================================================== Intervals between the Drains, in feet. Rods per acre.

------------------------------------------+-------------------------- 15 176 18 146-2/3 21 125-5/7 24 110 27 97-7/9 30 88 33 80 36 73-1/3 39 67-9/13 42 62-6/7 =====================================================================

It may be remarked here, that tiles, moulded of the same length, vary nearly two inches when burned, according to the severity of the heat. It may be suggested, too, that the length of the tile, in the use of any machine, is entirely at the option of the maker. It is not, perhaps, an insult to our common humanity, to suggest to buyers the propriety of measuring the length as well as calibre of tiles before purchasing. In the estimates which will be made in this detail, it will be a.s.sumed that tiles will lay one foot each, with allowance for imperfections and breakage. This is as near as possible to accuracy, according to our best observation; and, besides, there is convenience in this simple estimate of one tile to one foot, which is important in practice.

We have now the data from which we may make some tolerably safe estimates of the cost of drainage. With labor at one dollar per day, and tiles at $10 per 1,000, or one cent each, or one cent a foot, and ditches four feet deep, opened and filled at one-third of a day's labor to the rod, we may set down the princ.i.p.al items of the cost of drainage by the rod, as follows:

Cutting and filling per rod 33-1/3 cts.

Tiles 16-2/3 "

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