Part 18 (1/2)
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.
[Ill.u.s.tration: Figs. 41 & 42.--WELL WITH SILT BASIN, OR TRAP, AND COVER.]
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,
”The best laid schemes o' mice an' men Gang aft agley.”
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.
[Ill.u.s.tration: Figs. 43 & 44.--SMALL WELL, OR PEEP-HOLE, AND COVER.]
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:
[Ill.u.s.tration: Figs. 45 & 46.--HOW TO PRESERVE A SPRING IN A DRAINED FIELD.]
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 pa.s.ses 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 pa.s.s 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 princ.i.p.al 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 princ.i.p.ally 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 princ.i.p.al 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 circ.u.mstances, and arrange the work as a systematic whole.
Generally, there will be no conflict of circ.u.mstances, 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 a.s.sume, run down the slope, the mains must run at the foot of the slope and across it.