Part 4

Now first, for making the bank or head, you must be sure it is tight, and that it do not sew or leak, as it will certainly do, if it be composed of mere earth; therefore a bed or wall of clay, the whole length of the bank, must be carried up with good ramming, from a foot or two below the surface of the ground, to such height as you propose the water shall stand.

If you do not give the bed of clay this foundation, the water lying under a great weight from the depth of it, will work itself underneath, so allow a spit or two at least for it. Then, as you ram the clay, you must be sure that earth be brought to carry the bank up with it, or else the sun will search and crack it, which is of pernicious consequence; so when it is come to its full height, close and cover it with earth immediately, lest the inconvenience happens.

You must allow three feet to the breadth of this bed of clay, and raise it to the height you intend the water shall stand, and lay earth three feet higher; two feet would have served, but that the allowance of one at least must be made for the sinking of the bank; for it will do so notwithstanding the pressing of tumbrels, horses, and men working upon it.

If you project many stews, or other ponds to be sunk right down about the same time, you will have great advantage by the clay you take out of them, which will be much more than is necessary for the bed, and that may fortify the bed, by being pressed down by the tumbrels on each side of it; and so the bank will be very much confirmed, and it will also save breaking of ground within the pond, which is a great advantage in the feed of the fish.

The Dimensions of Pond-Heads.

The dimensions of these banks are governed by the manner of the hills rising; for if it be quick, then, to cover a competent quantity of ground, you must raise the bank higher, and consequently it must be made stronger, than when the ground riseth slow, so as a moderate height shall cast the water upon ground enough. And of this there will be great difference; for in some places, ten feet high shall cover as much as twenty feet in others. And this will be easily discovered by the water-level, used according to art, whereby you may stake the water-line upon the ground to any height; and so you will fix the determinate height of the bank.

I will suppose a medium, and that a bank, fourteen feet high at the center, will cover the quantity of ground. Then you must make your bank at the foot at least fifty feet wide, and so straitening by equal degrees on either side, bring it to sixteen at the top; and so you will have a sufficient slope, and the bank will stand firm and durable, scarce to be destroyed without as much pains and industry as made it.

By this proportion, pond heads of any dimension may be projected; the matter is not so nicely circumstanced, that a little more or less should signify. But it must be noted, that to make them too slight, is the greatest error, and most to be avoided; let them be rather made too strong, for then you have not only a more secure bank, but a more beautiful walk, and more room for wheel-carriage, besides a capacity of some wood; all which compensate the charge of what is superfluous.

Of securing your Banks.

If the bank be well made, and in sufficient dimension, nothing can hurt it, but great land-floods, or water-shots, which, if suffered to run over the bank, will carry away the fish, which in a warm flood will rise, and go with it to seek adventures, but also gurry holes in the back of the bank, and weaken it so much, that if the flood continues, it shall carry all away together.

For preventing of this mischief, there are two ways; 1. Grates at each end of the bank, planted upon the level that is to be the highest of the water. 2. Channels of diversion, which being taken so high in the current as may lead the water upon the side of either hill above the bank, you have the power to turn out all the water when you please, so that none shall come upon the bank.

1. As to grates, the way of them is well known; however observe, that if they be made of wood, the banks must be set diagonally, like window-bars; for so rubbish stops least against them, and the water passeth freely. And in regard you cannot allow any great distance between them for keeping in the fish, you must help out the room by extending the grate from each side of the cut in the bank where the water is to vent, some considerable space from the bank, and there to meet in a point, forming a triangle upon the bank. Here are many more slits for the water to vent at, than if the grate lay flat upon the bank, covering the passage only. And if need be, there may be doors to slide up and down, made in the grate, to let the water pass more freely; but this endangereth losing the fish. If you will afford iron for these grates, you need only cover the passage of the bank; for the bars need not be so thick, but there will be space enough for the water to vent at.

2. The channels for diverting the water are very useful in this and many other respects; for they give you a perfect command of the water, and you may turn it which way you please, so as to fill or keep dry any of the ponds, and in a wet season are a perfect security. These should be made four feet wide, and on each side of the ponds the loss of ground is not considerable; for wood growing there will make amends for it.

The string of ponds in Hyde-Park are admirably disposed in this respect; for the current of the valley is carried along by the side of all the ponds, and may be let into any of them, or any may be emptied into it; than which, there is not a greater command of water.

However carefully a bank is made, it is probable it will sew a little at first; but this should be no discouragement; for by the settling of the earth, it will continually grow higher, and in a few years, if made with tolerable care, be as firm as a rock.

Of Sluices.

These are very requisite to the good command of a water, and though very ordinarily used, yet require an experienced carpenter to make and fix them as should be, especially in great waters; and such as have not experience, shall err most grossly in this work. They must be framed so as to stand firm, that the force of any thrust, or a boat’s running against them, may do no prejudice to them: for if they are any thing strained, they are apt to prove leaky; and in so great an height as is needful for deep waters, a small matter will do it, unless they are extraordinarily well abutted.

The timber-work must be heart of oak, especially the top, and that all of one piece, how long soever it be; and the vent hole must be guarded with large boxes perforated so as the water, but no fish, may pass. And all this well framed, and what is under ground extraordinarily rammed with clay, else it will be apt to leak.

The use of these is very great: for if a great water must be emptied, you must either apply engines, cut the bank, or draw a sluice. As for engines, they are too chargeable, and puzzling to fix; however, I may propose to them that are lovers of art, some facile ways of lifting great quantities of water. Then, if you cut the bank, the passage is interrupted and made troublesome by the earth, and you shall scarce ram it up so well again, but it will perpetually leak about the place where the fissure was; but sluices vent the water certainly, though slowly, without any labour, charge, or inconvenience.

Of the Manner of working to raise a Pond-Head.

Now, as for the manner of raising this bank, which I think is the only chargeable work you have, I shall give some light into the way of working, so as to abridge the expence as much as may be. The advantage of trades, is, that by continual experience, they find nearer ways of doing things, spending fewer strokes, and less time, than others can. And in the conduct of this work, there is much to be saved; every man’s reason leads him to contrive compendiums of business, as I have done in the disposition of my waters; which experience of mine may save others the thought, as well as loss by making their own experiments.

When you have projected your work, for which the latter end of June, or the beginning of May, is the best time, take the assistance of your neighbours, and provide yourself with six tumbrels, four good horses, and two stout labourers, besides the driver to each pair of tumbrels. I call them pairs, because they work alternately with the same horses; so that one is filling, while the other is moving, and your labourers, as well as horses, are always at work.

The first work to be done, is, the taking up the first spit of earth where the bank is to be, and from the pan of the pond, and to lay it by for the uses I shall declare hereafter.

Then lay down your sluice, with trunks sufficient to convey the water through the head or bank. This must be done at the deepest part of the ground, which probably will fall in the center of the bank. This will employ two pair of tumbrels and four labourers, for digging and fetching of clay, besides four labourers to ram it, which must be, as was said, very well done. And the carpenter, who beforehand hath fitted his work, must attend also one whole day to help in the laying it down, and to see it well rammed.

The next day’s work may be the employment of two pair of tumbrels in fetching of clay, and four or five good labourers to ram the foundation of the bed of clay. And I suppose this may rise a foot in one whole day’s work, more or less, as the length of the head is. Clay riseth stiff, and for that, if it riseth near, as in the pan of the pond, three labourers to a pair of tumbrels, are requisite to dig and fill, otherwise the horses will be idle, and want work as well as the rammers.

The day after employ four pair of tumbrels more, to fetch earth out of the pan of the pond to lay along the bank on each side of the bed of clay, the whole length of the head; and to this work, two labourers for a pair of tumbrels are enough.

Here you must lay on six labourers at least, to ram the bed of clay, and spread earth upon the bank, so that it may be done as fast as the six tumbrels supply it; and by this means the bank and bed of clay will rise together.

Thus you proceed till the bank is finished, which will rise faster as you come nearer the top, and so will somewhat alter the employment of the tumbrels and men, which you must conform in proportion accordingly. And observing these directions, you may make two ponds in one month (supposing the weather propitious), which shall be three, four, or five acres apiece, as the ground gives, and not expend in money above eighty pounds, although you pay for every hour’s work of man and horse.