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.