These parting Furrows, and their Ridges, must be made more or less oblique, according to the Form and Declivity of the Hill; but the more horizontal they are, the sooner the Rain-water will run off the Lands; for in that Case it will run to the Furrows, and reach them at right Angles, which it will not do when the Ridges (or Lands) are oblique; and therefore the Water’s Course cross the Lands will be longer[218]. Every one of these horizontal Trenches receives all the Water from the Rills, or little Gutters, wherein the Water runs betwixt the Mould and the Clay; these are all cut off by the Trenches, which receive the Water at their upper Sides, and carry it away, as the Trunks of Lead plac’d under the Eaves of a House do carry away the Rain-water.
[218]The natural Course of Water being downwards, it would always run by the nearest Way to the Bottom of the Hill, if nothing stopt it; but the Water runs from an Hill in Two Manners; viz. Upon the Surface of the Staple, and upon the Surface of the Clay that is under the Staple; that which runs under keeps its strait Course from the Top to the Bottom of an Hill, under a Ridge that is made exactly with the Descent of the Hill, except that Part of the Water that rises up into the Mould, and a very little that soaks into the Furrows, for when the Furrows are not made exactly with the Descent, the more oblique they are to the Descent, the longer will be the Water’s Course under the Ridges; and the shorter, as they are nearer being at Right Angles to the Descent. ’Tis also the same with the Water that falls upon the Surface of the Ridges; for the more horizontal they are, the shorter its Course will be from them to the Furrows, which carry it off; and the less of the Water will sink into the Ridges, the less oblique and the nearer to Right Angles to the Descent they are made.
If there were no other Manner of plowing Ridges on the Sides of Hills than what is commonly practised on the Plains, this Method of leaving open Furrows (or Drains on Declivities) would be impracticable; because the Plough could not turn up the Furrows against the Hill, and against the Ridge also, from the lower Side of it: But the easy Remedy against that Inconvenience is, to plow such Ridges in Pairs, without throwing any Earth into the Trenches, and then the Ridges will be plain a-top, and the Rain-water will run speedily downward to the next Trench, and thence to the Head-land, and so out of the Field. These Trenches will be made, as well as kept always open, by this plowing in Pairs; and is abundantly more easy than the Way of plowing Ridges singly. This plowing in Pairs prevents also another Inconveniency, which would otherwise happen to these horizontal Ridges; and that is, they being highest in the Middle, the Rain-water could not run freely from the upper Half of a Ridge towards the next Furrow below it, but would be apt to sink in there, and soak thro’ the Ridge; but when Ridges lie in Pairs, the Water will run off from a whole Ridge, as well as off the lower Half of a Ridge that is plow’d singly, and highest in the Middle.
Note, That every time of plowing, the Pairs must be changed, so that the Furrow, which had Two Ridges turned towards it one time, must have Two turned from it the next time: This Method keeps the Surfaces of all the Ridges (or Lands) pretty near even[219].
[219]Note, This cannot be done on an Hill, whose Declivity is so great, that the Plough is not able to turn a Furrow against it. But in this Case, perhaps, it may be sufficient to plow the Ridges obliquely enough for the Furrow to be turned both Ways.
Farmers are at more Trouble and Pains to drown such Land (it being common to break their Horses Wind in plowing up Hill) than they would be at, if they laid their Ridges in the abovesaid Manner, which would effectually make them dry. Many hundred Acres of good Ground are spoiled; and many a good Horse, in plowing against the Hill, and against all Reason, Demonstration, and Experience too; which might be learned even from the Irish, who drain their Bogs, and make them fruitful, whilst some English bestow much Labour to drown and make barren many of their Hills, which would more easily be made dry and fertile.
I have observed, that those Places of such an Hill, that, when plowed with the Descent, were the wettest, and never produced any thing that was sown on them, became the very richest, when made dry by plowing cross the Descent. This shews that Water does not impoverish Land, but the contrary; tho’, whilst it stands thereon, it prevents the Heat which is necessary to the Production of most Sorts of Vegetables: And where it runs swiftly, it carries much Earth away with it; where it runs slowly, it deposits and leaves much behind it.
Though in all Places, where this Way of making the Ridges cross the Descent of Hills is practised, the Land becomes dry; yet very few Farmers will alter their old Method[220]; no, not even to try the Experiment; but still complain their Ground is so wet and spewy, that it brings them little or no Profit; and if the Year prove moist, they are great Losers by sowing it[221].
[220]But some of late are convinced, by observing that an Hill of mine has been made dry by this means for Fourteen Years past, which before was always more wet and spewy than any Field in the Neighbourhood; and from the time of inclosing it out of an Heath (or Common), and the converting it to arable, which was about Seventy Years ago, it had been reputed as little better than barren, on account of its Wetness; and that it has been the most profitable Field of my Farm ever since it has been under this new Management. I have also another Field, that lies about a Mile and an half from me: It doth not belong to the Farm where I live, but was thrown upon my Hands, no Tenant caring to rent it, because great Part of it was full of Springs, and barren: This also, having been kept in Lands plowed cross the Descent (which is but a small Declivity), is become dry: And now the most prejudiced Farmers agree, that keeping the Lands or Ridges of wet Ground always cross the Descent doth cure its Spewiness. Hereupon some have attempted to put this Method in Practice on their wet Land; and, after it has been well tilled up Hill and down, have plowed it the last time for sowing of Wheat in flat Lands cross the Descent; but by Mismanagement their Furrows are higher at each End than the Middle, so that none of the Water can run off either downwards or sideways, or any other Way.
Had the Furrows carried off the Water at both or either of their Ends, it might have been effectual, notwithstanding the broad Lands, because their Ground hath a much less Declivity, and is much less spewy, than my Hill was: They will doubtless find their Mistake, and amend it, having a Precedent before their Eyes; but if they had none within their own Inspection, I question whether this Mismanagement might not discourage them from prosecuting their Project any further.