Part 48

What I mean by gaining of Ground, is the increasing of the Earth’s Surface: For if a flat Piece be plow’d up into Ridges, and if in each Sixteen Feet Breadth there be an empty Furrow of Two Feet; and yet, by the Height and Roundness of the Ridges, they have Eighteen Feet of Surface capable of producing Corn, equally to Eighteen Feet whilst the Piece was flat; there will be one Eighth Part of profitable Ground or Surface gain’d, more than it had when level; and this, I believe, Experience will prove, if the thing were well examined into.

But against this Increase of profitable Ground, there is an Objection, which I must not call a frivolous one, in respect to the Authors who bring it; yet, I hope, the Desire of finding the Truth will justify me to examine it; and the Arguments brought to sustain it.

This Opinion of theirs is founded upon their Notion (which I think very erroneous) of the perpendicular Growth of Vegetables; and is, by Mr. Bradley, set in its best Light, in his Vol. I. Pag. 8. usque ad Pag. 13. and in his Cuts, representing Three Hills; but his Arguments seem to be such as all Arguments are, which pretend to prove a thing to be what it is not; viz. Sophistical ones.

The Hypothesis he endeavours to prove, is in Pag. 8. thus: ‘An Hill may contain Four equal Sides, which meet in a Point at the Top; but the Contents of these Four Sides can produce no more, either of Grain or Trees, than the plain Ground, upon which the Hill stands, or has at its Base: and yet, by the Measure of the Sides, we find twice the Number of Acres, Roods, and Poles, which measure in the Base, or Ground-plat; and therefore Page 9. Hills are worth no more than half their Superficial Measure; i. e. Two Acres upon the Side of the Hill to pay as much as one upon the Plain, provided the Soil of both is equally rich.’

To prove it, he gives an Example in Fig. III. of Buildings upon an Hill; shewing, that the Two Sides of the Hill will only bear the same Number of Houses, that may stand in the Line at the Base.

This is foreign to the Question, of how much Grain, or how many Trees, the Hill will produce. For Vegetables, being fed by the Earth, require much more of its Surface to nourish them, than is necessary for them to stand on; but Buildings require no more of the Surface but Room to stand on: Therefore no such Argument, taken from Buildings, can be applied to Vegetables.

This Argument of Mr. Bradley’s gives no more Satisfaction to the Question about producing of Vegetables, than a Grazier would do, being asked, how many Oxen a certain Pasture-ground would maintain, if he should answer, by satisfying you with the Number of Churches which might stand thereon.

The like Answer, in effect, may be given to the Argument in Fig. IV. of the Pales; only he has forgot to shew, that to mound over the Hill would require double the Rails, or double the Hedge-wood (except Stakes) as to mound the Base; if it did not, the Hill would be yet of the more Value, because thereon more Surface might be fenced in at less Expence.

In his Fig. II. he gives no good Reason why the Hill should not bear twice the Number of Trees as the Base can do; for there is as much Room for Two hundred Trees on the Hill, as for One hundred on the Base, because he allows the Surface to be double to that of the Base. He ought to measure the Distances of the Trees on the Hill, by a Line parallel to the Surface they grow on, as well as he does the Distances of those below.

And suppose the Row at the Base, together with the Surface they grow on, were rais’d up, so that it should become parallel to half the Row on the Hill, would not the Trees in the Base Row be twice as near to one another as the Trees in the Hill Row are? And suppose a Line had been ty’d from the Tops of all the lower Trees, before the Row was so rais’d up at one End, and then, after the Situation of the Row was so alter’d, if by this Line the Trees should be pull’d from being perpendicular to the Surface they grow on, and made to stand oblique to that, and perpendicular to the Horizon, as the upper Trees are; would the Distances of the Trees from one another be alter’d by this Change of Posture? No, for their Bottoms would be at the same Distances, because not removed; and their Tops, because the same Line holds them, at the same Distances in both Postures.

Mr. Bradley’s Lines, drawn from the Trees below, which are one Perch asunder, make the Two Rows of Trees falsly seem to be at equal Distances, because these Lines are parallel to each other: But this is a Deceit; for, in Truth, the Distances of the Trees are not measured by the Distances of those Lines, but by the extreme Points at the Ends of the Lines; and those Two Points above, where the Lines cut the Row obliquely, and at unequal Angles are twice as far asunder as the endmost or extreme Points below are, where the Lines cut the Row at right Angles. Hence may be inferr’d, that there is Room for twice as many Trees to grow on the Hill as on the Base, and twice as much Grain for the same Reason; because there is twice the Surface for the Roots to spread in. And since Mr. Bradley allows the Hill to contain Two Perches to One of the Base, and the Soil of both to be of equal Goodness; and yet affirms, that the Two can produce no more of Grain or Trees than the one Perch can; I cannot see, why it should not be as reasonable to say, that Two Quarters of Oats will maintain an Horse no longer, nor better, than One Quarter of Oats, of equal Goodness, will do.

These upper Trees are measured by the unequal Length of the Lines, not by their parallel Distance, as the lower Trees are; therefore his Measure is a Quibble.

In Page 13. he concludes thus: ‘That Hills, in their Measure, contain only as much profitable Land as the Plain or Plat of Ground they stand upon; and as a Proof of that, all Vegetables or Plants have an erect Method of Growth.’

This Proof of Mr. Bradley’s is founded upon an Argument which has no Consequence, unless it were first proved, that the Surface of Earth could produce and maintain as many Vegetables or Plants as could stand thereon in an erect Posture; which Supposition is as impossible, as that half an Acre should produce and maintain an Hecatomb, without Mr. Bradley’s teaching Oxen to live upon Air for their Food, as he thinks Van Helmont’s Tree did.

All expert Husbandmen must needs be convinced, that the greatest Crop of Vegetables that ever grew, might stand in an erect Posture, upon a twentieth (and I may say the Hundredth) Part of the Surface that produced it; therefore there must be Nineteen Parts for the Roots to spread, unoccupied by the Trunks, Stems, or Stalks.

And tho’ it be true, that an Hill will support no more of these, than its Base, when placed in an erect Posture, close together, as in a Sheaf; yet this close Position is only proper for them when they are dead, and require no more Nourishment than Houses and Pales do; and consequently require no Room but to stand on. Therefore this Argument of Mr. Bradley’s must not be admitted in vegetative Growth, where there is always required Nineteen times more Room in the Surface, for the Use of the Roots, than what the Stems, Trunks, or Stalks, do possess upon it: And the more Room there is for the Roots, the greater Number of Plants may be produced.

Neither can I admit, that all Vegetables or Plants have an erect Method of Growth; because the contrary is seen in Chamomile, and divers other Vegetables, which have an horizontal Method of Growth.

But what is more material to this Purpose, to be observed, is, that all Vegetables have horizontal Roots, and Roots parallel to the Earth’s Surface or Superficies; and unless those Roots have a sufficient Superficies of Earth to range in, for Nourishment of a Plant, the Stem and Branches cannot prosper, whatever be their Method of Growth above the Earth; and if there be not a due Quantity of Food for the Roots within the Earth, a very little Space may contain the external Parts of Vegetables upon it.

From what has been said, I think we may conclude, that Mr. Bradley’s Hill may produce more Vegetables than the Base whereon it stands; and therefore it is of more Value than half its superficial Measure; i. e. Two Acres on the Hill are worth more than one Acre on the Plain, the Soil being equally rich, as he allows it to be, in his Case.

Now, indeed, whether Mr. Bradley might not possibly be deceived in his Opinion of the equal Richness of his Hill, and his Plain, I will not dispute: I will only say this, that ’tis generally otherwise. But where a Plain is plow’d up into moderate Ridges, their Height being in proportion to the Depth of the Staple, below which the Plough must take nothing into the Ridges, the Soil is equally rich, whether it be plowed plain, or ridged up. And as the Surface is in the Ridges increased, there is nothing in all Mr. Bradley’s Arguments, that shews, why that increased Surface should not produce more Vegetables than the same Earth could do whilst it was level.

There are other Reasons why it should produce more when ridged, besides the Increase of Surface; as,

I. ’Tis then more free from the Injuries of too much Water.

II. ’Tis better protected against cold Winds; because the Ridges are a Shelter to one another.

III. If the Surface be much exhausted, by too frequent Sowing, the Ridges may be made just where the Furrows were, and then the Surface will be intirely changed.

To the Three we may add a Fourth Reason, viz. the raising the Thickness of the Staple in the Ridges, keeping the Surface drier in wet Weather, and moister at the Bottom of the Staple in dry Weather. And I have seen Barley that was drilled on my raised little Ridges flourish in a dry Summer on the Brow of my chalky Hill, and on my lowest Land in wet Weather, when the Barley hand-sown contiguous to it on each Side those Ridges, sown on the Level the same Day that the Ridges were drilled, have looked yellow and sickly; and yet it is not wet Land.

The following general Rules ought to be observed about Ridges; viz.

That, as to their Height, regard must be had to the Nature of the Soil, in its difficult Admission of Water; for the greater that is, the greater Declivities the Ridges should have; and then, if the Soil be not deep, they should generally be made the narrower.

There is one thing which Mr. Bradley takes no notice of; viz. That no more of the Rain, or other Benefits of the Atmosphere, which descend perpendicularly, can fall on an Hill, or on a Ridge, than what would fall on the Base, or Ground-plot. But ’tis probable, that more of the fine Vapour, which swims in the Current of the Air horizontally, does strike and break against those Eminences, and so make an Equivalent, except that it runs off more quickly.