Why they did not improve the Plough, so that it might also till as well as the Spade, seems owing to their Primitive Theory, which gave no Mathematical Reason to shew wherein the true Method of Tillage did consist; viz. in dividing the Earth into many Parts, to increase its internal Superficies, which is the Pasture of Plants.
The Difference betwixt the Operation of the Spade, and that of the common Plough, is only this; that the former commonly divides the Soil into smaller Pieces, and goes deeper.
How easy and natural it is to contrive a Plough that may equal the Spade, if not exceed it, in going deeper, and cutting the Soil into smaller Pieces, than the Spade commonly does, I leave to the Judgment of those who have seen the Four-coulter’d Plough.
The Plough describ’d by Virgil had no Coulter; neither do I remember to have seen any Coulter in Italy, or the South of France; and, as I have been informed, the Ploughs in Greece, and all the East, are of much the same Fashion: Neither is it practicable to use a Coulter in such a Plough; because the Share does not cut the Bottom of the Furrow horizontally, but obliquely; in going one way, it turns off the Furrow to the right Hand; but in coming back, it turns it to the Left[256]. Therefore, if it had a Coulter, it must have been on the wrong Side every other Furrow: And besides, as the Handle (for it has but one) always holds the Plough towards one Side, with the Bottom of the Share towards the unplow’d Land, it would cause the Coulter to go much too low when it went on the Furrow-side, and it would not touch the Ground, when it went on the Land-side.
[256]Note, This Eastern Plough always goes forward, and returns back in the same Furrow, making only one Land of a whole Field: Though it turns its one Furrow towards the Right, and the other towards the Left of the Holder; yet every Furrow is turned towards the same Point of the Compass, as when we plow with a Turn-wrist Plough.
’Tis a great Mistake in those who say Virgil’s Plough had Two Earth-boards; for it had none at all; but the Share itself always going obliquely, served instead of an Earth-board; and the Two Ears, which were the Corners of a Piece of Wood lying under the Share, did the Office of Ground-wrests: This Fashion continues to this Day in those Countries, and in Languedoc.
This sort of Plough performs tolerably when Ground is fine, and makes a shift to break up light Land; and I could never find any other Land there; I am sure none comparable to ours for Strength: And it would be next to impossible, to break up such as we in England call strong Land with it.
I do not find, that the Arable Lands about Rome are ever suffered to lie still long enough to come to a Turf; but I have observed in the low rich Lands in the Calabria’s, subject to the Invasions of the Turks, that there is Turf, and that these Ploughs go over the Land Two or Three times before the Turf of it is all broken, tho’ the Soil be a very mellow Sort of Garden-mould. Having no Coulters to cut it, they break and tear Turf into little Pieces. This was done in the Month of November; and had I not seen Men and Oxen at the Work, or had there been Oaks in the Place, I should rather have thought that Tillage performed by a Race of the first Teachers of it, in muzzling Acorns, than by Ploughs. However, the Mould being naturally very mellow, when the Turf is broken with shallow Plowing, they can plow deeper afterwards.
The English Ploughs are very different from the Eastern, as in general the Soil is.
These, when well made, cut off the Furrow at the Bottom horizontally; and therefore, it being as thick on the Land-side as on the Furrow-side, the Plough cannot break it off from the whole Land, at such a Thickness (being Six times greater than the Eastern Ploughs have to break off), and must of Necessity have a Coulter to cut it off: By this means the Furrow is turned perfectly whole, and no Part of the Turf of it broken; and if it lie long without new turning, the Grass from the Edges will spread, and form a new Turf (or Swerd) on the other Side, which was the Bottom of the Furrow before turning, but is now become the Surface of the Earth, and may soon become greener with Grass than before Plowing; and often the very Roots send up new Heads to help to stock the reversed Furrow, the former Heads being converted into Roots, so that it is doubly cloathed and braced on both Sides, or, as it were, kay’d together, firm and solid, almost as a Plank; it may be drawn from one Side of a Field to the other without breaking, and might possibly be made use of, instead of Virgil’s Crates Viminea, for harrowing or smoothing of fine-tilled Ground; but not without much Time, Labour, and Difficulty, can it be made such itself.