_Resp._ The Furrow, being cut into Four Parts, has not only Four times the Superficies on the Eight Sides which it would have had on Two Sides; but it is also more divided cross-ways; _viz._ The Ground-wrest presses and breaks the lower (or Right-hand) Quarter; the other Three Quarters, in rising and coming over the Earth-board, must make a crooked Line about a Fourth longer than the strait one they made before moved; therefore their Thinness not being able to hold them together, they are broken into many more Pieces, for want of Tenacity to extend to a longer Line, contrary to a whole Furrow, whose great Breadth enables it to stretch and extend from a shorter to a longer Line, without breaking; and, as it is turned off, the Parts are drawn together again by the Spring of the Turf or Swerd[258], and so remain whole after Plowing. Thus the Four-coultered Plow can divide the Soil into above Twenty times more Parts than the common Plough; and sometimes, when the Earth is of a right Temper betwixt wet and dry, the Earth-board, in turning the Furrows off, will break them into Dust, having more Superficies than is made by Four common Plowings; and it is impossible there should be any large Pieces amongst it. [258] A swerdy Furrow cut off by only one Coulter, being whole, is apt to stand up on its Edge, or lie hollow; and then, being open to the Air, it does not rot; but when it is cut by several Coulters, it has not Strength to support itself, it falls down, lies close to the Earth under it, and, excluding the free Air from the Turf, it soon becomes rotten. And for killing the Turf of swerdy Land is the chief Use of the Four-coultered Plough: For doing of which there is this Advantage, that as in a whole Furrow there are often Strings of Couch-grass, Three or Four Feet long; but, when cut by this Plough, there is scarce a String left of one Foot long: And these Strings being apt to send out Roots from every Knot or Joint, the shorter they are cut, the more they will be exposed to the Air and Sun, which will kill them the sooner. Now, what a prodigious Advantage must the Influences of the Atmosphere have upon these small Parts, for making a further Division of them! Frost, Water, Drought, and nitrous Air, easily penetrate to their very Centers, which cannot in the largest of them be more than one Inch and a Quarter distant from their Superficies. This Advantage, with a few subsequent common Plowings, performed in proper Seasons, resolves the Earth almost all to a Powder. The Swerd, some being immersed or buried and mixed among so great a Proportion of Mould, is soon rotten and lost; some of the Swerd lying loose a-top, the Earth presently drops out of it; and then the Roots are dried up, and die. Thus is the whole Staple of the Ground brought into perfect Tilth in a very short time beyond what the Spade ever does in such swerdy Land. Farm. _What sort of Weather is best for using this Plough?_