54 O F P L O W I N G. Parti. 



theatre, are better enabled to receive the influences of the air, 

 which certainly is of fervice to vegetables. 



' We fliall not infift on the perpendicular growth of the ftalks of 

 plants, though we believe it real. But to lliew Mr. Tull, how 

 inconfiderable the advantage ot what he recommends would be, we 

 ■will fuppofe the furrows of a piece of ground plowed in broad-lands 

 to be lix inches deep, and the ridges fix feet wide. The flope from 

 tlie bottom of the furrow to tlie middle of each ridge will be one 

 foot in fix, which is confiderable : but ftill the lurface of the ridges 

 *'will be to that of their horizontal bafe, only as 76 to 75. This 

 is a fmall advantage, compared to a fixth of the ground, which is 

 taken up by the furrows, and in which no corn is planted. 



But, as in all this we confider lands only relatively to the common 

 method of culture, it muft be owned, that Mr. Tull might full as 

 well not have entered into this queftion, which is quite foreign to 

 the purpofe in hand, fmce, even according to his own principles, it 

 is beft not to fow above one third of the furface of any land. 



The defign of tillage, is, to deftroy weeds, and to reduce the earth 

 to very fmall particles. The fpade is very fit for thefe purpofes, 

 becaufe, by turning the ground upfide down, the weeds are covered 

 with a quantity of earth, under which they rot, Befides, it ftirs the 

 mould eight or ten inches deep. But this operation is tedious, labo- 

 rious, and expenfive ; fo that it can be ufed only in gardens. 



The plough is more expeditious ; but, in general, it does not ftir 

 the earth fo deep, and often turns it over in one great clod, without 

 breaking it into pieces ; for the coulter cuts the turf, the fliare 

 which follov/s opens and raifes it up, and the mould-board turns it 

 over all in a lump. — Mr. Tull has endeavoured to improve this til- 

 lage ; and to that end he has invented a plough with four coulters, 

 inftead of one. Thefe coulters are placed in fuch a manner as to 

 cut the earth which is to be opened by the fhare, into flips of two 

 inches breadth ; fo that when the plough opens a furrow of feven 

 or eight inches wide, the mould-board turns over a well divided 

 earth, which does not fall in large clods, as after the common plough. 

 The confequence of this is, that, on a fecond plowing, the plough 

 turns up an earth already confiderably broken, inftead of meeting 

 with clods, and even turf, which, having taken frefli root fince the 

 former plowing, is as difficult to break, as if the earth had never 

 been plowed. 



We 



