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ON THE BLOUGH. 2.

move with the fame velocity, and confe- quently to lay off from the broadeft part of them the fame quantity of foil in the fame time; yet the{pace of time that any particle acts againft the longer wedge will be as much longer than the time it acts againft the fhorter, as the obliquity of the former is greater than that of the latter.

What has been proved of the whole wedge muft hold equally true of the half one; for, abftraGiing as before from friCtion, the latter, in the fame circumftances, muft meet with exadtly. half the refiftence of the former.

It feems to follow from this reafoning, that all ploughs which are of equal breadths, whatever their lengths be, fhould be pulled by equal force. This would certainly be the cafe, were the circumftances above mention- ed the whole that fhould be taken into the account, or had the particles of earth, like thofe of fome fluids, little or no friGion a-

mong

AB,FH, the particles a€ting in the direion DE do

it with a greater obliquity, or a fmaller angle DEB, than the particles a€ting in the direGion KL with the greater angle KLH; but the aétion of the for- mer takes place along the longer line BE than HG.