1821.] 



On Spade Culiivution. 



415 



set at work impi'oveiueut is tiie natural 

 result. 



The month of the spade, if I ruuy so 

 term it, is always a straight line when 

 lie^v ; that is, it is at rioht angles with the 

 two sides, and by that means wlien it 

 meets the ground the wliole lireadth of 

 the spade touches at oace, and if the 

 ground is hard at fhe surface the resis- 

 tance is very considerable. 



To obviate the continual repetition 

 of the exertion necessary to make the 

 spade enter the ground, I have often 

 observed gardeners give the spade an 

 inclinatio"! sideways, and so make one 

 comer enter fir>t. By this means all 

 tlie resistance does not come at the same 

 instant. 



1 have also heard itohserved, and in- 

 deed I haveexperiencctl it myself, that an 

 old spade when the corners of the mouth 

 are worn olT works much more easily 

 than a new one. 



I have th(Mi to recommend that tlie 

 mouth of tlie spa<le should be of the 

 form below i-epreseufed by tlie 



lines i7Ac, or perhaps still more rounded 

 like the dotted line below. 



In addition to the (-videut and un- 

 deniable advantage of the effort or push 

 not being all at once in piercing the 

 surface, tlu'i<; would be the fartlier 

 advantage that resuKs from the sloping 

 or xluntuiir of (lie mouih from a toe, 

 and c to 6, making (Ik; spade to jiene- 

 Inife luori! easily even after it had got 

 wholly into (he ground. 



We know liy exi)erieiice that the 

 form of (he (bees*; hii/e, the. lancet, the 

 hatchet, liiiife^ razor, and various eut- 

 (ing and piercing iustrumenls, tha( a 

 curved line, is much be((er than a 

 straight one for ahiiOs( <;very purpose. 



I think it scarcely iiece-isary to say 

 mudi on thi.'! stibject, but I shall state 

 a fict in illustration that is probably 

 little known. 



When the guillotine was invented in 

 Paris I was there, and remember tliat 

 it was first made with a straight, or if 

 you will, a square cutter. It fell down 

 like a sasii-window, and an experiment 

 M'as made by the College of Surgeons 

 on the body of a sheep, the neck being 

 placed so as to receive t!ie stroke. The 

 trial did not answer the expectation: 

 the sheep was indeed guillotined, but 

 tlie skin of the lower side was not cut. 

 It was squeezed or jammed in between 

 the cutter and tiie edge of the block on 

 v.hich it v.-as laid. The cutter was set 

 fa.^t and required an effort to raise it. 



The report \vas made to the National 

 Assembly, and a slanting cutter re- 

 commended. It was immediately tried 

 on another shee]) and answered every 

 expectation. Tiie skin of tlie neck 

 was cut as clean as if with a pair of 

 large sheers. I read the report at the 

 lime, and to any man who had ever 

 made use of cutting tools, the effect 

 was such as was to be expected. 



When we cut with a knife of which 

 the mouth or edge is straight, we ge- 

 nerally slant it or draw it lengthways, 

 and in using the broad sword or even 

 the sabre, though it has an edge that 

 is curved, the dragoon draws in his 

 arm to make the weapon cut the better. 



Now as a spade must go straight 

 forwanl, I am certain the curve M'ill 

 be better than the straight line. A 

 liatchet when it strikes goes neaidy 

 straight forward, and tiierefore the face 

 of it is always more or less curved in 

 the manner that I recommend for the 

 spade. 



I would also recommend another al- 

 teration in the form of the spade, that 

 is, to make it a little hollow like a 

 goudge such as carpenters and joiners 

 use; a goudge, with the same force ap- 

 plied, cuts much cleaner and easier 

 tlian the flat cliisel. In the ease of the 

 sj)ade it would also have the advantage 

 of giving to it a greater degree of 

 strength, and I apprehend, but am not 

 certain, that tiie earth raised would be 

 broken more completely than with the 

 flat spade. 



^V' i(h r(;gard to the form of the spade, 

 it is not imjuobable (hat it was at some 

 distant period or in some jiarticular 

 coun(ry, (•urved or poinh-d in (he 

 mouth in order to enter the liard ground 

 more easily. The figure called a spade 



