443 , OF DRILL-PL OUG HS. Part IV. 



M. Duhamel does not fix the diameter of the hind wheels, but 

 leaves that to be determined by the length of the fliares. His were 

 fo proportioned, that when the {hares touched the ground, the wheels 

 did not touch it by two inches. He obferves, that this drill anfwered 

 extremely well, where the ground was plowed into an even or level 

 furface : but that the wheels were too fmall when the middle of the 

 beds were raifedj becaufe the fliares were then on the higher part of 

 the bed, while the wheels were in the furrows. 



In^^. 3 and 4, are two thin boards x, x, fomewhat bending, 

 which rife up to about half the height of the barrel. The ufe of 

 thefe is to catch the feeds that may chance to drop from the oblique 

 holes, -and guide them into the cavities a, c, b. 



It is well known, that when the fore part of the fhare terminates 

 in a point, it pierces the deeper into the earth, the farther back the 

 beam is placed on the fore-carriage : but as the bottom of our fhares 

 is round, they pierce neither more nor lefs when the beam is placed 

 more forward. It is therefore advifeable to place the fore and hind 

 •carriage as near as poffible to one another, becaufe the plough then 

 goes eafier, and the draught is lighter to the cattle. 



This inflrument is eafily tranfported from place to place by means 

 of two poles, _)/, z, z.,Jig. 3. The ends y are placed on the fore- 

 %arriage together with the beam, and from thence pafs under the 

 '^;ible, fo as to raife the whole from the ground, on which their other 

 -ends Z; z, reft. The crofs bar k, k, fecures thofe ends, and keeps 

 them at a proper diftance. 



In the conftrudtion of the above inftrument, as given by M. Du- 

 hamel, the fliares muft always pierce to the fame depth, becaufe the 

 whole weight of the hind part of the drill refts continually upon 

 them : confequently, it would be neceffary to have fhares of as many 

 different lengths, as there are depths at which each kind of feed 

 fhould be fowed. 



We apprehend, that when the fliares have pierced to the depth in- 

 tended, the weight of the drill may be made to reft on the wheels, 

 l3y preventing the axle tree from rifing between the ftandards, beyond 

 fuch a height as fhall exaftly regulate the depth to which the fhares 

 are to pierce. This may be effedled^ by bringing the ftandards /, /, 

 Jig. 4, nearer to each other; and placing between them, inftead of 

 the blocks «, n,fg. 5. two thick pieces of wood, made to flide up 

 and down, with grooves, as in the blocks. Thefe pieces of wood 

 may be nxad between the ftandards, by means of two ftrong iron 

 ~i/\ Vi ^ - pins 



