34* Of t7 ° e Drill-Boxes. Ghap. XX. 



their Number ; yet we cannot lefTen the Proportion 

 of Seed by the Notches, unleis we have a new Set of 

 them, and that will occafion a Neceffity of having 

 another Spindle ; but, as to the Setting- fcrew of the 

 Turnep-drill, it will increafe the Proportion of Seed, 

 with the fame Notches, much more than the Setting- 

 fcrew of the Wheat-drill will do. 



The other Way of varying the Proportion of Seed, 

 in the fame Boxes, is by the Diameter of the Wheels, 

 when we can alter them ; for Wheels, of what Dia- 

 meter foever they are, muff, turn round all the Notches, 

 at one Revolution ; fo that Wheels of Twenty Inches 

 Diameter will deliver out a third Part more Seed than 

 Wheels of Thirty Inches Diameter, into the fame 

 Length of the Chanels; but we feldom have any 

 Occafion to alter the Wheels, unlefs it be on account 

 of planting a Species of Seed of a different Magni- 

 tude, as the largeft Sort of Peas, and fmall-grain'd 

 Wheat, or St. Foin Seed are. 



Thefe are all the Ways we have to alter the Pro- 

 portion of Seed, we drill with the fame Seed-boxes -, 



double Set of Notches in a fmall one one. The largeft Spindle I 

 have known made, is of Two Inches and an half Diameter, and 

 that only for Horfe-Beans. 



The bcft Sort of Notches for a double Set are thofe which 

 have convex Bottoms ; becaufe fuch are lefs liable to drop their 

 Seeds without the turning of the Wheels, than any other Sort : 

 And a double Set muft be in greater Danger of this, as the 

 Tongue is always hindered from prefiing fo clofely againft any 

 Notch, being held open by the Seeds on the oppofite Interftice ; 

 which is contrary to a fingle Set, where no Seed can lodge at 

 cither End of a Notch, to hold open the Tongue, or hinder its 

 preffing againft it. 



Note, When I made my Boxes of Wood, I had double Boxes, 

 with a Partition between fuch a double Set of Notches ; but never 

 made fuch in Brafs, not knowing whether that Partition, by its 

 Thinnefs of hard Metal, might not cut the Spindle :. Yet I never 

 found any Occafion for a double Row of Notches. I made thofe 

 double Boxes only for drilling Two Sorts of Seeds at once into the 

 lame Chanel. 



thefe 



