266 



Report of the Special Coiimpitee. 



Holbrookes Sivivel Plow, JSfo. 4 (Continued). 





■^ 



•73 

 O 



a 





KEMARKS. 



9 

 10 



^11 



tl2 



tl3 

 14 



11 



14 



15 

 15 



12 

 13 



13 



13 



13 

 13 



634 



641 

 660 



482 

 457 



582 



504 



505 

 501 



{The average of the fifth and sixth experiments is 609 

 pounds. Although the sixth is half an inch wider 

 than the fifth, the excess is chiefly due to the turn- 

 ing of the furrow up hill in the sixth. 

 ^ Average of the seventh and eighth experiments, 651 

 \ pounds. 



{Average of the ninth and tenth experiments, 469 

 pounds. The excess of draught of the ninth over 

 the tenth was due to old bones which lay in the 

 bottom of the furrow. 

 {The work without the coulter was very poor; the 

 furrow slice was torn and jagged ; the furrows did 

 not lap well ; the grass was ill covered, and the 

 pulverization was imperfect. 



Work good in all respects. 



( Average of thirteenth and fourteenth experiments, 

 ( 5025 pounds. 



* The coulter was here removed, and the plow was worked, cutting the sod with the 

 shin. 



\ The coulter was here replaced, but was set so that it only penetrated one inch into 

 the soil. 



% The coulter was here brought down within three inches of the sole of the plow. 



.This plow made the best pulverization at a depth of seven 

 inches. It was slightly worse at eight inches; but at depths greater 

 or less than these the inferiority of its work was very marked. 



The average depth of the first ten experiments was 7.05 inches; 

 the average breadth of the first ten experiments was 13.65 inches; 

 the average draught of the first ten experiments was 565 pounds. 



This average draught of all the trials agrees within one pound 

 with the average draught of the third and fourth experiments, 

 which correspond with it in the size of the furrow slice. 

 Recwpitulation of Averages. 



