Supplementary Plow Trials. 



271 



* Many stones in the bottom of furrow. ] This was not quite full depth. 



Average depth from seventy-second to eighty-third experiments, 

 11.5 inches; average width. 12 inches; average draught, 897 

 pounds. 



The average draught of the whole series of experiments falls 

 below the mean of 11 and 12 inches, which corresponds with it 

 in size, 21 pounds. 



Recapitulation of Experiments with Sod and Subsoil Ploiv. 



The average difference in the draught of each inch in depth 

 was 59 pounds. 



The work of this plow at all depths was very perfect; the 

 ground was thoroughly pulverized; the vegetation was perfectly 

 buried, and the surface was left smooth and level as a garden. 

 There can be no doubt that the work was much l)etter done than 

 it could have been done by a spade. 



