216 Report on Trials of Plows. 



indicated in the first table for Holbrook's plow is 328 pounds. 

 The mean result for Collins' plow is 403 pounds, making a differ- 

 ence of 75 pounds in favor of Holbrook's. 



The mean average result according to the second table for Hol- 

 brook's plow is 672 pounds, and for Collins' 638 pounds, making 

 a diflerence of 34 pounds in favor of Collins. 



Before the dynamometer was applied it was the opinion of 

 several of the judges who consulted on the subject that as the 

 soil on the lower or southern end of the lot was the most homo- 

 geneous that the inditations of the dynamometer while passing 

 through it would give the best indications of the relative power 

 consumed by each plow, and it was accordingly resolved to make 

 separate ol)servations upon it. 



On comparing the power consumed by each plow while passing 

 through the more homogeneous portion of the furrow it will be 

 •seen that the average draught of Holbrook's plow was 590 

 pounds, while the average draught of Collins' was 636 pounds, 

 showing a difference in favor of Holbrook's of 46 pounds. 



SUMMARY. 



By the first table Holbrook has the advantage by 75 pounds. 

 By the second table, in " loosest soil," Holbrook excels by 46 

 pounds. By the second table, the general average, Collins excels 

 by 34 pounds. 



The question to be determined is, which of the plows is of the 

 easiest draft? 



From the indications of the first table it would seem that the 

 Holbrook plow has the preference, but Collins' plow turned over 

 twenty-one square inches more than Holbrook's and hence appears 

 to do more work with less power. It appears from the experi- 

 ments of Mr. Morton that only ten per cent of the power required 

 for plowing is expended in turning over the sod, while the remain- 

 ing ninety per cent is absorbed by friction and by the clearage of 

 the soil. If this statement of Mr. Morton's is correct, then it 

 would be incorrect to assume that the poAver required is in pro- 

 portion to the square inches in the furrow slice, and therefore the 

 indications of the second table would not he correct. 



A majority of the judges therefore decided that the Holbrook 

 plow had the lightest draught, and they were confirmed in this 

 conclusion by the fact that in the homogeneous soil even by the 

 second table the Holbrook ph)w was shown to be the b'ghtest. 



