Practical Questions in Plows and Plowing. 155 



wide, showed a draught in a sandy loam of 266 pounds; a loamy 

 sand, 266 pounds; a moory soil, 322 pounds — increase, 21 per 

 cent; a strong loam, 490 pounds — increase, 84 per cent; a blue 

 clay, 700 pounds — increase, 163 per cent. 



In our trials, Collins k Co.'s steel plows, with a furrow twelve 

 inches wide and twelve inches deep, showed a draught in an 

 indurated clay soil, mixed with coarse gravel, of 613 pounds; 

 an unctuous tough clay of 705 pounds, the increase being 15 per 

 cent. Holbrook's plow, taking the same furrow, and in the same 

 soil, showed a draught in clay and gravel of 615 pounds; unctuous 

 clay of 671. pounds; difference 9 per cent. 



From these data it is obvious that the draught of plows taken 

 ill (liferent soils cannot be compared with each other since the 

 diflerence in the power required to overcome their cohesion has, 

 by actual trial been found to extend to one hundred and sixty- 

 three per cent, and it is quite probable that future trials may 

 disclose even wider diiferences than this. 



In answer to our second question, " What is the power required 

 to draw difierent plows through the same soil, with furrows of 

 equal size, we have the following experiments by Mr. Pusey. 

 The furrow was five inches by nine inches: 



We learn from this table that there is a difference between 

 plows in the same soil, and with equal furrows of forty-six per 

 cent in the extreme case of the Old Berkshire as compared with 

 Hart's one wheel Berkshire, while the average difference in the 

 drauG;ht of nine plows was tweuly-three per cent. 



