4.1)8 Farm Mechanics. 



Even in an equalizer where the three holes are only one 

 inch out of line an angle of 20 for the evener with tbe 

 line of draft may give the horse ahead nearly as much ad- 

 rantage as would result hy setting the clevis of the other 

 horse in toward the center one inch. 



When the holes for the clevis pins are in front of the 

 draft pin a similar inequality of division of labor occurs, 

 but in this case the horse which is in front must pull the 

 most, the differences measuring as great as with the other 

 type. When the three pins are placed in a straight line 

 there is nearly a true division of labor between the horses, 

 even when the angle formed by the evener is large. This 

 statement, however, is only true when the clevis pins and 

 the draft pin fit the holes closely. 



621. Giving One Horse the Advantage. When it is de- 

 sired that one horse shall do more work than the other this 

 is accomplished by shortening the lever arm of the horse 

 ivhich it is intended shall do the larger share of the work. 

 If it is desired that the off horse shall do 60 per cent and 

 the near horse 40 per cent of the work then the clevis pin 

 of the off horse must be set in until the two ends of the 

 3vener are in the reverse ratio, or as 40 to 60. 



If the evener is 48 inches long the two arms would be 

 each 24 inches. From the equation of the lever we have 



PX PA = WX W A 

 and 60 X P A = 100 X 24 



whence 60 X P A = 2, 400 



and P A = 40 



From this is appears that the clevis must be set in 

 48 40 = 8 inches, 



which leaves the off horse with a weight arm of 16 inches 

 and the near horse with one of 24 inches. 



