220 PRINCIPLES OF RURAL ECONOMICS 



altogether probable that he can, with no greater fatigue to him- 

 self or to either horse, plow two acres with two horses, using 

 a larger plow. A little time would be lost in feeding, cleaning, 

 harnessing, hitching, and unhitching two horses rather than 

 one, but the loss of time would be so slight as to be almost 

 negligible. With three horses to care for, feed, harness, etc., 

 the loss of time begins, let us say, to be appreciable, and unless 

 the man works longer hours he will not be able to plow three 

 acres with three horses, even though he uses a larger plow. 



We are, for the moment, leaving out of consideration the 

 probability that a large plow pulls more than proportionally 

 harder than a small one, owing to the greater height to which a 

 large sod has to be lifted in order to turn it over. With the 

 same amount of time a man will, let us say, plow not 3 acres 

 but 2 J- ; and for trie same reasons he will plow with 4 horses 

 not 4 acres but 3|, with 5 horses not 5 acres but 4^, with 6 

 horses not 6 acres but 4|, with 7 horses not 7 acres but 5|, 

 and with 8 horses not 8 acres but 5|. Of course, by getting 

 up earlier in the morning to do the preliminary feeding and 

 harnessing, by allowing himself a shorter noon hour because of 

 the feeding and watering of the larger team, and by working 

 longer in the evening after the return from the field, he may 

 succeed in maintaining a fixed proportion between the number 

 of horses and the number of acres plowed ; that is, he might 

 succeed in plowing one acre per horse regardless of the size of 

 the team. But working longer hours in this case would mean 

 doing more work, which, economically speaking, is the same as 

 increasing the number of men. 



Under the assumptions which we have made, it will appear 

 that the addition of the second horse added I acre to the. 

 amount plowed with one horse, the addition of the third horse 

 added | of an acre to the amount plowed with two horses, the 

 addition of the fourth horse added f of an acre to the amount 



