2O American Economic Association [818 



we may readily determine not only what amount of 

 man-labor was requisite for the production of that crop 

 by the means commonly in use at that time, but also 

 how much barley that same labor-power could have 

 produced by the means commonly in use in the season 

 of 1829-30. The difference between the quantity 

 actually produced in the season of 1895-96, and the 

 quantity which the labor-power required for the work 

 of that season, could have produced by the earlier hand 

 methods, will represent the greater product due to the 

 use of machinery. The crediting of the whole of this 

 difference to the use of machinery is, doubtless, credit- 

 ing it with too much. Credit is due, also, to better 

 methods of cultivation, to pulverization of soils, to the 

 use of fertilizers, to irrigation, rotation of crops, better 

 seed, etc. These are not machine forces although they 

 are largely dependent upon the use of machinery as 

 the use of machinery is, in some degree, dependent upon 

 them. But to attempt the separation of these credits 

 would be much like attempting to determine wliich 

 blade of a pair of shears does the cutting. Moreover, 

 these various other forces play, comparatively, a very 

 incidental and subsidiary part. I believe that the fol- 

 lowing pages will justify this opinion and venture, 

 therefore, to disregard whatever inaccuracy there may 

 be involved in the statement and to say that the entire 

 increased product is due to the use of machinery. 1 



It will be sufficient, for purposes of illustration, to 

 consider only a few of the principal crops in the pro- 



1 For the purpose of this discussion I shall use the term machinery, 

 generally, to signify not only machines, but also tools or implements, 

 and other man-labor saving forces when used as essential adjuncts or 

 parts of machines. For example, horses, when used to draw a reaping 

 machine, will be considered as much a part of the machine as an 

 engine and boiler would be, if used for the same purpose. 



