THIS BULLETIN has been prepared under the 
direction of the committee on farm power, ap- 
pointed by the Secretary of Agriculture to represent 
the Bureau of Public Roads, the Bureau of Agricul- 
tural Economics, and the Bureau of Animal Industry 
in a cooperative study of all phases of the farm- 
power problem. 
Agriculture in the United States uses practically 
as much primary power as all manufacturing and 
central station plants combined. The cost of using 
this power amounted to approximately $3,000,000,000 
for the year 1924. However, by the aid of this power 
the average agricultural worker has been enabled to 
increase his volume of production nearly three times 
over the average of 75 years ago. Powder and labor 
together represent on the average about 60 per cent 
of the total cost of carrying on the farm business, 
and, since these are two items directly subject to the 
control of the farm operator, great opportunities 
exist for the cutting down of production costs 
through a better understanding of the power re- 
quirements of farm operations, through the adoption 
of more efficient and less expensive types of power 
units, and by a more extensive use of power to 
replace human labor. 
H. C. Taylor, Chief, 
Bureau of Agricultural Economics, 
E. W. Sheets, Chief, 
Animal Husbandry Division, 
Bureau of Animal Industry, 
Thos. H. MacDonald, Chief, 
Bureau of Public Roads, 
Department Committee on Farm Power, 
