4 BULLETIN 1348, U. S. DEPARTMENT OF AGEICLTLTUEE 
design are still undetermined, and no satisfactory means of meas- 
uring the actual work done in accomplishing this operation has as 
yet been developed. That there exist great possibilities in the more 
efficient designing of farm machinery through careful study of the 
power requirements is suggested by the results so far accomplished 
in the silage-cutter tests now being conducted by the department 
of agricultural engineering of the University of Wisconsin, which 
Billions of Dollars 
25 50 75 100 
Total Investment 
Value Added 
by Manufacture.-? 
Primary 
Horsepower., . 
Annual 
Horsepower-Hours v^^^ 
per vv^v|vvv<> ' lvvj 
Pr'xmzr-^ Horsepower — p i 
Hundreds 
5 !0 15 20 
Horsepower 
5 13 15 20 25 30 35 
Primary Horsepower 
per Worker 
Average Annual 
Hours Work 
per Worker 
Thousands cf Doiiars 
10 
Value of Product Fi 
per Worker. 
Gross Value 
of Product- 
Billicns of Dollars 
25 50 75 MO 
Afer iculture 
Manufactures 
V/////, 
Mining 
Railroads 
L_J 
Number of Workers. 
Annual 
Horsepower-Hours 
Utilized 
ff\/^//\ff^ 
Millions 
2 4 6 8 10 12 
I I I I -T 
Billions 
25 50 75 100 
Investment 
Pr'\m^ry Horsepower 
Horsepower-Hours 
Utilized 
pzr Worker... 
Hundreds of Dollars 
5 10 15 20 
/ / A? f /Wt-t 
Thousands 
5 10 IS 20 25 
Thousands cf Doiiars 
2 4 6 6 ?o 
Investment 
per Worker.. 
j I i .• 
^|\\\\sw 
Thousands of Dollars 
2 4 6 e 10 
Value Added 
by Manufacture 
per Worker.. 
Fig. 3. — Comparison of agriculture with other industries. These values are based upon reports 
of the Fourteenth census of the United States, the Interstate Commerce Commission, and the 
Federal Power Commission 
akeady have shown that the power necessary to cut and elevate 
silage may be reduced at least 50 per cent by employing proper 
speeds and a blower of better design. 
Since power and labor represent on the average approximately 
60 per cent of the total cost of producing farm products, a better 
understanding of the power requirements of farm operations will 
undoubtedly show that great opportunities exist for material reduc- 
tions in production costs thi'ough the adoption of more efficient 
