POWER AND THE FOOD SUPPLY 285 



hours consumed in forward progression and useful work is a 

 minimum figure for the acre, three billion for the nation. Only 

 40 per cent, of the area of continental United States will be 

 improved in 1940, according to Mark A. Carleton, cerealist 

 of the United States Department of Agriculture. Deeper 

 plowing must be universal twenty horsepower-hours to the 

 acre must be the rule instead of the exception fifteen billion 

 horsepower-hours the amount of power spent annually in 

 turning the soil if the nation is to be fed. Twenty-three mil- 

 lion work horses must be used for one thousand hours per 

 year, ninety to one hundred and fifteen millions for the 

 hours now available for plowing, if the work is to be done by 

 animal power. 



For each work horse and the surplus needed to keep up the 

 supply, five or more acres of harvested crops are required for 

 support. Greater animal power applied to each acre will 

 increase the yield, but not so fast as it will multiply the number 

 of animals required to produce that power within the brief 

 plowing season. We can even conceive that with the highest 

 possible yield secured by the application of animal power to 

 the plow, the area required to maintain the animals will leave 

 little or nothing for the production of human food. The 

 percentage of the total area devoted to power production 

 must decrease, rather than increase. More acres must be added 

 to our farm area, more bushels garnered from every acre, and 

 less fed to unprofitable animals if we are to maintain our place 

 among the prosperous nations of the world. 



The animal muscle has reached its present perfection 

 only after ages of natural selection, extending back to the 

 very dawn of life. Centuries of breeding and selection by man 

 have advanced the animal in size, but otherwise only to a 

 slight degree in efficiency. Further perfection must be slow, 

 individual rather than racial. Many mechanical motors already 

 surpass the horse in commercial efficiency some in the 

 ability to convert latent chemical energy into useful work. 



