114 POWER AND THE PLOW 



Alcohol is derived from vegetable products by distilling a 

 fermented mixture, a large per cent, of the heat value of the 

 original material being lost in the process. Practically all 

 vegetable products contain sufficient cellulose, starches and 

 sugars to yield a considerable amount of alcohol. However, 

 the cost of most raw material is so great as to make its use out 

 of the question. Either it is too valuable for other purposes 

 or the cost of bringing it to the still is prohibitive. 



The sun is hottest at the equator, and since plants can store 

 up only about one fifteen-hundredth part of the heat which 

 streams down upon a given area, we may expect some day to 

 derive the greater part of our alcohol from tropical plants. 

 Aside from this source the need seems most likely to be met by 

 the fermentation and distillation of wood waste, sugar-beet 

 molasses, or potatoes and on the crops bred especially for the 

 purpose. A bushel of such potatoes will produce from two 

 thirds to one and one half gallons of 90 per cent, alcohol. The 

 average production of ordinary table potatoes, even for the 

 state of Maine, is about 275 bushels to the acre, while an acre 

 of German alcohol potatoes often yields as high as 400 or 500 

 bushels. From two to three gallons of alcohol, used in the 

 engine of the future, will suffice to plow an acre, hence one acre 

 may furnish power enough to plow 200. 



To put it another way, the sun stores up power enough in 

 an acre of plants, in a single season, to plow, sow, and harvest 

 that acre for a century, since, for most crops, plowing takes 

 more power than all other operations put together. So long 

 as the sun shines and rains fall, alcohol represents an inexhaust- 

 ible and universal source of fuel, hence, even with the inevi- 

 table exhaustion of our stock of petroleum and coal, there is 

 no cause for alarm. The immense deposits of the latter fuels 

 seem to have been given to the world merely to sustain it until 

 men could learn to use the power of the sun more directly. 



Steel and gasoline made the gas engine a success. All 

 our gasoline comes from petroleum. Neglecting alcohol 



