184 THE FARMER OF TO-MORROW 



weight, is an important item. While several 

 hundred million acres, rich in every requisite 

 but moisture, are sterile in the Far West, our 

 annual consumption of lumber requires a 

 water-duty of three inches of rain spread out 

 in a blanket that covers the two billion acres 

 of continental United States. 



Thus the timber resources were calculated 

 from the extent of the forests and the rate of 

 growth; the water resources from the flow of 

 streams in cubic feet-per-second translated 

 into foot-pounds of energy; and the mines 

 coal, gold, etc. by cubic measure estimated by 

 trained geologists and engineers. 



The next step was to ascertain, if possible, 

 the extent of the food resources of the nation, 

 as expressed in terms of soil fertility. This 

 question comes nearer home to Jeremiah the 

 Reaper and Jeremiah the Gleaner than any 

 other phase of the inventory of national re- 

 sources. It has to do, first, with his hunger, 

 then with his pocketbook. 



Is the acre, which Jeremiah has mellowed 

 with untold labor, a mine of fertility which he 

 must continually "salt," in proportion as he 

 is successful in applying scientific methods for 

 extracting maximum crops? Is it a bank ac- 



