FOREWORD 



Mineral resources are coming more and more into prominence as 

 the basis upon which modern advance is built. Their adequate 

 development is a matter of the first importance and public opinion 

 will be called upon in increasing measure to shape the course of 

 advance in this fundamental field. As the general subject is not 

 one of popular experience, this series of papers is under preparation 

 for the purpose of interpreting in nontechnical language the signifi- 

 cant aspects of each resource of mineral origin, in anticipation of a 

 growing demand for concise summations of technical knowledge in 

 a form adapted to current use. 



The two most important resource problems facing this country 

 to-day concern the supply of energy (fuel and power) which under- 

 lies the employment of all raw materials, and the supply of fertilizers, 

 which conditions the output and cost of food. This paper (Bulletin 

 102, volume 1) is designed to present a constructive analysis of the 

 energy situation in the United States, while its successor (Bulletin 

 102, volume 2) will be charged with a consideration of fertilizers in 

 their bearing upon the food supply of the Nation. 



The Authoks. 



August 1, 1918. 



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