2 CHARLES KIRCHOFF 



ranges have been untrod. Under the circumstances, com- 

 parisons are unsafe, but with such it is stating a fact that the 

 United States has been blessed with almost unrivaled re- 

 sources. 



The geographical distribution of our mineral resources 

 could be fairly well shown in maps and charts, so far as ex- 

 ploration and development have revealed them. We might 

 in that way show our assets, territorially distributed, but we 

 would create a very erroneous opinion of their real value. 

 With the most important minerals the economic value of a 

 deposit is dependent upon many other considerations besides 

 those of mere size and extent. Conspicuous among these are 

 accessibility to markets, the means of transportation, natural 

 or artificial, the existence of a supply of lalDor and the char- 

 acter of that labor, climate, the character of the community, 

 its laws, etc. These in their shifting influence find expression 

 in the actual product, and that is a better measure of relative 

 importance than mere location and extent. 



The latter, designated on maps by coloring, is a poor 

 guide since relatively unimportant deposits may cover a very 

 extended territory. Coal measured may underlie many thou- 

 sands of square miles, yet the seams which they enclose may 

 not be numerous nor thick nor possess a coal of satisfactory 

 quality. A field small in area, at some distant place, may bo 

 the scene of enormous operations, while the greater basin roay 

 hardly be able to supply local requirements. The anthracite 

 coal regions, as to area, constitute only an exceedingly small 

 portion of the known coal fields of the United States, yet their 

 importance overshadows any other industrial district. 



Useful minerals are found in deposits which may iii gen- 

 eral be classified, for the purpose of estimating them as assets, 

 into two groups. First are those which are beds constituting 

 one of a series of strata. They are usually persistent and 

 fairly regular over large areas like the coal seams, and there- 

 fore permit of some estimate of their contents. Second arc 

 those whose origin is due to local circumstances, and these 

 include the fissure veins. They are usually irregular, and it is 

 in most cases entirely impossible to arrive at any conclusion 

 of their extent and value without most elaborate under- 



