Turning now to one of the only two 

 sources of wealth, the mine, we find it differing from 

 the others in an important essential. It is inftptMt 

 of restoration or recuperation. The mineral wealth 

 stored in the earth can be used only once. When iron 

 and coal are taken from the mine, they cannot be re- 

 stored ; and upon iron and coal our industrial civiliza- 

 tion is built. When fuel and iron become scarce and 

 ln-h i triced, civilization, as far as we can now foresee, 

 will suffer as man would suffer by the gradual with- 

 drawal of the air he breathes. 



The exhaustion of our coal supply is not in the in- 

 definite future. The startling feature of our coal pro- 

 duction is not so much the magnitude of the annual out- 

 put as its rate of growth. For the decade ending in 

 1905 the total product was 2,832402,746 tons, which 

 is almost exactly one-half the total product previously 

 mined in this country. For the year 1906 the output 

 was 414,000,000 tons, an increase of 46% on the aver- 

 age annual yield of the 10 years preceding. In 1907 

 our production reached 470,000,000 tons. Fifty years 

 ago the annual per capita production was a little more 

 than one-quarter of a ton. It is now about five tons. 

 It is but eight years since we took the place of Great 

 Britain as the leading coal-producing nation of the 

 world, and aleady our product exceeds hers by over 

 43%, and is 37% of the known production of the world. 

 Estimates of coal deposits still remaining must neces- 



y be somewhat vague, but they are approximately 

 near the mark. The best authorities do not rate them 



