292 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1916. 



briefly trace the progress of production during recent j^ears. We 

 need further to know what the general run of working percentages 

 has been and to answer the questions: Is the yield per ton declining 

 as the years pass, and are we content now to treat ores of lower 

 grade than were our fathers? How do our ores compare in yield 

 with those of foreign productive areas? We can not overlook the 

 vital bearing of our supply of coking coal — a factor in present iron 

 metallurgy not inferior to ore supply itself. We must consider 

 sources of ore outside the United States and yet so situated as to 

 contribute to our furnaces. We must also consider present, or rea- 

 sonably certain future improvements in processes of smelting. No 

 horoscope for the future can be cast without attaching due weight 

 to all these factors. 



The growth in the production of iron ore in the United States has 

 been so great as to be the chief cause of anxiety for the future. The 

 tabulation of a few figures, using a million long tons as the unit, 

 will make the matter clear. Extended statistics are not necessary. 

 I am extremely anxious that the great striking truths should not be 

 lost in a maze of figures. The statistics are taken from the Mineral 

 Resources of the United States Geological Survey. Detailed figures 

 are not attainable for 1888 and earlier years, except in those in which 

 a census was taken. 



In the years before the Civil War the production was small, but 

 shortly after peace was restored the Lake Superior mines began to 

 assume greater and greater importance, and later Alabama developed 

 its mining and smelting industry. 



statistics in millions of long tons. 



