328 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1907. 
The geological evidence may convince us that all the economically 
important iron ores are limited to shallower depths than lodes of gold, 
copper, and tin; but this conclusion shall not enroll me among the 
pessimists as to the future of the iron supply. Twenty years ago a 
paper on the gold supplies of the world was read to the association 
at the request of the Section of Economics. About the time that the 
report was issued there were sixty-eight mining companies with a 
nominal capital of £73,000,000 at work upon the Rand. Nevertheless, 
the author, accepting the view that “ iy future of South African 
gold mining depends upon quartz veins,” concluded: “ There is as 
yet no evidence that the yield will be sufficient in amount to materially 
influence the world’s production. As regards India, the prospect is 
still less hopeful.” 
That quotation may be excused, as it is not only a warning of the 
danger of negative predictions, but of the unfortunate consequences 
that happen when geologists are unduly influenced in geological ques- 
tions by the opinions of those who are not geologists. In economic 
geology, as in theoretical geology, we should have greater confidence 
in the value of geological evidence. Negative predictions are espe- 
cially rash in regard to iron, it being the most abundant and widely 
distributed of all the metals. The geologist who knows the amount 
of iron in most basic rocks finds it difficult to realize the possibility 
of an iron famine; he can hardly picture to himself some future iron- 
master complaining of “ iron, iron everywhere, and not a ton to smelt.” 
There are reserves of low-grade and refractory materials which the 
fastidious ironmaster can not now use, since competition restricts him 
to ores of exceptional richness and purity. When the latter fail, an 
unlimited quantity could be made available by concentration proc- 
esses. The vast quantities of iron ores suitable for present methods 
of smelting in Australia, Africa, and India show that the practical 
question is that of supplies to existing iron-working localities, and 
not of the universal failure of iron ores. 
MINING GEOLOGY AND EDUCATION. 
The genesis of ores and the extent of future ore supplies are inti- 
mately connected questions, and the recognition of this fact has led 
to the remarkable growth of interest in economic geology. This 
wider appreciation of the practical value of academic geology should, 
I venture to urge, be recognized among teachers by giving a more 
honored place to economic geology. 
It was inevitable that until the principles of geology had been 
firmly established, the detailed study of their application should have 
been postponed. Now, however, last century’s work on academic 
geology enables the difficult problems connected with the genesis of 
