THE PRESIDENTIAL ADDRESS. 29 



in all its previous history, back to the time when Eolithic man first shaped 

 a flint to increase his efficiency as a hunter. 



To save you from the narcotic effect of statistical statements, I will 

 limit myself to one illustration of this generalised statement ; for this 

 special example not only illustrates the rate of general acceleration in 

 exploitation, but introduces an important subsidiary question, namely, 

 the way in which activity is becoming pronounced, if not substantially 

 limited, to a group of special areas. In the year 1870 the United States 

 produced 69,000 tons of steel ; in 1880, IJ million tons ; in 1890, 4J 

 millions ; in 1900, 10 millions, and in 1928, 45 millions. 



Figures like these raise questions regarding the future which would 

 take us beyond our present thesis. For the present we can assume with 

 fair confidence that, taking the world as a whole, the depletion of natural 

 stores is not yet alarming, although the rate of acceleration, by reason of 

 its local variation, forces into prominence some international problems, 

 which will influence, and if effectively tackled will facilitate, the efforts 

 to stabilise conditions of international relations. 



I have elsewhere* made estimates of the quantities of metals stored in 

 that part of the outer film of the earth's crust which may be regarded as 

 reasonably accessible to the miner. The actual figures in billions of tons 

 convey no precise mental impression to us, and need not be quoted here, 

 but certain of the outstanding conclusions have a bearing on our present 

 line of argument. 



The first feature of surprising interest to the man in the street is perhaps 

 the relative abundance of those metals with which he is familiar in the 

 Arts — copper, lead, tin, zinc and nickel. Nickel, in spite of its price and 

 limited use, is twice as abundant as copper, five times as abundant as 

 zinc, ten times as abundant as lead, and from fifty to one hundred times 

 as abundant as tin. There are, indeed, among the so-called rare metals 

 some which are distinctly more abundant than lead, although this is the 

 cheapest of the lot in price, and is consumed at the rate of over a million 

 tons a year. 



And so one gets at once an indication of two important features. 

 Firstly, the miner works only those deposits in which the metal is concen- 

 trated sufficiently to make their exploitation a profitable business ; and 

 secondly, the metalliferous ores vary greatly in the completeness with 

 which they have been concentrated in special places to form workable 



2 Presidential Address, Institution of Mining and Metallurgy, Tratu. Vol. zxziv. 

 1925, p. Ivii. 



