THE IRON-ORE SUPPLIES OF THE WORLD 379 



supplies would only last another fourteen years, though the 

 potential supplies, which have been crudely estimated, including 

 250 million tons in India, would last another six or seven years. 

 But when the lower-grade ores are included, the total actual 

 reserves of iron are estimated at over 10,000 million tons, and 

 the potential at 50,000 million tons, exclusive of enormous 

 supplies which are still unmeasured and may amount even 

 to ten times that great amount. The known supplies, at the 

 present rate of production, would last two hundred years. 

 Including the potential reserves, they would last over a thou- 

 sand years ; by lowering the grade of ore that iron-masters are 

 willing to smelt, ample ore supplies would be available for 

 further millenniums. 



These estimates fully confirm the opinion expressed to 

 the Geological Section of the British Association in 1907, when I 

 remarked that — 



" The geologist who knows the amount of iron in most basic 

 rocks finds it difficult to realise the possibility of an iron famine ; 

 he can hardly picture to himself some future ironmaster com- 

 plaining of iron, iron everywhere and not a ton to smelt.' There 

 are reserves of low grade and refractory materials which the 

 fastidious ironmaster cannot now use, since competition restricts 

 hirn to ores of exceptional richness and purity. When the 

 latter fail, an unlimited quantity could be made available by 

 concentration processes. 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." ^ 



The future demands on the world's supplies of iron ore will 

 be affected by industrial changes and on those of separate 

 countries by their financial policies. Thus the introduction 

 of reinforced concrete must materially diminish the demand 

 on the iron ores. The adoption of a protectionist policy by a 

 country may lead to the development of its own iron mines and 

 perhaps the closing of those of some of its neighbours. Thus 

 the imposition by the United Kingdom of a tariff on imported 

 iron ores would no doubt lead to the working of British ores 

 that now lie unutilised and might close some Mediterranean iron 

 fields which can only mine iron ore for export, having neither 

 fuel supplies nor water power. 



' Presidential Address to Section C, Rep. Brit. Assoc. 1907, p. 501. 



