•20 president's address. 



From these figures it appears that the average capital required to 

 produce electrical power from coal is less than one half the amount that 

 is required in the case of water-power. The running costs, however, in 

 connection with water-power are much less than those in respect of 

 coal. Another interesting consideration is that the cost of harnessing 

 all the water-power of the world would be about 8,000 milhons, or equal 

 to the cost of the war to England. 



DowHng has estimated the total coal of the world as over seven 

 million million tons, and whether we appraise it at Is. or more per ton 

 its present and prospective value is prodigious. For instance, at 6s. 3d. 

 per ton it amounts to nearly one hundred times the cost of the war to 

 all the belligei'ents. 



In some foreign countries the capital costs of mining are far below 

 fhe figures I have taken, and, as coal is transportable over long distances 

 and, generally speaking, electricity is not so at present, therefore it 

 seems probable that capital will in the immediate future flow in increas- 

 ing quantity to mining operations in foreign countries rather than to 

 the development of the more difficult and costly water-power schemes. 

 When, however, capital becomes more jalentiful the lower running costs 

 of water-power will prevail, with the result that it will then be rapidly 

 developed. 



As to the possible new sources of power, I have already mentioned 

 molecular energy, but there is another alternative which appears to 

 merit attention. 



Bore Hole. — In my address to Section G in 1904 I discussed the 

 question of sinking a shaft to a depth of twelve miles, which is about 

 ten times the depth of any shaft in existence. The estimated cost was 

 5,000,000L, and the time required about eighty-five years. 



The method of cooling the au'-locks to limit the barometric pressure 

 on the miners and other precautions were described, and the project 

 appeared feasible. One essential factor has, however, been 

 queried by some persons : Would the rock at the great depth crush 

 in and destroy the shaft? Subsequent to my address, I wrote a letter 

 to Nature, suggesting that the question might be tested experimentally. 

 Professor Frank D. Adams, of McGill University, Montreal, acting on 

 the suggestion, has since carried out exhaustive experiments, published 

 in the Journal of Geology for February 1912, showing that in limestone 

 a depth of fifteen miles is probably practicable, and that in granite a 

 depth of thirty miles might be reached. 



Little is at present known of the earth's interior, except by inference 

 fi'O'm a study of its surface, upturned strata, shallow shafts, the velocity 

 of transmission of seismic disturbances, its rigidity and specific gravity, 

 and it seems reasonable to suggest that some attempt should be made 



