Ixxiv PROCEEDINGS OE THE GEOLOGICAL SOCIETY. [JuUG I912, 



the commerce o£ the world, are its wonderful supplies of coal and 

 iron. Indeed, it is not too much to say that coal and iron have been 

 the mainspring of the unexampled growth in all branches of science 

 which marked the nineteenth century. 



(1) Exhaustion of the Coalfields. 



(a) Royal Commission of 1866. 



When the conditions under which coal and iron occur in the 

 earth's crust had become comparatively well known to geologists 

 at the beginning of the second half of the last century, Stanley 

 Jevons, interpreting the economic laws as then understood, 

 predicted the speedy exhaustion of our coalfields, and created so 

 great an apprehension on the subject that the lloyal Commission of 

 1866 was appointed to consider and report upon (1) the amount 

 of coal left available in the coalfields then being worked or likely 

 to exist, (2) the rate of consumption of coal and the possible 

 increase in that rate, and (3) the amount of preventible waste in 

 the processes of extraction and consumption. 



This Commission reported in 1871. It confined its attention to 

 seams not less than 1 foot thick, and considered that 4000 feet 

 was likely to be, in most cases, the limit of depth for profitable 

 w^orkiug. Individual Commissioners dealt with each group of 

 coalfields whether 'exposed' or 'concealed,' and made due 

 allowance for the waste which was found to occur in working the 

 coal. The figures arrived at by the Commissioners were, in round 

 numbers, the following: — 



JMilUons of tons. 



Coal available in exposed fields 90,000 



Do, do. in concealed fields 56,000 



Total 146,000 



In addition to this they estimated that 7000 millions of tons 

 •existed at depths greater than 4000 feet. 



In dealing with the duration of the supply, the Commission 

 indicated several alternative ways of regarding the problem. 

 Among them we note the following, which, however, are placed 

 in a different order from that adopted by the Commission, so as 

 to bring out the wide variation in possible estimates according to 

 the basis taken for calculation. 



