i873-] Limits of our Coal Supply. 347 



of British coal supply, which is likely to arrive long before 

 we reach a working depth of 4000 feet. 



The Royal Commissioners estimate that within the limits 

 of 4000 feet we have hundreds of square miles of attainable 

 coal capable of yielding, after deducting 40 per cent, for 

 loss in getting, &c, 146,480 millions of tons ; or, if we take 

 this with Mr. Hull's deduction of one-twentieth for seams 

 under two feet in thickness, there remains 139,000 millions 

 of tons, which, at present rate of consumption, would last 

 about 1200 years. But the rate of consumption is annually 

 increasing, not merely on account of increasing population, 

 but also from the fact that mechanical inventions are per- 

 petually superseding hand labour, and the source of power 

 in such cases is usually derived from coal. This considera- 

 tion induced Professor Jevons, in 1865, to estimate that 

 between 1861 and 1871 the consumption would increase 

 from 83,500,000 tons to 118,000,000 tons. Mr. Hunt's 

 official return for 1871 shows that this estimate was a close 

 approximation to the truth, the actual total for 1871 having 

 been 117,352,028 tons. At this rate of an arithmetical in- 

 crease of three and a half tons per annum, 139,000 millions 

 of tons would last but 250 years. Mr. Hull, taking the 

 actual increase at three millions of tons per annum, extends 

 it to 276 years. Hitherto the annual increase has followed 

 a geometrical rather than arithmetical progress, and those 

 who anticipate a continuance of this allow us a much 

 shorter lease of our coal treasures. Mr. Price Williams 

 maintains that the increase will proceed in a diminishing 

 ratio like that of the increase of population ; and upon this 

 basis he has calculated that the annual consumption will 

 amount to 274 millions of tons a hundred years hence, and 

 the whole available stock of coal will last about 360 years. 



The latest returns show, for 1872, an output of 

 123,546,758 tons, which, compared with 1871, gives a rate 

 of increase of more than double the estimate of Mr. Hull, 

 and indicate that prices have not yet risen sufficiently to 

 check the geometrical rate of increase. Mr. Hull very justly 

 points out the omission in those estimates which do not 

 " take into account the diminishing ratio at which coal 

 must be consumed when it becomes scarcer and more ex- 

 pensive ;" but, on the other hand, he omits the opposite 

 influence of increasing prices on production, which has been 

 strikingly illustrated by the extraordinary number of new 

 coal-mining enterprises that have been launched during the 

 last six months. If we continue as we are now proceeding, 

 a practical and permanent coal famine will be upon us within 



