Vol. 68.] Al^^NIVEESARY ADDRESS OF THE PRESIDENT. Ixxvii 



■coal was reckoned upon ' its average decremental rate of increase 

 xiuring the last forty years (1861-1901).' The calculation of the 

 amount of ' home consumption coal' was in the first instance ' based 

 on the consumption per head of the population,' and took account 

 of ' the average decremental rate of increase of the population of 

 Great Britain.' In the second series of figures, the population basis 

 was excluded, and the calculation of future coal production was 

 based, as in the case of export, upon its ' average decremental 

 rate of increase during the last 30 years (1871-1901).' 



In the first series the estimated amounts were given in millions 

 of tons as follows : — 



Home Consumption. Exjjort. Total Coal raised. 



Years 1901-2000 29,000 16,000 45,000 



2001-2100 53,000 23,000 76,000 



2101-2200 75,000 24,000 99,000 



Thus, according to the population basis for home consumption, 

 the supply in the proved fields would be more than exhausted 

 l)efore a.d. 2100, by which time 121,000 millions of tons would 

 have been consumed. 



In the second series, the figures (again in millions of tons) are 

 as given below : — 



Home Consumption. Exjjort. Total Coal raised. 



Years 1901-2000 25,000 16,000 41,000 



2001-2100 30,000 23,000 53,000 



2101-2200 30,000 24,000 54,000 



2201-2300 30,000 24,000 54,000 



The calculation thus based results in the more comforting 

 inference that we have sufiicient coal in the proved fields to last 

 over two centuries, while with what would be left over at the end 

 of that period, together with the contents of the unproved coal- 

 fields, we should have enough to last for another century. 



It is not for me to discuss the merits of the two methods of 

 calculation. It is sufficient to remark that the second method 

 seems to accord more closely than the first with the views of the 

 Commission as set forth in the passage quoted above. But it is 

 worthy of remark that the time of any considerable steadying down 

 of the theoretical output is far ahead, and only comes seriously into 

 operation two centuries hence, when the amount of proved coal 

 ' in sight ' of the Commission will be approaching exhaustion. 

 Besides this, a host of unseen factors are likely to arise in the 

 meantime which may altogether vitiate the premises on which the 

 calculations are based. 



