Vol. 68.] ANNIVERSARY ADDRESS OF THE PRESIDENT. IxxV- 



vl) Taking Pi'of. Jevoiis's calculated rate of probable increase at 3^ per cent. 

 per annum, the supply would only last 110 years, that is till a.d. 1981 (and 

 it was noted that tlie increase in consumption from 1865 to 1869, namely up 

 to 107 millions, had been in agreement with this anticipation). 



(2) If the average arithmetical increase of 3 million tons each year deduced 

 from the known output of the years immediately previous to 1866 were to 

 continue, the period of exhaustion would extend over about 276 years, till 

 A.D. 2147. 



(3) Making allowance, again, for the fact that the population of the country, 

 though increasing rapidly, is increasing at a diminishing rate, the Commission, 

 on the authority of Mr. Price Williams, gave figures which indicated that, 

 if the diminishing rate continued, the supply would last 350 years, to the 

 year 2231. 



(4) Finally, if the rate of extrai^tion and consumption did not exceed that 

 reached by 1870, namely 115 million tons annually, the supply would last 

 ■over 1200 years, that is, till A.D. 3071. 



(6) Royal Commission of 19 01. 



Thirty years after the publication of this first lleport, a second 

 'Commission was appointed in 1901, with similar terms of reference, 

 to revise the estimate of its predecessor in the light of new 

 knowledge and new developmeuts. This body issued its final 

 report in 1905. 



Accepting 1 foot as the limiting thickness for workable seams, 

 .and 4000 feet as the workable depth, as had been done by their 

 predecessors, the Commission in their Report divided the coalfields 

 into three groups under the heads of 'exposed coalfields/ 

 'proved concealed coalfields,' and 'unproved coalfields.' The 

 'exposed' fields and their already ascertained underground 

 extensions (the ' proved ' fields) under post-Carboniferous Form- 

 ations were treated as collective units in each area, and elaborate 

 methods were devised for ascertaining exactly the amount of coal 

 still available in the exposed portions of the fields, and in such 

 -concealed areas as had been actually worked or explored and thus 

 were the subject of definite knowledge. Ready help was given by 

 the majority of colliery owners, managers, and mining engineers, 

 ;and thus it was possible for the Commissioner in charge of each 

 district to draw up elaborate tables for his area. Due allowance 

 was, of course, made for waste in working. Unfortunately, the 

 figures obtained for the 'exposed coalfields' were not separated 

 in the Report from those given for the 'proved concealed coal- 

 fields.' The Commissioners adopted the sensible practice of 

 breaking up the full Report into sections, which can be obtained 



f2 



