THEIR ECONOMIC IMPORTANCE. 175 



of consumption the present increasing demand will be 

 somewhat restrained ; that with improved methods of work- 

 ing much of the mineral now left underground will "be 

 raised ; and that with more skilful engineering deeper 

 shafts may he sunk through the overlying secondary rocks. 

 But even with all these appliances no man of intelligence 

 can shut his eyes to the facts that we are rapidly working 

 out our best and most accessible coal-seams, that deeper 

 winnings must entail greater expense, and that in less than 

 a century hence the price of British fuel will be immensely 

 increased. How long the supply may be sufficient to sus- 

 tain the supremacy of British industry it is impossible at 

 present to determine, but assuredly two or three hundred 

 years hence all the more accessible portions of our coal- 

 fields will be thoroughly exhausted, and our successors will 

 be driven either to foreign fields, to other sources of heat 

 than coal, or to other centres of industry. No doubt the 

 vast fields of America and Australia are scarcely broken in 

 upon,* and science is every year discovering newer fields in 

 other regions, and this will tend greatly to lessen the pres- 

 sure on those of Great Britain ; but still the results must 

 ultimately be a change in our commercial relations and a 

 shifting of the theatres of manufacturing industry. Under 

 a wide and cosmical view, however, such changes are in- 

 evitable, and we need no more disquiet ourselves about the 

 future condition of our country than about the future dis- 

 tributions of the seas and continents. The rise and decline 

 of nationalities and the phases of their commercial power 



* The available coal areas of Great Britain are usually estimated at 

 little more than 5000 square miles ; those of North America alone 

 exceed 200,000 ! When we add to this the unknown areas of South 

 America, of Australia, of Japan, China, and India, to say nothing of the 

 partially explored fields of Russia and Austria, the reader will readily 

 perceive how immense the stores of fossil fuel laid up for the future 

 requirements of human industry. 



