436 Our Future Coal Fields. 



ironstone. A certain portion of each coal field has been 

 exhausted ; the produce per year is so many tons, and is con- 

 stantly increasing. From these data the duration of the 

 minerals known to exist beneath any given surface can be 

 easily estimated with tolerable precision. If then, the cal- 

 culations of so eminently practical a man as Sir W. Armstrong 

 should be thoroughly reliable, and not overdrawn, we naturally 

 ask what will become of the principal manufacturing industries 

 which now contribute so largely to our national wealth and 

 prosperity ? 



There is no fear that any dearth of fuel will be felt in our 

 day, even should we have to depend entirely upon the known 

 coal-producing areas ; but if no new tracts are opened up, our 

 descendants will, at no distant date, have to cope with a coal 

 famine, which will speedily drive some of our most important 

 manufactures into other localities. These were considerations 

 which the address above-mentioned did most certainly excite 

 in the minds of not a feAv practical men, and hence, since the 

 last meeting of the British Association at Newcastle, a great 

 amount of careful attention has been devoted to all questions 

 by which the duration and probable extension of our coal- 

 fields would be elucidated. The result has been the accumu- 

 lation of many interesting and valuable facts, especially relative 

 to the circumstances under which the numerous isolated coal 

 tracts in this country were formed, and received their present 

 configuration. A close relationship has been traced between 

 several of these districts, and it has been pretty clearly 

 demonstrated that a considerable portion of the Carboniferous 

 formation is now obscured by newer deposits. To enter into 

 details respecting all that has been done in this particular line 

 of research would exceed the limits of this paper ; but the 

 subject is one of such national importance that we would 

 briefly notice a few of the conclusions which have been drawn, 

 or more fully established, from the investigations of the past 

 few years. 



In the first place, it is now the generally received opinion 

 that all the Northern and Midland coal-fields belong to the 

 same geological period, and were deposited originally in one 

 extensive area, local causes producing variations in the cha- 

 racter of the vegetable remains, in the extent of the several 

 coal seams, and in the thickness of the intervening beds of 

 sand and clay. This large carboniferous estuary or lake was 

 afterwards strangely dislocated by the igneous action which 

 produced the long line of mountain limestone and millstone 

 grit hills now forming the Pennine range, or the backbone of 

 England. In the gradual elevation of this central portion of 

 the basin, the coal measures overlying the limestone would be 



