512 Mr. Godwin- Austen f on the probability of Coal [April 16, 



alion, as a whole, exceeds that of any other geological group in this 

 country, considered with reference to surface. 



What is coal ? It is pure vegetable matter — the product of 

 plant-growths. And with respect to the mode by which it has been 

 accumulated, two theories have been proposed : there is the " drift " 

 theory, which accounts for its occurrence as the accumulations of 

 vegetable matter, brought down by mighty rivers, and deposited in 

 lakes and sea-margins. There is something too turbulent in this 

 theory to account for our great seams of fossil fuel. 



The other theory is, that coal is the product of a vegetation 

 which grew upon the very spots, and covered the areas over which 

 our coal-beds extend, like the peat-beds of the present day. This is 

 the theory of M. De Luc, M. Ad. Brongniart, and Messrs. Lindley 

 and Hutton. 



In supposing that coal originated as peat, all that is meant is, 

 that it is the product of a vegetation composed of like plants, such 

 as could live on in association over the same spots, growing above 

 and decaying beneath ; but differing as widely in the plants which 

 composed it from our present peat plants, as did the whole of 

 the vegetation of that period from that of the present period : the 

 huge stigmarise are wholly unlike any plants which commence the 

 peat growth now. 



The succession of a coal-field may be seen in a small scale in 

 the deposits of lakes which have had differences of level from local 

 accidents ; and with reference to extent Ireland may be taken as an 

 illustration of continuous masses of vegetable matter, of vast thick- 

 ness, covering the whole country for 50 miles, and at low levels. 

 Depress Ireland ever so little, so that the waters of the sea should 

 reach in in some places, and the river waters, such as those of the 

 Shannon, should collect into lakes ; and just in proportion as the 

 water was shallow would an uniform stratum of sand, or silt, or 

 gravel, be spread out above the peat-growths. 



The history of the coal-fields of this and every country, is that 

 of an endless succession of such changes. 



The question of the probable existence of coal measures at any 

 given spot over the European area depends primarily on the 

 original form of the surface of these coal growths : in other words, 

 can we construct a map of Western Europe for the coal measure 

 period ? 



The restoration of the physical features of a portion of the 

 earth, for any given past period, is not so difficult, nor so purely 

 speculative as some may imagine : every form and combination of 

 mineral materials composing the sedimentary formations, all the 

 forms of life they contain, serve to indicate the precise conditions 

 under which they have been accumulated. Shingle and gravel 

 mark marginal zones, sand zones mark lower or submarginal 

 regions, deep sea deposits consist of mud or oaze ; thousands of 

 persons who have never even heard of the inquiries of the geolo- 



