STRUCTURE OF ENGLAND AND WALES. 2/ 



The deductions of geology rest upon the accumulation of a 

 vast number of facts — facts which in themselves are often dry 

 and tedious. Thus the very detailed work of the Palaeon- 

 tologist — the determination and description of species of 

 organic remains — derives its interest and importance from 

 the light that any fossil or set of fossils may throw upon the 

 past history of the earth, or upon the development of life. 

 The intimate structure of a rock is interesting and important, 

 as it sheds light on the character of the deposit of which it 

 is a fragment, whether formed by volcanic agency, by rain, 

 river, or sea. 



Geology has, however, a practical aspect. The habits and 

 industrial pursuits of the people are largely dependent on the 

 nature of the land, and consequently on geology. The 

 mining population is chiefly in the western half of the 

 country, and the agricultural chiefly in the east, if we draw 

 a line between Flamborough Head and Lyme Regis. While 

 the manufactures are chiefly in the northern and midland 

 counties, in proximity to the principal coal- and iron-pro- 

 ducing strata. 



Among the Economic purposes of Geology are its applications 

 to Engineering, Architecture, Agriculture, and Mining. In regard 

 to drainage and water-supply, in the selection of sites for building, 

 in the formation of canals, and in the making of roads, railway- 

 cuttings, and tunnels, a knowledge of Geology is most useful. So 

 also in the selection of building-stones, where the mechanical 

 structure of the rock has to be taken into consideration. 



Our Geological Maps display the superficial exposures of Lime- 

 stones adapted for building-purposes and lime ; of Marls for 

 agricultural purposes ; of Clays and Loams used in the manu- 

 facture of bricks, tiles, and pottery ; of Slates for roofing and other 

 purposes ; of Marbles for ornamental purposes ; and of Granites 

 used for building, for road-metal, etc. 



The prospects of Coal and the supply of Metals are questions 

 towards the solution of which Geology lends great assistance. 

 There are, however, many minor applications of the Science to the 

 Arts and Manufactures, which will be mentioned in the sequel. 



When the philosophy of Geology is understood, its history 

 can be appreciated, and without reference to details. We 

 soon learn that the science does not consist in the mere 

 collecting and naming of rocks and fossils ; but that it 

 ultimately aims at restoring in imagination the successive 

 changes through which the earth has passed, at picturing the 

 different distribution of land and water in each period, the 

 changes in climate, and the character of the animal and 

 vegetable life that has existed. Finally it deals with the 



