234 Russell Institution. 



Mr. Bakewell said it might be inferred that the earth is 

 nearly a solid ball, or, if it have extensive cavities, the solid 

 parts are heavier than most metallic substances, and proba- 

 bly contain a very large portion of iron. The opinion 

 which has been lately advanced, that the different earths 

 and alkalies exist in a n)etallic slate in the interior of our 

 planet, and inflame when water finds access to them, was, 

 he conceived, ingenious, but unsupported by much proba- 

 bility. 



The division of rocks into primary, iiitermediate or 

 transition rocks, and secondary, though liable to some ob- 

 jections, Mr. B. said he should follow in the present course, 

 as such an arrangement enabled us to fix more distinctly 

 the different parts of the subject in the memory. 



Each of these divisions he said would be described in the 

 future lectures, and he traced on a geological map of En- 

 gland, drawn for the purpose, the different parts of our 

 island which ihcy occupy. On the eastern side this divi- 

 sion is more di-tinctly marked ; but on the western side the 

 strata are much fractured and intermixed by some unknown 

 cause, which had elevated them in some situations ami de- 

 pressed them in others, and made it difficult to trace their 

 continuity or connexion. According to ibis division, there 

 is a considerable part of the eastern side of our island in 

 which no coal is found, and a still larger division which he 

 traced where no metallic ores exist. Mr. Bakewell said 

 that, so far as he knew, this was the first Attempt to repre- 

 sent in a map the geological outlines of England. 



After explaining the difreretit theories of the earth, by 

 diagrams and descriptions, Mr. Bakewell observed, that 

 they were only Gntilled to consideration so far as they ap- 

 pealed lo facts for their support, and every impartial ob- 

 server of nature must have seen appearances which cannot 

 be explained satisfactorily by any of the systems hitherto 

 advanced. The great changes which the surface of our 

 planet has undergone in remote ages, are confirmed by 

 proofs equally intelligible and impressive, though we are 

 unacquainted with the means by which such changes have 

 been effected. Rocks composed of shells and remains of 

 marine animals form the summits of some of the highest 

 mountains of Craven in Yorkshire, in Derbyshire, and in 

 different parts of the world. The height at which these are 

 found in Yorkshire is 2 tOO feet above the present level of 

 the sea, but or the Pyrenees they are found at the height of 

 10,000 feet. The impressions of marine animals in slate 

 locks present appearances still more curious and difficult to 



explain. 



