128 Mr. Hopkins's Remarks on Farey's Account of the 



dence and obvious appearances in that part of the boundary 

 to which I have more particularly referred. 



That a great N. and S. fault, however, does exist, I have 

 no doubt, though inferior in importance and very different in 

 position to that which Farey imagined. It is this fault which 

 has brought to the surface the toadstone basset already men- 

 tioned as extending from Copt Hill to the south of Chilmer- 

 ton, and has produced that central elevated ridge which 

 forms the principal feature in the external character of the 

 district. Of this I believe that I shall be able on some future 

 occasion to offer the most indisputable evidence. Farey's ac- 

 count of the great E. and W. fault at the southern extremity 

 of the limestone agrees with my own observations as far as 

 they have yet extended, which is not far west of Hopton ; but 

 whether any N. and S. fault meets this further westward 

 I have not yet ascertained. At the northern extremity of the 

 district, instead of a fault ranging along the whole extreme 

 boundary, an E. and W. one ranges from the north side of Copt 

 Hill, where it meets the great N. and S. fault, to Castleton. 

 That described by Farey as extending from Castleton nearly 

 to Litton, is, I believe, totally unsupported by the slightest 

 evidence. 



If we would allow to a geologist on the one hand unli- 

 mited power of introducing faults, and on the other an un- 

 controlled command of denuding agents, he must be greatly 

 wanting in ingenuity if he could not devise almost numberless 

 systems of stratification for a district like Derbyshire. These, 

 however, are not powers to be delegated to any geologist 

 merely for the purpose of supporting his own theory; but we 

 have seen, notwithstanding, how boldly Farey has asserted the 

 existence of faults without reference to the evidence of facts ; 

 and in his denuding hypotheses we find a character of still 

 greater hardihood. It is manifest that according to his 

 theory, his Jirst, second, and third limestones, together with his 

 Jirst, second, and third toadstones, must necessarily have been 

 swept away by some means from an extensive tract of coun- 

 try, and this too without leaving a trace of the mighty opera- 

 tion behind. Probably he considered also that the shale and 

 gritstone had shared the same fate ; but for all this, and for 

 much more that still continues to puzzle geologists, he con- 

 ceived he had found an adequate cause in the extraordinary 

 hypothesis of a large satellite revolving at so small a distance 

 from the earth as must have rendered him a most trouble- 

 some neighbour; for he accuses him of being, by his powerful 

 attraction, the source of all those disturbances of which such 

 manifest indications still exist on the face of the earth, and 



