2 On the Shelves of Lochaber. 



collect additional facts to support my ideas. During the 

 time that has since elapsed, the observations of geologists 

 of the travelled and water-worn materials which so abun- 

 dantly cover the globe, have been considerably extended ; 

 and the results have contributed to confirm me in the belief 

 that my explanation was well-founded. Mr David ]Milne 

 has made an extensive and careful examination of the Loch- 

 aber phenomena, and has given the result of it to the public 

 in the Transactions of the Royal Society of Edinburgh, and 

 in Jameson's Journal. As all that he has decribed appears 

 to me to favour my own views, a nearer approach to truth 

 may be made, if I now submit these views to the considera- 

 tion of those who take an interest in the discussion. 



Every one who proposes a new theory being bound to shew 

 that preceding ones are insufficient, I^.Ir Milne has entirely 

 set aside that of Mr Darwin. I should not, therefore, now 

 notice the theory of the latter gentleman, were it not to point 

 out that an objection he stated, unfounded, against mine, is 

 applicable to his own, though it has been received with nmch 

 favour by the English geologists ; and perhaps the ease with 

 which he rejects the theories of others, without taking the 

 trouble to disprove them, may have contributed to gain the 

 favour of those who are more accustomed to the simple effort 

 of describing facts, than to the more complicated one of ac- 

 counting for them. INIr Darwin appealed to Dr MacCulloch's 

 elaborate argument to shew that no sudden change could have 

 taken place in their formation ; and against the objection that, 

 as the shelves were separated from each other by considei'a- 

 ble distances, a sudden movement in the rising of the land 

 was necessary to the formation of each shelf, Mr Darwin af- 

 firmed that the force which acted upwai'ds pushed up only the 

 space occupied by the shelocs, and, of course, he imagines it to 

 have been so carefully regulated as to preserve them un- 

 broken. If the space including these shelves had been ex- 

 clusively elevated somewhere about 1300 feet above the level 

 of the sea, it is singular that I\Ir Darwin did not seek for, 

 find, and point out, the boundai'y of the elevated space, since 

 it ought to stand out clear of the surrounding country from 

 which it had been separated. One would imagine, that the 



