4 On the S/ieloes of LuchaLer. 



ordinary natural cause. We see indications of great violence 

 in the rounding of lai'ge boulders, and in the reduction of 

 rock to the state of gravel and sand. To render his theory- 

 complete, Mr Milne should, perhaps, have instructed us 

 whence, and by what means, the loose materials were brought 

 to fill up the valleys. An appeal has no doubt been made to 

 oceanic currents. 1 am not, however, aware of any known 

 current that proceeds at such a rate as to enable it to carry 

 boulders and gravel along with it. An extraordinary force 

 appeai*ing requisite, its nature and origin should have been 

 explained, before its effects were assumed hypothetically. In 

 Mr Milne's paper, on page 410 of the 16th volume of the 

 Transactions of the Royal Society of Edinburgh, and page 

 355 of Jameson's Journal for July and October 1847, we 

 find him thus expressing himself: — "These facts, taken in 

 connection with the undoubted fact that detrital matter has 

 been spread over Scotland, to a height of at least 1500 feet 

 above the sea, pretty clearly indicate that detrital matter not 

 only may have been, but actually was spread over the Locli- 

 aber district, and filled its several valleys to the height of at 

 least the highest of the Glen-Roy shelves, thus affording am- 

 ple blockage for its lakes.'' 



"We have now an extensive mountainous district under the 

 sea, having its valleys filled with detritus to a specified ele- 

 vation. It is next to be raised out of the water by a process 

 so carefully managed, that the levels and parallelism of the 

 shelves, to be formed one after the other as the land rose, 

 were not to be distui'bed. Supposing the land elevated to 

 the height necessary to lay the surface of the detritus dry, 

 we have then a desert plain, extending some hundreds of 

 square miles. We may next suppose that water issued from 

 some points of the higher ground, to the amount of the 

 existing streams, and inquire to what quarter it was to 

 flow in order to join the sea ? According to the theory 

 under examination, the valleys were filled up with detritus 

 to the height of the highest shelf; consequently, there could 

 be no hollows for the formation of lakes, when the land was 

 raised so as to expose the surface of the detritus. Mr Milne 

 has not pointed out any limit to the detritus. The water, 



