234 R. Chambers, Esq., on Glacial Phenomena 



cliff on the other side of the valley, but nevertheless contain 

 only masses of quartz derived from Canisp. 



The only other detrital phenomenon of the kind here ad- 

 verted to which I have to mention, is one in Glen Messan, a 

 branch of the greater valley, containing the Holy Loch, in 

 Argyleshire. Not far from the mouth of this glen, close 

 above a place called Coruisk, where another branch glen joins 

 it, there is a lofty mound of detrital matter, smooth in the 

 surface, and covered with turf, forming a sort of barrier 

 across the valley, but leaving an opening at the north ex- 

 tremity, through which runs the little river Messan. This, 

 1 suppose, is the moraine which Mr Maclaren introduced to 

 the notice of the British Association in 1850. I do not pre- 

 sume to decide about the actual history of this remarkable 

 and singular object, but would merely remark that some 

 caution will be necessary before deciding that it is the mo- 

 raine of a glacier which has descended Glen Messan, as, con- 

 sidering its relative situation, and remembering similar ob- 

 jects in the valleys of the Alps, it may be the left lateral 

 moraine of the glacier of the branch glen which issues into 

 Glen Messan close by. However this may be, there is an 

 example of the true moraine in Glen Messan, about the 

 origin of which there can be no mistake. It occurs at a place 

 called Stronlonaig, about three miles above Coruisk. There 

 is here a corry on the south side of the glen, a rude savage 

 recess, enlivened only by a tumbling torrent. In the bottom 

 of the glen, two short lines of moraine matter curve towards 

 the mouth of the corry, but at such a distance that no watery 

 action connected with the corry could account for them. 

 Besides, between the ridges and the mouth of the corry, there 

 is a talus of gravel, the separate and characteristic result of 

 such watery action, and evidently of later origin. In short, 

 there has first been a glacier in this corry, descending into 

 Glen Messan, and leaving there two terminal moraines in 

 succession ; afterwards, this has passed away, and been suc- 

 ceeded by the present system of things, during which the 

 rivulet has formed a talus of debris circumscribed by the 

 inner moraine. 



