102 Ii. Chambers, Esq., on Glacial Phenomena in Scotland. 



and likewise many of the sky-lines, "both to the north and 

 south, — there was one fine group of examples. There is an- 

 other similarly striated or streaked surface only a few hun- 

 dred feet below the summit of the hill. The direction of 

 the striation in both instances is W. 30 N., being the general 

 direction of the ridge of which the mountain consists. About 

 800 feet below the summit, I found a block of granite, and 

 in several other places there were blocks of other rocks like- 

 wise different from those of which the hill consists. From 

 all I have seen, I can entertain no doubt that Schihallion owes 

 its form to a glacial agent which has engulfed its whole mass. 



It has been related that humps of brown moraine detritus 

 are found in the vale of the Tay, and in the tributary valley 

 which ascends to the skirts of Schihallion. Such is a general 

 condition of valleys in relation to similar mountain groups 

 in Scotland. On coming, however, to a col or summit-level 

 on the eastern skirts of the mountain (a place called "White 

 Bridge, fully 1000 feet above the sea), we find a total change 

 in the character of the detritus. Here we have the unmis- 

 takeable blue boulder clay, a deep bed, enclosing blocks of 

 various sizes, but none very large, all worn smooth and many 

 of them striated. This spot is a pass between valleys — 

 consequently lies out of the way of any common valley 

 glaciers, such as those which I believe to have deposited the 

 brown moraine matter just adverted to. It has been spared 

 by these glaciers, and allowed to retain its share of that other 

 covering elsewhere found so universal in Scotland. Such, at 

 least, is the only reading which I can give to the facts. 



In my former paper, I adverted to a peculiar mass of de- 

 tritus resting in the valley of passage at Dunmailraise. That 

 place, I said, had been out of the scope of the glaciers which 

 I showed must have once filled the valleys of the lake dis- 

 trict, and it had been allowed to retain a detritus probably 

 resulting from some earlier operations. By a second and 

 more careful observation, I have now satisfied myself that 

 this mass of detritus is greatly different from that composing 

 the remains of moraines at Grasmere, a point within the scope 

 of the valley glacier, descending to the east from the bosoms 

 of the Langdale Pikes. While both are fundamentally red 

 clays, and both of a compact character, the latter is less com- 



