250 K. Chambers, Esq., on Glacial Phenomena 



platform not connected with valleys, there are traces of an 

 independent and, I believe, earlier glaciation. On Cuineag 

 and Canisp — on the former np to the height of 1700 or 1800 

 feet, and on the latter not much less, the quartz surfaces are 

 marked with black streaking s\ which are the striae peculiar 

 to a singularly hard rock, and these run from about N. 60° 

 W. with certain exceptions. One of these is at the base of 

 the slope of Cuineag, where the streaks are from the direct 

 north, apparently by reason of the turn which the agent has 

 there received from the base of the adjacent hill. Another 

 exception is at the hollow dividing the mass of the hill from 

 its loftiest top, where another system of streakings comes 

 in from the direct west, thus with the other set clipping the 

 summit of the hill. It may be remarked that the dip of the 

 strata on the backs of these hills is usually at a somewhat 

 greater inclination than the outline of the surface, the resis- 

 tance having been the stronger the nearer the bottom. There 

 is a great quantity of quartz slabs strewed along the back of 

 the hill, being the last fragments which have been torn up 

 by the denuding agent, and many of the surfaces exposed 

 have evidently undergone no attrition. This has afforded us 

 an opportunity of observing the difference between an abra- 

 ded surface and one which has undergone no abrasion, and it 

 is very striking. The unabraded surface presents an inequa- 

 lity of outline, partaking of a tuberculated^character, which 

 is entirely wanting in one which has been subjected to the 

 striating agent. 



On a summit running south from Ben More, fully 1500 

 feet high, and four or five miles to the south-east of Cuineag, 

 there are streakings on the quartz, observing the normal di- 

 rection of this general movement, namely, about N. 60° W. 

 What is most curious and significant, and settles the question 

 of two systems and epochs of glaciation, is, the fact of there 

 being upon Canisp, cross stria) connected with those local 

 moraines at the base which were adverted to in the earlier 

 part of this paper. The strong normal streaks athwart the 

 hill from the north-west, a direction in which no local or limit- 

 ed mass of ice could move, are clearly chequered with fainter 

 streaks produced by this simple down-hill movement, which 



