502 J. G. Goodchild—On Drift. 



Where the general direction of glaciation within a small area is 

 known, it is often found, as was pointed out by Mr. James Geikie 

 in the ' Great Ice Age,' that the striae show that the ice was more or 

 less deflected on meeting with an obstacle, while the higher currents 

 moved in the general direction ; so that just above the obstacle the 

 ice must often have been flowing at right angles to that which was 

 passing the rock below. 



On the north-east side of Wastdale Crag, near the Granite Quarries, 

 a protuberant boss of the granite — about four feet by three in dia- 

 meter, and standing up like a short column about two feet above the 

 general surface near it — shows on the top striee ranging north- 

 easterly, or in the direction common in the immediate vicinity. 

 From the bottom of its most south-westerly part, that is to say 

 the point directly opposed to the current, the strise diverge upwards 

 in the form of a fan, winding spirally upwards round the sides until 

 they gradually merge into the main direction near the top. Along 

 the lee side, near the top, a small channel along a joint extends 

 in a direction at right angles to that of the top current, and although 

 it is only six inches below a part of the block showing well-marked 

 north-easterly striae, this tiny channel exhibited distinct glacial 

 scratches in the direction of its length, or exactly at right angles 

 to those just above it; so that in this instance the ice immediately 

 above the block must have crossed at least four distinct streams, 

 making with it every angle up to, or even beyond, a right angle. 



It is not easy to bring this home to the mind without the aid of a 

 diagram ; but some conception of the phenomena may be formed by 

 noticing the way in which the water of a river flowing over a 

 similar obstacle splits and passes round the block, pressing against 

 the sides, and closing in behind as a backwater ; while the direction 

 of the stream immediately above the diverging currents would remain 

 nearly unchanged. 



What has been stated of the small block of granite will apply 

 equally well to at least the greater part of the Fell of which it forms 

 a part. The recent operations of the Shap Granite Company have 

 laid bare many well -glaciated surfaces of the granite, which clearly 

 show that, whatever direction the ice may have had at high levels, 

 in the movements of its lower parts, it tended more or less to follow 

 the shape of the ground immediately beneath it, exactly as it did on 

 a smaller scale in the case of the rock just mentioned. It would be 

 easy to multiplj- such instances, as the ice seems everywhere, under 

 like circumstances, to have beliaved in a similar way. 



Where the body of the ice was impelled up the valleys, and many 

 instances of the kind could be adduced, there may sometimes be 

 found indications in the directions of the strioe. at high levels to 

 prove that the higher strata of the ice were acted upon by currents 

 flowing completely at right angles to the course of the lower parts, 

 so that from directions parallel with the length of the valley low 

 down the striae tend more and more to change into the direction of 

 the higher current as they are followed towards the hill tops on 

 each side. 



