538 PEOF. T. m*e:. hughes on some 



Knot was split up along joints by the weather, and the ground covered 

 with a ruinous heap of broken rock, still in place or only just dis- 

 lodged, as may now be seen where the water gets into the joints 

 along the outcrop of the Silurian grit a little south of Crummack 

 farmhouse. 



A succession of heavy snowfalls, on the other hand, caused a 

 larger body of ice to rise against the western slopes of Kendal Eell, 

 to impinge on the northern end of Farleton Knot, to crowd into 

 Crummack Dale, and carry up and over the brow of the hill the 

 blocks loosened during the previous years when the glacier had 

 receded and left the surface bare. 



On Norber Brow this pushing-up hill of the boulders is more 

 marked ; for here the blocking of the mouth of the valley by the great 

 ridge of grit that runs across it by Whitestone Wood forced the ice 

 up to higher levels during the temporary advance of the glacier. It 

 had probably receded as far as the precipice at the head of Crum- 

 mack Dale, and the grit had been broken up by the frost and thaw 

 of many a season when the ice crept forward again. 



To sum up, then, it will appear that the simplest explanation of 

 the phenomena described is that the Pedestal Blocks of Cunswick 

 Tarn, of Farleton Knot, and of Norber Brow represent the last push 

 of the great glacier over some of the obstructions that lay in its 

 southward course. The glacier in its last advance picked up the 

 boulders due to the breaking up of massive beds exposed to the 

 action of frost and sun when the glacier had receded a little, and 

 pushed them forward a short distance. This was a process which 

 had probably been going on always at the end of the glacier, but it 

 was only here and there that local conditions allowed the record to 

 remain. 



No runlets could collect on bare jointed limestone, and therefore 

 there was no denudation except that due to the chemical and 

 mechanical action of the rain and other condensed atmospheric 

 moisture helped by vegetation. Where this was arrested by the 

 protecting boulder the limestone was preserved, while the sur- 

 rounding part perished, and thus the boulders stand on pedestals of 

 which they were themselves the cause. 



Discussion. 



The Peesident remarked upon the clear and terse way in which 

 the Author had placed his facts and arguments before the meeting. 

 At the same time he remarked that the case was open to be 

 regarded from two points of view. 



Prof. Peestwich said that a few years since he had been shown 

 some of these pedestal-perched blocks by Mr. Tiddeman, and that 

 he had come to a different conclusion from the Author upon the 

 question of their affording a test of age, as there seemed to be con- 

 siderable uniformity in their average height. He instanced the 

 case of surfaces exposed in old Roman quarries. He concluded 



