Mr Hugh Miller on Boulder-Glaciation. 163 



been in the habit of giving to the glaciation of boulders 

 something of the attention that it is usual to bestow upon 

 the glaciation of rocks. My opportunities of observation 

 have chiefly lain inland among stream sections and railway 

 cuttings. I looked, therefore, not so much for boulder- 

 pavements as for parts of pavements or pavement-houlderSy 

 such as imperfect sections might reveal, and began to note 

 the glaciation of striated boulders in groups of five or ten, 

 and then in twos and threes, and ultimately, as experience 

 and data increased, singly. 



The general conclusion to which these observations has 

 led may be stated in a word. The larger boulders in the till, 

 quite irrespective of any a.rrangement in 'pavement form, are, in 

 favourable situations glaciated, if at all, in the direction of 

 ice-flow. 



Throughout the Border Counties of England, from the east 

 coast at Newcastle and Tynemouth to Carlisle and Silloth 

 upon the west, the evidence on the whole is uniformly 

 trustworthy and to the point. It cannot be said, of course, 

 that the larger boulders always bear striae. It is scarcely less 

 usual, however, to find the boulders striated in their place in 

 the till when the till is good than to find the rock glaciated 

 underneath. 



It is not necessary to enter in detail upon the glaciation 

 of the north of England. In general terms, Northumbrian 

 glaciation may be roughly divided into — (1.) general glacia- 

 tion, crossing the watershed from the west ; (2.) valley 

 glaciation, where the ice held with the valleys ; and (3.) 

 glaciation of the sea board, or along the coast from the north. 

 When the rock-strise and boulder- strise marking this glaciation 

 are set upon a chart side by side, and disting-uished by means 

 of different colours,^ the two kinds of evidence are seen to 

 agree in every detail. We are presented, in short, with two 

 modes of arriving at the same facts, one of which might 

 have been pursued if the country had been entirely drift- 

 covered and the rock-striae invisible. Both the boulder-striae 

 and the rock-striae occur practically at all levels from the 

 watershed to the coast. The highest-lying rock-striae are 



^ As was done in a chart exhibited when this paper was read. 



