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rare instances, have not survived the events that followed. What- 

 ever happened, I feel certain that it was during this earlier period 

 of large confluent glaciers that most of the preglacially-weathered 

 rock material was detached from the parent masses and transported 

 downhill and seawards by the ice. And it is but another way of 

 stating the same fact to observe that it must have been during this 

 prolonged period of intense local glaciation, and not at the ac ual 

 climax of the Glacial Period, that the largest amount of local 

 glaciation was effected. The main direction of the great glacial 

 furrows above mentioned is often nearly at right angles to the line 

 of movement of the ice when at its maximum of development. 

 This is clearly shewn by the strife, which, necessarily, mark the 

 direction of the very last movement of the sole of the ice at that 

 particular spot. In the Yorkshire Dales, and in the great mountain 

 mass lying between the Cross Fell Escarpment and the Tyne 

 Valley the prevailing movements of the chief masses of ice seem 

 to have been, all through, mainly downhill and seaward. And that 

 was the case even when the rigour of the climate had increased to 

 such an extent that the surface formed by the confluent glaciers of 

 those parts had risen to the highest level of the mountain tops. 



Southward Advance of the Scottish Ice. — But in some areas 

 adjoining the uplands just mentioned another factor came into 

 action at a late period in the glacial history of the North, and 

 altered the sequence of events very materially. Preglacially- 

 weathered detritus had been swept outwards and seawards from the 

 mountain areas around the Solway, probably in large quantities, 

 and much of this, as the icy flood swept southwards with increasing 

 force, may have been thrust outwards from the Solway into the 

 Irish Sea. But with the further advance of the ice, came a time 

 when the Scottish glaciers from north of the Solway began to join 

 ends with those extending northwards and north-westwards from 

 Cumberland. Then, as the outflow by way of the North Channel 

 became dammed up by the south-easterly advance of the Great 

 Northern Barrier, (whose upper surface must have been at least 

 2600 feet above sea level,) the only lines of movement open to the 



