i88o-i88i.] 63 



mountains, most of which appear to be hollows ground out of 

 the solid rock. There are in addition a number of lakes which 

 have now become silted up, which in their position resemble 

 those that still remain. A map was shown exhibiting all the 

 ground in the district more than two thousand feet above the 

 sea, and it was pointed out how the lakes radiated out from this, 

 their upper ends invariably having a group of high mountains 

 around them. It was now generally admitted by geologists 

 that the whole district had either been filled up with large 

 glaciers which rose above the brim of the valleys, or else 

 entirely covered with a dome-shaped mass of ice, that spread 

 far out to sea, and joined with an ice sheet from Wales, Ireland, 

 and the South of Scotland. The lecturer then described a tour 

 through part of the district, starting from Windermere, the 

 islands in which appear as though ground to the water's edge 

 by some abrading force. Great and Little Langdale were then 

 described, and a survey taken from the summit of one of the 

 Langdale Pikes, which lie about the centre of the district. It 

 was shown on the map that at the head of each lake one or 

 more streams of ice from the mountains had united, and that 

 wherever this took place there would be caused an increased 

 flow; the narrowing of the valley, or the presence of an 

 obstacle, would also cause an additional pressure of the ice upon 

 its bed ; and in each of these spots was to be found either a 

 lake now in existence or one which had been silted up since the 

 glacial period. The same result, of immense pressure and more 

 or less rock excavation, would follow when the ice, after a 

 descent of one thousand or fifteen hundred feet, came upon a 

 more level bed. It is in such positions that the tarns generally 

 occur. Looking from the summit of Langdale Pike, 2,400 feet 

 above the sea, the hills, 800 feet lower, which enclose Langdale 

 on each side for miles, appear as if something had flowed over 

 them ; they are all ice-ground, in fact. A drawing was shown 

 of Side Pike, a hill exactly the height and size of Cave Hill, 

 over which the ice had gone bodily, rounding and smoothing it 

 to the very top. As a contrast to this, a view of the summit of 



