Geological Society. 331 



angle obscure traces of strise and polished surfaces*. Some of these 

 effects may be imagined to have been produced by stones projecting 

 from the sides or bottom of floating masses of ice ; but it is impos- 

 sible. Dr. Buckland observes, to account by such agency for the polish 

 and striae on rocks at Blackford Hill, two miles south of Edinburgh, 

 pointed out to him by Lord Greenock in 1834. On the south face 

 of this hill, at the base of a nearly vertical cliff of trap, is a natural 

 vault, partly filled with gravel and sand, cemented by a recent infil- 

 tration of carbonate of lime. The sides and roof of the vault are 

 highly polished, and covered with strise, irregularly arranged with 

 respect to the whole surface, but in parallel groups over limited ex- 

 tents. These strise. Dr. Buckland says, cannot be referred to the 

 action of pebbles moved by water ; 1 st, because fragments of stone 

 set in motion by a fluid cannot produce such continuous parallel 

 lines ; and 2ndly, because if they could produce them, the lines woula 

 be parallel to the direction of the current : it is impossible, he adds, 

 to refer them to the effects of stones fixed in floating ice, as no such 

 masses could have come in contact with the roof of a low vault. On 

 the contrary, it is easy, he says, to explain the phsenomena of the 

 polish by the long-continued action of fragments of ice forced into 

 the cave laterally from the bottom of a glacier descending the valley, 

 on the margin of which the vault is placed ; and the irregular group- 

 ing of the parallel strise to the unequal motion of different fragments 

 of ice, charged with particles of stone firmly fixed in them, like the 

 teeth of a file. The cave is not three hundred feet above the level 

 of the sea, and the proving of glacial action at this point justifies, 

 the author states, the belief that glaciers may also at that period 

 have covered Calton Hill and the Castle Hills of Edinburgh and 

 Stirling. 



Dec. 2. — The second part of Dr. Buckland's Memoir on the Evi- 

 dence of Glaciers in Scotland and the North of England, was read. ' 



The first part of the Memoir concluded with an account of glacial 

 phsenomena in the neighbourhood of Edinburgh (see ante, p. 326) ; 

 and the line of country more particularly described in this portion 

 extends southward from Edinburgh by Berwick, Newcastle, the Che- 

 viots, the lake districts of Cumberland and Westmoreland, Kendal 

 and Lancaster, to Shap Fell. A large portion of the low lands be- 

 tween Edinburgh and Haddington is composed of till or unstratified 

 glacier-mud containing pebbles. In the valley of the North Tyne, 



* In October 1840, Mr. McLaren found a polished surface on a portion 

 of rock near the south-west base of Arthur's Seat. 



Dr. Buckland has in his possession lithographs copied from drawings made 

 by Mr. James Hall, of distinct west and east furrows which extend over a 

 portion of the north side of the summit of Calton Hill, and on the surface 

 of the carboniferous sandstone at Craig Leith Quarry. Dr. Buckland saw 

 similar dressings in 1824 in a sandstone quarry near the house of Lord Jef- 

 frey, two miles west of Edinburgh ; and in 1840, in a railway section at 

 Bangholm Bower, one mile north-east of Edinburgh, he found in stratified 

 till and sand manv striated and fluted boulders. 



