121 



any portion of the traps of Mull, Staffa, or the adjacent islets, were 

 poured out by a subaerial volcano ; and these the author considered 

 as placed almost beyond dispute, by the facts brought to light in 

 connection with the tertiary leaf-beds, overflown by lavas, at the 

 opposite headland of Ardtan, in Mull. 



4. Eecent Observations on the direction of the Striae on 

 Rocks and Boulders. By James Smith, Esq. 



Mr Smith of .Tordanhill next read a paper on the direction of 

 the striae on rocks and boulders in the West of Scotland. 



It had generally been supposed that the cause, whatever it was, 

 which lodged the erratic block beds in their present position had 

 proceeded from the north and west. 



This was true with respect to the basin of the Clyde and the east 

 coast of Scotland ; but on the western coast of Argyllshire, at Loch 

 Crinan and Appin he had observed that the strike side (stoss seite) of 

 the rocks pointed to the east, and the lee side (lee seite) to the 

 west, shewing that, in these cases, the direction of the moving force 

 was from east to west. Mr Hopkins' recent observations on the 

 direction from which boulders near Oban have been derived, shewed 

 that they also must have come in the same direction. 



Mr Smith then observed the occurrence of a large angular granite 

 block on the shore at Helensburgh, which apparently must have 

 been transported over ice. He had also observed at the Island of 

 Cumbra an angular mass of trap, resting on a scratched rock, and 

 split vertically into several pieces ; he had observed blocks split in 

 the same manner, which had fallen from the terminus of the glacier 

 of Grindelwald. 



The following Donations to the Library vi^ere announced : — 

 Philosophical Transactions of the Royal Society of London. 1851. 



Part 2. 4to. 

 List of Fellows of Do. 30th Nov. 1851. 4to. — From the Society. 

 Memoirs of the Royal Astronomical Society. Vol. XX. 4to. 

 Notices of Do. Vol. II. 1850-1. Nos. 1-9. 8vo.— i^rom the 



Society. 

 Quarterly Journal of the Geological Society. Vol. VIII., Part 1 . 



8vo. — From the Society. 



VOL. III. K 



