REPORT OF MEETINGS FOR 1901 27 



near the roadside, whose scarped face revealed a layer of 

 Andesite lava. Soon after being thus reminded of ancient 

 volcanic fires, vre came in full view of North Berwick Law, 

 itself a volcanic hill, looking for all the world like another 

 Bass Rock, planted a short way inland, rearing its head 

 higher than its half-drowned brother, and having green-clad 

 lower slopes in place of steep cliff-sides battered by the salt 

 Firth. Both "Law" and "Bass" are identical in mode of 

 origin, each being in truth a " volcanic neck " consisting 

 of a hard trachyte, representing the solidified core in a volcanic 

 vent, whose crater, cone, and flanks have been denuded away ; 

 the last uprising lava having here consolidated, and with 

 adamantine endurance resisted later eons of denuding agencies. 

 Other Scottish hills owing their origin to hard igneous nuclei, 

 which have resisted denudation, are Traprain and Largo Law, 

 the Lomonds of Fife, the Castle Hill of Edinburgh, Arthur's 

 Seat, Stirling Hill, and Ailsa Craig. 



Arrived at Inngth at Canty Bay, and descending a steep 

 grassy slope to the shore, we began the embarkation. Fishing 

 boats were few and small, and naturalists many, and even 

 with the friendly arrival of Mr Dent's steamer, several voyages 

 to and fro, at intervals, were necessitated before the whole 

 company were upon the island. Those who were last to leave 

 the Bay had an opportunity of studying, with Mr Goodchild's 

 aid, the foreshore exposed by the ebbing tide, and this com- 

 pensated for their late arrival at the Bass Rock. The full 

 substance of what he intended to say is printed as an Appendix 

 here [p. 41], but was not, in its complete form, communicated 

 to the Club, owing to lack of time after our return from the 

 Rock. However, while waiting for boats, we had his verbal 

 explanation of some of the geological features presented 

 by this part of the coast. On the slab-like rocks of the 

 shore we examined with him the junction of the intrusive 

 Limburgite and the tuff, lavas which probably came from 

 Arthur's Seat or from North Berwick Law, old volcanic necks 

 which were once active volcanoes. The tuff is mixed with 

 other volcanic ejected matter, and includes within itself lapilli 

 and bombs, while the Limburgite closely resembles the com- 

 position of stony meteorites. An examination was made also 



