PREFACE. XVII 



sides of the valley approach nearest (and almost without tak- 

 ing into account any of the other appearances equally conclu- 

 sive, although not quite so evident), without coming at once 

 to the conclusion, that some prodigious violence must have 

 been necessary to cause the present very singular and distort- 

 ed aspect of these strata that this violence must have pro- 

 ceeded from beneath that these rocks in this manner must 

 have been projected in a liquid form, as lavas and that thus 

 St Abb's is neither more nor less than an extinct volcano. 



" About a mile and a half south from St Abb's lies the vil- 

 lage of Coldingham, northward and westward from which ex- 

 tends the wide moor of the same name, consisting still of grey - 

 wacke, as far at least as can be determined from its loose rocks 

 and general outline, for few or no fixed rocks make their ap- 

 pearance. It is a wide and desolate region, but far from being 

 uninteresting, especially in cryptogamous botany. The most 

 striking object in this tract is Coldinghara Loch, a very curi- 

 ous and beautiful piece of water, about a mile and a half in 

 circumference, and occupying a very deep hollow in the hills. 

 Coldingham is about a mile distant from the sea, to whose 

 banks we shall again proceed, as it is there that the geology of 

 Berwickshire is both the most interesting and the most appa- 

 rent. Here, and for several miles, the coast appears to consist 

 of alternations of trap rocks, trap-tuff being the most abun- 

 dant, and the outline of the coast we find accordingly to be 

 considerably broken and rugged. This rock, very similar to 

 that forming the great central mass of Arthur's Seat, is parti- 

 cularly abundant a little to the north of Eyemouth. Very 

 near this, and forming the bold and projecting point named 

 the Fort, is a very singular and immense bed of conglomerate- 



