RAMBLES OF A GEOLOGIST. 385 



mentary rock in the country, they had been formed of sun- 

 dried clay. " I brought," continued Mr Bremner, " one of 

 your itinerant geological lecturers to the spot, to get his opi- 

 nion ; but he could say nothing about the appearance : it was 

 not in his books." " I suspect," I replied, " the phenome- 

 non lies quite as much within your own province as within 

 that of the geological lecturer. It is in all probability an 

 illustration, on a large scale, of those floating forces with 

 which you operate on your foundered vessels, joined to the 

 forces, laterally exerted, by which you drag them towards 

 the shore. When the sea stood higher, or the land lower, 

 in the eras of the raised beaches, along what is now Caith- 

 ness, the abrupt mural precipices by which your coast here 

 is skirted must have secured a very considerable depth of 

 water up to the very edge of the land ; your coast-line must 

 have resembled the side of a mole or wharf: and in that 

 glacial period to which the thick deposit of boulder-clay 

 immediately over your harbour yonder belongs, icebergs of 

 very considerable size must not unfrequently have brushed the 

 brows of your precipices. An iceberg from eighty to a hun- 

 dred feet in thickness, and perhaps half a square mile in 

 area, could not, in this old state of things, have come in contact 

 with these cliffs without first catching the ground outside ; and 

 such an iceberg, propelled by a fierce storm from the north- 

 east, could not fail to lend the cliff with which it came in colli- 

 sion a tremendous blow. You will find that your shattered 

 precipice marks, in all probability, the scene of a collision of 

 this character : some hard-headed iceberg must have set itself 

 to run down the land, and got wrecked upon it for its pains." 

 My theory, though made somewhat in the dark, for I had 

 no opportunity of seeing the broken precipice until after my 

 return from Orkney, seemed to satisfy Mr Bremner ; nor, 

 on a careful survey of the phenomenon, the solution of which 

 it attempted, did I find occasion to modify or give it up. 



2 B 



