SIMMONS— EVIDENCE OE GLACIAL ACTION IN SCOTLAND. 1G5 



evidences of such a movement, which must have taken place in the 

 period when the climate was colder than at present, and which, if not 

 paroxysmal, was sufficiently rapid to have entombed alive the testa- 

 ceous inhabitants of the sea, and to have covered them up to a con- 

 siderable depth with beds of finely laminated clay, which could only 

 have been formed at the bottom of the sea." The current or rush of 

 water made the ice bearing the erratics cut and polish the sandstone 

 in the neighbourhood. This rush of water was doubtless produced 

 by one of those earthquake waves thus described by Mr. Smith in 

 the above-mentioned work, and considered by him to be the force 

 that originated the till or boulder clay : — "A rush of water, such as 

 that produced by earthquake waves, of sufficient violence to tear up, 

 not only the pre-existing unconsolidated cover, but considerable por- 

 tions of the subjacent rocks, and perhaps obliterate the inequalities 

 caused by disturbances in the coal measures, passed over the island 

 from west to east, or, rather, from the north-west, depositing the 

 whole in a confused mass on the surface. In that part which was 

 under the sea, beds of gravel, sand, and clay were deposited. In 

 process of time, a second debacle swept over the island in the same 

 direction, but witli much less violence than the first; the stratified 

 beds, perhaps of no great thickness, were swept away, leaving, how- 

 ever, occasional patches sufficient to attest their existence, and also 

 part of the pre-existing diluvium, reducing the inequalities and 

 grinding the exposed surfaces of the rocks and boulders, for it is to 

 i his second debacle I ascribe the scratching of the rocks and boulders; 

 and here, 1 think, ice acted an important part, and was probably the 

 principal agent in grinding down the substance over which it passed. 

 A colder climate and a north-west direction both point to a frozen 

 ocean, which was perhaps broken up by the convulsion which caused 

 the diluvial wave, and the ice of which was swept over the land in 

 the Mime direction." Antiquaries formerly imagined the erratics, 

 or the boulders termed rocking stones, to be the workmanship ot 

 human hands; now however, Mr. Wright, one of the most talented 

 of their number, asserts that they are the result of natural causes. 

 Geology has proved tins ; and the same science lias also taken from 

 the territory of arclueology some of the stones said to be complete 

 cromlechs, the Lifts being an instance. 



When examining the boulders 

 near Loch Ken in Kircudbright- 

 shire, I observed among many of 

 great size and gigantic in composi- 

 tion, one 10 feet in height, and L3 

 feet 9 inches long, resting on two 

 small boulders, prismatic in form. 

 (Seesketch.) Workmen were blast- 

 ing some of the boulders when I was measuring, consequently their 

 number is decreasing ; and the evidence ol glacial action in the neigh- 

 bourhood of Loch Ken, as far as boulders ai r concerned, w ill soon cease 

 to exist. This, however, cannot be said of the striking glacial action 



Boulder near Loch Km. 



