274 R. Chambers, Esq., on Glacial Phenomena 



one of exceeding value in the present disquisition, as it indi- 

 cates that at this particular period, the relative level of sea 

 and land, in our district at least, had been reduced from the 

 high point denoted in the preceding formation, down to one 

 not more than thirty feet above the present. It was a period, 

 in short, of extensive dry land. As might be expected, the 

 rivers had in this period worn out hollows in the solid struc- 

 ture of the country ; amongst other such cuttings was that 

 of the Water of Leith at the Dean, in our own neighbourhood. 

 So, at least, Mr Milne Home infers, and with good reason, 

 from finding on the sides of that hollow, a bed of the next 

 formation. 



This was a third boulder bed (No. 6), a drift of coarse 

 gravel, connected with the well-known erratics, which, how- 

 ever, are very generally superficial. This formation must 

 be regarded as, in our district, consequent upon a deep and 

 abrupt re-immersion, for it spreads up to elevations even 

 higher than the boulder clay. The long ridges of gravel, 

 called in Scotland kames, and identical in character with the 

 osar of Sweden, and eskers of Ireland, belong to this forma- 

 tion ; and the various ancient beaches which can be traced 

 from several hundred feet above the sea, down to its present 

 level, may be considered as the memorials of stages or pauses 

 in the subsequent and final emergence of the land. The 

 vegetable soil completes the entire series, being the product 

 of historic times. 



In the basin of the Clyde, there are some differences in the 

 suite of deposits, though the general harmony is sufficiently 

 clear. Mr John Craig describes the following series as ex- 

 isting at Glasgow : — 



( Sand under Trongate. 



4. < Laminated clays with recent marine shells ; newer 

 I portion containing only fresh-water shells, as physa. 



3. Boulder till. (What are below appear at Bell's Park.) 



2. Sand. 



1. Lower boulder till. 



The boulder till (No. 1), at Bell's Park, contains an abun- 

 dance of worn and striated boulders, and the subjacent sand- 

 stone exposed in making the Caledonian Railway Station 





