140 



up to 3G0 feet? Bat this is not all. There are terraces covered by 

 the sea. This introduces to us a new element in the computation, 

 namely, that the movements have been downwards as well as upwards, 

 and increases indefinitely the already almost inconceivable vastness of 

 the time necessary for these processes ; and yet this is but the modern 

 period, and in reference to the preceding eras of geology, may be said 

 to be but of yesterday. 



In reference to tliis point, Mr. Smith, of Jordan Hill, has made the 

 following remarks : — 



"At an elevation of about foi*ty feet, there has been observed upon 

 many parts of our coasts a series of raised beaches and terraces, which, 

 by their magnitude, indicate the prodigious length of time at which 

 the sea-level must have been stationary at this height ; and if we may 

 judge of its duration by the relative size of the ancient terraces with 

 those now forming, it must have exceeded the recent period, of which 

 3,000 years is but a part by an immense amount. But this is but one 

 of the epochs in the history of this formation. Between the gi'eat 

 terrace and the sea, several subordinate ones and beaches have been 

 observed, each of them marking long continued periods of repose ; 

 whilst a sudden deepening, two or three fathoms below low water-mark, 

 is probably caused by another line of terraces, now covered by the sea." 



The following table of the classification of the different formations of 

 this, the pleistocene or glacial period of geology, is constructed from 

 Mr. Smith's papers, and may help us to form an idea, or rather to lose 

 ourselves iu the attempt to form an idea of the extent of time necessary 

 for its production. 



1. Elevated marine beds. Ancient beaches. 



2. Submai'ine forests. 



3. Alluvial beds, most likely marine, but affording as yet no 



organic remains. 



4. Upper Diluvium or Till. The most recent deposit of the Till. 



Has yielded bones of the fossil elephant, and water worn 

 shells. " Cyprina Islandica," " A balanus," &c. 



5. Marine beds in the Till, affording shells. Occurs at Airdrie 



500 feet above the sea level. A bed of " Tellina proxima." 

 In site under No. 4, and above No. 6. 



6. Lower Diluvium, Till, or Boulder Clay. 



7. Stratified Alluvium, consisting of sands, gravels, and clays, 



without organic remains. Resting in the Clyde district, 

 immediately upon the upper members of the carboniferous 

 system. 



