THE GEOLOGIST. 



affords strong proof of the former occurrence of a frigid 

 climate in the temperate zone; viz. that the shells found by 

 Captain Bayfield, in a modern deposit near Quebec, belong 

 to arctic genera and species resembling those collected by 

 Mr. Lyell, at Uddevalla. in Sweden. Those also found by 

 Mr. Smith in the valley of the Clyde possess an arctic ap- 

 pearance. Although the discovery of arctic remains is at 

 present confined to temperate regions, there can be no doubt 

 that the distribution of boulders in the torrid zone was caused 

 by the same means as in the temperate one. 



The observations of these geologists appear to me to fur- 

 nish considerable data towards explaining the occurrence 

 of sea beaches at an elevation above the present sea level. 

 Although this, at first sight, may appear improbable, yet when 

 we connect the general distribution of glaciers with other cir- 

 cumstances, the inference will in a great measure be borne out. 



The general distribution of ice over the surface of the 

 earth would cause a great decrease in the temperature of the 

 waters of the ocean. These, deriving their heat from the 

 land, are affected by the changes which the temperature of 

 the earth undergoes ; in different latitudes partaking, at the 

 surface, of a temperature similar to that of the neighbouring 

 land : but the temperature of the sea, under the same lati- 

 tude, varies considerably with the depth ; in the tropical and 

 temperate regions, decreasing with an increase of depth; 

 while, in high latitudes, the reverse is the case; viz. an increase 

 of temperature without an increase of depth. Captain Labine, 

 in latitude O'* 33^ N. found the temperature at 653 fathoms 

 to be 43; that of the surface being 78J. Also Scoresby, in 

 latitude 78° 2' N. found the temperature at the depth of 761 

 fathoms to be 38 ; the surface being only 32.* 



* Some authors have stated, that the waters of the ocean are influenced 

 by heat in a similar manner with matter generally. But the above ex- 

 periments show, that salt water, as well as fresh, offers an anomaly to the 4 

 laws of cooling, so far, at least, as density is concerned. 



