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beaches. These beaches sometimes contain sea-shells, which belong 

 partly to arctic species. 



In the great majority of instances these terraces are horizontal ; 

 and when that is the case, and more than one of these terraces form 

 continuous lines in the same district, they are all of course parallel 

 to one another. Brongniart, in the year 1829, was the first to call 

 attention to terraces of this description, the origin of which he attri- 

 buted to the subsidence of the waters of the ocean. This supposition 

 has by some geologists been considered as at variance with physical 

 probabilities ; and the more generally received hypothesis now is, 

 that these terraces owe their present position to elevation by subter- 

 ranean agency. 



This explanation at first sight appears very probable ; and the 

 more so as there are some ancient beaches which are not horizontal 

 but are inclined to the horizon. Of this description are the two 

 observed in Norway, between the 70th and 71st degrees of north 

 latitude, by Mons. Bravais ; of which the upper descends from its 

 summit level of 222 feet above the sea to its lowest level of 94 feet ; 

 and the lower descends from its summit level of 9 1 feet to its lowest 

 level of 46 feet. The present position of these Norwegian beaches is 

 probably owing to the same cause which has raised, and still con- 

 tinues to raise, a part of the Scandinavian peninsula above the level 

 of the ocean, and which has given rise to the ancient sea-beaches in 

 Sweden. It appears, however, from the discovery of a human ha- 

 bitation in connexion with these beaches in Sweden, that they be- 

 long, not to the post-tertiary, but to the historical epoch ; and it is 

 to the latter epoch, therefore, that we ought to refer the inclined 

 beaches observed in Norway by M. Bravais. 



The fact that the post-tertiary sea-beaches are, in the great ma- 

 jority of instances, horizontal, strongly militates against the notion 

 that they owe their present position to elevation from beneath ; as 

 does also the fact of their wide-spread geographical distribution, 

 which is so extensive indeed as to be almost universal. Were we to 

 admit that wherever these beaches are found the land has been ele- 

 vated, we must admit that in the post-tertiary period the elevating 

 of the land was almost universal ; a conclusion in itself so impro- 

 bable, that we ought to seek to explain the difference of level between 

 the post-tertiary beaches and the present ocean in some other manner. 



The author then propounds a new theory to account for the post- 

 tertiary horizontal sea-beaches. This theory he bases on the above 

 stated conclusion, derived from the appearances which the diluvium 

 and the alpine boulders present ; namely, that during the post-ter- 

 tiaiy period the temperature of the earth was lower than it is at pre- 

 sent. From the observations of Kotzebue, Sabine and Scoresby, he 

 infers, that at the depth of about 800 fathoms from the surface the 

 temperature of sea water, whether near the equator or in high 

 latitudes, is not very remote from 40 degrees of Fahrenheit, the point 

 of temperature at which the density of fresh water is the greatest : 

 and as the mean depth, according to Laplace, of the Pacific Ocean 

 is about four miles, and of the Atlantic about three miles, and the 



