56 NATURAL HISTORY OF 



of their ancient amphibious visitors ; parts of the gulf, 

 which, half a century before had been crossed in boats 

 by the French academicians, were converted into per- 

 manent meadow land ; and more minute research dis- 

 closed, at a distance inland, successive lines of beach, 

 each provided with a bed of shells in a very recent 

 state. From these the sea had evidently receded, ac- 

 cording to the changes which an upheaving motion of 

 the land, proceeding from the north, effected on the 

 levels ; and correspondingly raised beaches have since 

 been observed by M. Bravais, on the opposite declivity 

 of the Lapland system, near Hamerfest and Cape North ; 

 which show, by being at greater elevations, the acting 

 forces to be most powerful on the Polar side. More 

 than a century passed with a view of settling the ques- 

 tion, by positive measurement, copper bolts were driven 

 in several rocks at the mean sea level, and subsequent 

 investigation substantiates, that the rising progress is 

 greatest in the north ; being at the summit of the Gulf 

 of Bothnia, at the rate of 4 feet in a century, decreas- 

 ing to one foot at Stockholm ; and, on the southern, or 

 German shore of the Baltic, at 0, or, as we think, de- 

 clining .* This supposition is countenanced by several 



* These researches date from the year 1700, when, to 

 mark the true level, copper bolts were driven in, and deep 

 grooves were cut in the rocks. They terminated in 182J ; 

 the observations being made by Davis, Hellant, Cydenius, 

 Klingius, Rudman, &c. Several French philosophers have 

 made later researches, and confirmed the progress. See 

 Hel. de Beaumont, Mem. Acad. des Sciences de Paris. 



