58 Geological Society. 



Leaving these scenes of paroxysmal violence, let us next inquire, 

 whether there may not be going on, in the calmest seasons and in 

 the stillest countries, a chronic and almost imperceptible impulsion of 

 land upwards. 



As early as the time of Swedenborg, who wrote in 1715, it was 

 observed that the level of the Baltic and German Ocean was on the 

 decline. About the middle of the last century an animated and 

 long-continued discussion took place in Sweden, first as to the cause 

 of this phenomenon, and then as to its reality. Hellant, of Tornea, 

 who had been assured of the fact by his father, an old boatman, and 

 who afterwards witnessed it himself, bequeathed all he had to the 

 Academy of Sciences, on condition that they should proceed with 

 the investigation : the sum was small, but the bequest answered the 

 purpose. Some of the members of the Academy made marks on 

 exposed cliffs and in sheltered bays, recording the day on which the 

 marks were made, and their then height above the water. The Baltic 

 affords great facility to those who conduct such experiments, as there 

 is no tide, nor any other circumstance to affect its level, except 

 unequal pressure of the atmosphere on its surface and on that of 

 the ocean : this produces a variation which is curiously exemplified 

 at Lake Malar near Stockholm. As the barometer rises or falls, the 

 Baltic will flow into the lake, or the lake into the Baltic. The va- 

 riation resulting from the inequality of atmospheric pressure, how- 

 ever, is trifling. In sheltered spots, mosses and lichens grow down 

 to the water's edge, and thus form a natural register of its level. 

 Upon this line of vegetation marks were fixed, which now stand in 

 many places two feet above the surface of the water. 



In the year 1820-1, Bruncrona visited the old marks, measured 

 the height of each above the line of vegetation, fixed new marks, 

 and made a Report to the Academy. With this Report has been pub- 

 lished an Appendix by Halestrom, containing an Account of Mea- 

 surements made by himself and others along the coast of Bothnia. 

 From these documents it would appear, 1. That along the whole 

 Coast of the Baltic the water is lower in respect to the land than it 

 used to be. 2. That the amount of variation is not uniform. Hence 

 it follows, that either the Sea and Land have both undergone a 

 change of level, or the Land only ; a change of level in the Sea only- 

 will not explain the phenomena. 



A quarter of a century has now elapsed since Mr. von Buch de- 

 clared his conviction that the surface of Sweden was slowly rising all 

 the way from Frederickshall to Abo, and added that the Rise might 

 probably extend into Russia. Of the truth of that doctrine the pre- 

 sumption is so strong, as to demand, that similar experiments and 

 observations should be instituted and continued for a series of years 

 in other countries, with a view to determine whether any change of 

 level is slowly taking place in those also. The British Association for 

 the Advancement of Science have already obeyed the call. A com- 

 mittee has been appointed to procure satisfactory data to determine 

 this question as far as relates to the coasts of Great Britain and Ire- 



