158 Dr. FoRCHHAMMER on Changes of Level 



On the Danish coast of the Sound, six miles to the north of Copenhagen, a 

 most decided beach occurs about six feet above the level of the present Sound, 

 and so completely out of the reach of the sea, that a range of houses has been 

 built between the ancient beach and the present shore. This renders it highly 

 probable that the level on the Danish coast changes in a proportion different 

 from that which takes place on the Swedish shore ; and this difference seems to 

 be connected with the fact, that the slight earthquakes which are felt in Sweden 

 almost every year are never experienced in Denmark, and that a shock of an 

 earthquake which in August 1829 was felt so strongly on the Danish coast of the 

 Sound, that the terrified fishermen in some places left their houses, was not at all 

 perceived on the opposite Swedish shores. 



I will, however, not dwell on these points, but proceed to detail my observations 

 on the island of Bornholm, the rocky base of which makes a change of level 

 more easily to be observed. The greater part of Bornholm consists of a granitic 

 rock, which forms the whole eastern shore of the island, and rising abruptly out 

 of the water, the sea is so deep that it generally allows large vessels to lie close 

 to the shore. To the height of 250 feet, the granite is covered by a stiff, loamy 

 soil ; but above that level nothing is found except barren gravel, the result of the 

 disintegration of the granite. The yellow loam everywhere contains fragments of 

 slates and transition limestones, the latter possessing the character by which they 

 are easily proved to have been transported from the island of Gothland. None of 

 the plutonic rocks, so common in our boulder formation, are to be found here ; 

 and by their absence and the frequent occurrence of the clay slates, which are 

 extremely rare in the boulder formation, this bed is proved to be of a different 

 origin. It is not a sea-beach, all the stones being completely mixed with the clay, 

 and on the west side of the granitic ridge no trace of it can be found. These 

 observations lead me to conclude that the bed of loam is the result of a violent 

 inundation breaking in from the north-eastern parts of the Baltic, the effect of 

 which may be seen everywhere, both in the form of the Danish shores and the 

 immense deposits of sand which cover a great part of Denmark, and which evi- 

 dently have been swept away from more easterly beds of the boulder formation. 





