1886 ] ON VARIATIONS OF CLIMATE IN THE COURSE OF TIME. 13 



oiie who sees them, there are other equally striking marks of 

 the old sea levels, viz. the so-called ..strandlinier'' o: shore-Unes. 

 which are known chie% through the researches of Prof. Mohu 

 and Dr. Karl Pettersen. 



When travelling through the fjords and sounds particularly 

 in Northern Norway, one sees here and there horizontal lines 

 drawn along the mountain sides sometimes several hundred feet 

 above the sea. They are not always equally marked, but appear 

 often remarkably clear; sometimes they look like roads or rail- 

 way lines. They are always horizontal, or nearly so, and must, 

 therefore, be remains of an old sea shore. Often two parallel 

 lines are seen running one above the other in the same place, 

 and on closer inspection it will be discovered that they are hol- 

 lowed out of the rock itself. They have a surface sometimes 

 many feet broad, and are bounded behind by a more or less 

 steep mountain wall, forming thus horizontal incisions in the 

 same. The shore-lines have also been brought to prove that the 

 rising was broken by periods of rest. during which the sea had 

 time to hollow out the rock; but I am of opinion that they could 

 be formed too under a gradual rising, if the climate be subjected 

 to periodical changes. The shore-lines belong to the northern 

 parts of the country and the deep fjords where the winter cold 

 is more severe, and they are found in districts where there 

 is a tide. They seem to have been blasted out by the influence 

 of the cold. At high tide the sea water fills the holes and 

 fissures in the rock, and when the tide recedes, it is left in the 

 same. In severe winters the water will freeze, and thus burst 

 the rock. During the rising of the land, shore-lines tvill he 

 hroJcen out in this manner, as long as the erosion is dble to Iceep 

 pace ivith the rising. When the climate becomes milder, a time 

 will come when the erosion is unable to continue. Then the 

 shore-lines will be lifted up above the level of the sea, and out 

 of the reach of the blasting influence of the water. If next, 

 after thousands of years, when the land has perhaps risen fifty 

 or a hundred feet, a period follows with a severer climate, a 

 new shore-line is formed below the former. 



