Prof. Nordensldold — Former Climate of Polar Regions. 531 



found amongst the mountain masses that occupy the peninsula be- 

 tween Ice-fjord and Bell-sound in Spitzbergen, or in some parts of the 

 basalt region of north-western Greenland. In the interior of Ice- fjord 

 and at several other places on the coast of Spitzbergen, one meets 

 with indications either that the polar tracts were less completely 

 covered with ice during the Glacial era than is usually supposed, 

 or that, in conformity with Avhat has been observed in Switzerland, 

 inter-glacial periods have also occurred in the polar regions. In 

 some sand-beds not very much raised above the level of the sea one 

 may in fact find the large shells of a mussel (Mytilus ednlis) still 

 living in the waters encircling the Scandinavian coast. It is now 

 no longer found in the sea around Spitzbergen, having been probably 

 rooted out by the ice-masses constantly driven by the ocean currents 

 along the coasts. 



From what has been already stated, it appears that the animal 

 and vegetable relics found in the polar regions imbedded in strata 

 deposited in widely separated geological eras uniformly testify that 

 a warm climate has in former times prevailed over the whole globe. 

 From Palceontological science no support can be obtained for the assump- 

 tion of a periodical alternation of warm and cold climates on the sur- 

 face of the earth. 



A careful investigation of the structure of the different sedimentary 

 strata leads to the same result. We are now very well acquainted with 

 the origin and nature of the various strata, the substance of which 

 has been supplied by the destructive operation of glaciers on the 

 surrounding and subjacent mountain masses, and we can point out 

 certain marks by which these strata may be distinguished from 

 other non-glacial deposits. In these last, one very rarely meets 

 with any large stone boulders, which have fallen from some neigh- 

 bouring cliff, and been imbedded in sand or clay, either directly, 

 and, if so. close to the place where originally found, or else after 

 having in the spring been moved a greater or less distance by 

 river ice. In glacial formations, on the contrary, as one may 

 gather from the study of the strata in Scandinavia that belong to 

 the glacial period, erratic blocks transported on icebergs to far- 

 distant regions play an important part. If a climate similar to that 

 which now prevails in the arctic regions has several times during 

 various geological eras existed in the neighbourhood of the Pole, 

 one has reason to expect that sandstones inclosing large boulders 

 should often be met with in these tracts. 



But this is by no means the case, though such formations, if they 

 exist on a large scale, could hardly escape observation. 



The character of the coasts in the Arctic regions is especially 

 favourable to geological investigations. While the valleys are for 

 the most part filled with ice, the sides of the mountains in summer, 

 even in the 80th degree of latitude, and to a height of 1000 or 

 1500 ft. above the level of the sea, are almost wholly free from snow. 

 Nor are the rocks covered with any amount of vegetation worth 

 mentioning, and, moreover, the sides of the mountains on the shore 

 itself frequently present perpendicular sections, which everywhere 



