VIEWS OF SCANDINAVIAN AUTHORS. 
555 
large portions of Siberia on the one hand, and Siluria on the other, may have been, 
like them, for ages the habitation of the great extinct quadrupeds. Such countries 
must, in all probability, have been as long above the sea as the low and drift- 
covered tracts of Europe were beneath it. 
P.S. — The allusion to Professor Forchhammer in the text (p. 541) does not do justice to his opinions, or suffi- 
ciently distinguish them from those of M. Sefstrdm. In a letter to Mr. Murchison, the former thus states his objections 
to the views of the latter “ When Sefstrdm first started his theory, the highest points that had been observed to 
be scratched were about 900 feet above the level of the sea, and the lowest a little below that level ; thus making about 
1000 feet of difference between the highest and lowest markings. That difference has now augmented by additional 
observations to more than 4000 feet. Hence Sefstrdm is obliged to imagine the motion of his flood to have been very 
quick, or otherwise the boulders could not have been suspended in the muddy mass. I had sufficient difficulty to 
imagine a stream 1000 feet deep ; but a current of 4000, moving with such a velocity that the boulders could not 
subside, is utterly beyond my power of conception. Again, when Sefstrdm first brought forth his views, all the 
worn sides which had been observed faced the north, and the supposition of a violent current from the Polar 
regions had some probability' in it. But Bohtlingk having shown, that such worn sides in the northernmost part 
of Scandinavia face to the south, whilst Siljestriim has observed the same phenomenon to the north of theDovref- 
jeld, we must now look for the origin of the current in the range of high lands or axis of the peninsula 1 . Now, 
whatever masses of ice (glaciers) imagination may heap up on the top and flanks of the Dovre and its prolongation, 
they certainly would not be sufficient on melting to move such a stream. Further, the distance from that chain to 
the south of Sweden (about 7° of latitude, the height of Sneehiitten, the loftiest mountain, being upwards of 8000 
feet) affords a mean declivity that seems to be quite inadequate to give velocity to a current such as is required to 
move boulders. Sefstrdm must also have supposed, that the numerous striated rocks which have a worn or weather 
side, and a lee or protected side, must originally have had the form of fig. a (see diagram overleaf), which by the 
action of the flood was changed to fig. b ; the part under the dotted line being washed away, which, considering 
the hardness of the Scandinavian granite, is an enormous demand. Besides, the first form seldom or ever occurs 
in (Scandinavian ?) rocks. Their original outline is most frequently a flattened ellipse, as represented in fig. c ; 
and their present shape (fig. d) would best be explained by the action of water on their steep or lee side, which, 
assisted by degradation arising from the jointed structure of the rocks, has removed the portion under the dotted 
line.” 
1 These decisive observations of M. Bohtlingk and M. Siljestriim respecting the form of the skars and the course 
which the detritus has absolutely taken to the north as well as to the south, are subversive of the theory' of M. Du- 
rocher, expressed in a memoir before alluded to, that the drift passed over Scandinavia from the Polar regions. We 
must not omit to state, that as early as the year 1828 (Ann. des Sci. Nat. vol. xiv. p. 6), our distinguished friend, 
M. Brongniart, when travelling with Baron Berzelius, observed the chief phienomenon of the striae on the rocks 
proceeding from north-east to south-west, and the parallelism of the Osars to that direction. To do justice, 
however, to all the authors who have written on this subject, we must refer our readers to a lucid summary of their 
works by Baron Berzelius, “ Jahres Bericht ueber die Fortschritte der Phys. Wiss.” 1844, p. 386. They will 
there find, that although Swedenborg, as far back as 1719, made some observations, Lasteyrie (Travels in Sweden 
and Norway, 1799 and 1800) gave the earliest clear ideas of the weather and lee side of the rocks. Sefstrdm first 
published in 1836. Nordenskiold has in the last year added some data from Russian Lapland to those col- 
lected by Bohtlingk, whose observations respecting the excentric shedding off of the blocks he has completely con- 
firmed. 
