Dr Richardson on the Frozen Soil of North America. 113 



■which had been buried ninety-two years in a bed of ground ice, shewing 

 no signs of decay ; and we learn from Belawski, that the lower parts of 

 the district are never without ice. So that Berezov is probably very near 

 the limit of perpetual ground ice ; for it is clear that peculiarities of soil 

 must have considerable influence in countries which lie near this limit. 

 Farther east this frozen soil extends much more to the southward. Georgi, 

 in the last century, related that ice remained in the ground throughout 

 the whole year, upon an island in Lat. 52° N., Long. 106° E., in the en- 

 virons of Lake Baikal." " In the district of Nertchinsk, Lat. 52°, the 

 ground thawed in summer from one to nine feet, according to its expo- 

 sure to the sun's rays, but beneath this the frost extended to the depth 

 of forty-two feet from the surface, when the intervention of solid rock 

 prevented farther search. On one occasion, Captain Frehse having dug 

 down six feet through the frozen ground, came to pure ice 1\ feet thick, 

 enclosing boulders of different rocks. Still farther east again, the perpe- 

 tual ground ice is found at a less depth southwards, probably because 

 the neighbourhood of the sea raises the temperature of the soil. Erman, 

 at least, found no ice at Okhotsk." (Baer, Geogr. Journ. vol. viii.) 



The observations on the temperature of the atmosphere in 

 North America hitherto recorded, and the course of the line 

 of termination of the forests towards its arctic extremity, in- 

 dicate that the isothermal lines dip, as in Siberia, to the south- 

 ward in their course from west to east through the continent, 

 and the reports of the frozen soil detailed below tend to the 

 same conclusion. Indeed, it has long been said that the cli- 

 mate of the north-west coast of America is milder and opener 

 than that of the eastern coast, and the difference of mean tem- 

 perature in the 57th parallel is stated by Raer to be 18° F.* 

 The observations of frozen soil made on opposite sides of 

 James's Bay are too few to found much upon, especially as 

 they are not supported by reports on the mean temperature 

 of the air, but they seem to denote a milder climate on the 

 east Bide of that bay than on the west. Were this proved to 

 be actually the case, it might be considered merely as another 

 example of the fact, that the western coasts of continents 

 have milder climates than the eastern ones, but it might also 

 he adduced in support of an explanation which I have else- 

 wheref endeavoured to give of the cause of the low tempera- 

 ture of the coast of Hudson's Bay, namely, the detention of 



* Vide Kichardson, Therm. Oh/. Geogr, Journ. vol. ix. p. 380. 



t Appendix to Franklin's Journey, and to Back's Joumoy in 18:W :;.".. 



VOL. XXX. NO. LIX. JANUARY 1841. H 



