436 Scientific Intelligence. — Geology. 



on partly during winter, when, of course, the column of cold 

 air must have rushed into the pit and chilled the temperature, 

 it is probable that the spot at which the thermometer marked 

 the frozen point, was at the depth of 350 feet. This immense 

 thickness of ground ice would prove that Siberia must have 

 been for a long period in the same physical condition as it is at 

 present. In the actual state of our information on this subject, 

 it is impossible to determine how widely this layer of ground- 

 ice is spread under the surface of Siberia ; yet, we know enough 

 to say that it extends over an immense tract of country. Hum- 

 boldt found the soil frozen at a depth of 6 feet at Bosgolowsk, 

 near the Ural, in 60° North Lat. Near Beresow, Erman found 

 the temperature of the earth, at a depth of 23 feet, still + V.% 

 (351° F.), but in 1821 a dead body was disinterred, which had 

 been buried 92 years before ; the earth around it was frozen, 

 and the body did not shew any signs of decomposition. It 

 has long been known that at Obdorsk, in North Lat. 68°, the 

 ground is always frozen. Near Tobolsk no ice is found in the 

 soil, but as we proceed to the eastward, the ground ice ad- 

 vances farther north. It is to be hoped that measurements of 

 the temperature will shortly be made at different depths at 

 Yakutzk, and by methods which M. Schargin was unable to 

 employ ; also it is desirable to institute an inquiry as to the 

 depth at which the ice annually disappears near the surface, 

 and collect information on the depth of ground ice generally 

 in Siberia. It would also be highly gratifying to me, and ex- 

 tremely interesting to science in general, if the Geographical 

 Society of London would collect information respecting the 

 extent of the layer of ground ice in North America, the thick- 

 ness which it attains, and how much of it disappears by the 

 summer heat, in those countries over which the factories of the 

 Hudson's Bay Company are disseminated. At the termination 

 of the reading of this paper, an animated discussion took place 

 on the frozen soil o^ Siberia, in which the members stated their 

 views on the subject. It appears to be generally considered, 

 that the experiment at Yakutzk had not been made with suf- 

 ficient care, to authorize the belief that the frost penetrates to 

 so great a depth as 350 feet below the surface of the globe ; 

 also that the statements of M. Arago and Von Buch, and others 

 in our own country, on the increase of temperature in propor- 



