THE FROZEN SOIL. 43 



and of the coasts of the sea of Kara by Sujew, the whole of the 

 most northern part of Siberia was described by too hasty a 

 generalization as entirely devoid of vegetation, always frozen 

 on the surface, and covered with perpetual snow, even in the 

 plains. The extreme limit of vegetation in Northern Asia 

 is not, as was long assumed, in the parallel of 67, although 

 sea -winds and the neighbourhood of the Bay of Obi make 

 this estimate true for Obdorsk ; for in the valley of the 

 great River Lena, high trees grow as far north as the lati- 

 tude of 71. Even in the desolate islands of New Siberia, 

 large herds of reindeer and countless lemmings find an 

 adequate nourishment.** MiddendorfFs two Siberian expe- 

 ditions, which are distinguished by a spirit of keen observa- 

 tion, adventurous daring, and the greatest perseverance in a 

 laborious undertaking, were extended from the year 1843 to 

 1846 as far north as the Taymir land in 75 45' lat., and 

 south-east as far as the Upper Amoor and the Sea of Ocbotsk. 

 The former of these perilous undertakings led the learned 

 investigator into a hitherto unvisited region, whose explora- 

 tion was the more important in consequence of its being 

 situated at equal distances from the eastern and western 

 coasts of the old Continent. In addition to the distribution 

 of organisms in high northern latitudes, as depending mainly 

 upon climatic relations, it was directed by the St. Peters- 

 burgh Academy of Sciences that the accurate determination 

 of the temperature of the ground and of the thickness of the 

 subterranean frozen soil should be made the principal objects 

 of the expedition. Observations were made in borings and 

 mines at a depth of from 20 to 60 feet at more than twelve 

 points (near Turuchansk, on the Jenisei, and on the Lena) at 

 relative distances of from 1600 to 2000 geographical miles. 



The most important seat of these geothermic observations 

 was however Schergin's shaft at Jakutsk 62 2' N. lat. 45 



44 E. von Baer, in MiddendorfFs Reise in Sib., Bd. i, s. vii. 



45 The merchant Fedor Schergin, cashier to the Russian- American 

 Trading Company, began, in the year 1828, to dig a well in the court- 

 yard of a house belonging to the company. As he had only found 

 frozen earth and no water at the depth of 90 feet, which he reached in 

 1830, he determined to give up the attempt, until Admiral Wrangel, 

 who passed through Jakutsk on his way to Sitcha, in Russian America, 

 and who saw how interesting it would be, in a scientific point of view, 

 to penetrate through this subterranean stratum of ice, induced Schergin 



