OF BARON HUMBOLDT. 35 



mer, in consequence of great drought and 

 heat, the vitality of the same must be pre- 

 served by artificial watering. Up to 58 deg. 

 latitude, Humboldt could, with tolerable cer- 

 tainty, determine the mean temperature of 

 these localities from the degrees of the heat in 

 the springs. More northward, the soil is from 

 12 to 15 feet deep always frozen ; whilst in 

 Norway, situated equally high, and higher 

 towards the North Pole, even in winter, grass 

 and moss are growing under the cover of the 

 snow. Humboldt had a well sunk in the midst 

 of summer, and encountered already, at a depth 

 of 6 feet, ice 9^ feet thick ; and it is a remark- 

 able phenomenon that, in spite of these subter- 

 ranean masses of ice, the short but powerful 

 heat of the sun during the summer months 

 rapidly causes the upper soil to thaw, assisting 

 in the production of an abundant harvest. The 

 subsequent results of this Asiatic journey of 

 Humboldt were of the greatest importance to 

 science. After he had left on many points of 

 Siberia, in the hands of experienced or able 

 men, carefully compared thermometers, and had 

 more especially awakened in the officers of the 

 Russian Government mines a zeal for such 

 mensurations and comparative examinations, 

 he urged the Imperial Academy of St. Peters- 



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