( 416 ) 

 SCIENTIFIC INTELLIGENCE. 



METEOROLOGY. 



1. Temperature of the Globe in the Polar Regions and upon 

 the tops of Lofty Moimtarns. — In our climates the mean 

 temperature of caves, wells, and common springs, very nearly 

 corresponds with the mean temperature of the place where they 

 are situated, as determined by the thermometer placed in the 

 shade in the open air. This, however, no longer holds true in 

 certain countries near the pole, and in all places near the limit 

 of perpetual snow. There, as the observations of Messrs Wall- 

 lenberg and Leopold de Bitch have especially proved, the tem- 

 perature of the soil, and consequently the temperature of the 

 springs, are notably higher than the mean temperature of the 

 atmosphere. 



This anomaly had been explained in a manner which was 

 apparently satisfactory. The thick bed of snow which, in the 

 northern regions, or in those whose height above the horizon is 

 considerable, covering the soil during a considerable part of 

 the year, cannot fail, it is said, on account of its small conduct- 

 ing power, to prevent the extreme cold of winter from pene- 

 trating into the earth, or at all events from propagating itself 

 there to such depths as it would have reached, if the surface had 

 not been covered over with such an envelope. The snow, in 

 short, however strange the result may at first appear, is, all 

 things considered, a cause of real heating in those regions where 

 it remains for a long time. 



Can any thing, it may be inquired, be opposed to an ex- 

 planation so rational and evident ? There may. For first, 

 there is a great want of express specification. And again, 

 since the recent epoch when M. Erman communicated to the 

 Academy, his concordant comparative observations concerning 

 the temperature of the air and of the earth, made in Siberia, 

 we have, moreover, to oppose to the same explanation, that it 

 leads, as a matter of necessity, to differences of sensible caloric 

 for places where no such difi^erences exist, as, for example, at 

 Yakutsk, as we have lately learned. Those of the Scientific Com- 

 mission who propose to winter near the northern extremity of Eu- 

 rope, may hope, therefore, to resolve an important problem in 



