68 NOTES TO BOOK XII. 



that the Norwegian Storthing, or parliament, by a unani- 

 mous vote, provided funds for a magnetic expedition which 

 he was to conduct along the north of Europe and Asia ; 

 and this they did at the very time when they refused to 

 make a grant to the king for building a palace at Chris- 

 tiania. The expedition was made in 182830, and verified 

 Hansteen's anticipations as to the existence of a region of 

 magnetic convergence in Siberia, which he considered as 

 indicating a "pole" to the north of that country. M. 

 Erman also travelled round the earth at the same time, 

 making magnetic observations. 



About the same time another magnetical phenomenon 

 attracted attention. Besides the general motion of the 

 magnetic poles, and the diurnal movements of the needle, 

 it was found that small and irregular disturbances take 

 place in its position, which M. de Humboldt termed mag- 

 netic storms. And that which excited a strong interest on 

 this subject was the discovery that these magnetic storms, 

 seen only by philosophers who watch the needle with mi- 

 croscopic exactness, rage simultaneously over large tracts 

 of the surface of our globe. This was detected about 1825 

 by a comparison of the observations of M. Arago at Paris 

 with simultaneous observations of M. Kupffer at Kasan in 

 Russia, distant more than 47 degrees of longitude. 



At the instance of M. de Humboldt, the Imperial Aca- 

 demy of Russia adopted with zeal the prosecution of this 

 inquiry, and formed a chain of magnetic stations across 

 the whole of the Russian empire. Magnetic observations 

 were established at Petersburg and at Kasan, and corre- 

 sponding observations were made at Moscow, at Nicolaieff 

 in the Crimea, and Barnaoul and Nertchinsk in Siberia, at 

 Sitka in Russian America, and even at Pekin. To these 





