220 



C. F. GAUSS OX THE GENERAL THEORY OF 



in the above-mentioned Seventh Report of the British Associa- 

 tion/or the Advancement of Science. 



We are indebted for the great number of magnetic observations 

 in the Russian Empire, and in the neighbouring parts of China, 

 to 



Hansteen. (PoggendorfF's Annals.) 



Erman. {Reise urn die Erde, and manuscript communications.) 



Von Humboldt. {Voyage aux regions equinoxiales, T. 13.) 



Fuss. {Memoires de P Academic des Sciences de St. Peters- 

 bourg, Sixieme Serie.) 



Fedor. (Communicated in manuscript, through Struve). 



Reinke. {Observations Meteorologiques et Magnetiques, faites 

 dans Vet endue de I' Empire de Kussie, redigees par A. T. KupfFer, 

 Nr. II.) 



At the following places a mean has been taken of the determi- 

 nations of several observers. The differences between them are 

 sometimes greater than can be attributed to yearly changes. 



12. Tobolsk. 



Declination. 



IncUnation. 



Declination. 



IncHnation. 



Hansteen, 1828, . 

 Erman, 1828, . . 

 Fuss, 1830, . . 

 Fedor, 1833, . . 

 Erman, 1828, . . 

 Von Humboldt, 1829 

 Fuss, 1830, . . 

 Fedor, 1833, . . 



16. Catharinenburg 



Hansteen, 1828, . 



Erman, 1828, . . 



Reinke, 1836, . . 



Erman, 1828, . . 



Von Humboldt, 1829 



Fuss, 1830, . . 



Fedor, 1832, . . 



- 9° 58' 



- 9 47 



- 11 52 



- 10 20 

 . 71 7 

 . 70 56 



. 71 1 

 . 71 2 



- 6° 27' 



- 7 23 

 -55 

 . 69 24 

 . 69 6 

 . 69 19 

 . 69 15 



17. Tomsk. 



Declination. Hansteen, 1828, . . . — 8° 32' 

 Erman, 1829, .... - 8 36 



Inclination. Erman, 1829, 70 59 



Fuss, 1830, 70 51 



( 



