222 C. F. GAUSS ON THE GENERAL THEORY OF 



supplied by Captains King and Fitz Roy, and are taken from a 

 Kttle work by Sabine, [Magnetic Observations made during the 

 Voyages ofH. B. M.'s Ships Adventure and Beagle, 1826-1836.) 

 The determinations for the several other stations are taken 

 partly fi-om the above-named soiirces, and partly from the 

 following : 



1. Spitzbergen. Observer, Sabine, 1823. (From his Account 

 of Experiments to determine the Figure of the Earth.) 



2. Hammerfest. The declination and incUnation are the 

 means of the determinations of Sabine, 1823 {Pendulum Expe- 

 riments) ; and of Parry, 1827. {Narrative of an Attempt to reach 

 the North Pole.) 



3. Magnetic Pole, from Captain James Ross, 1831. {Phil. 

 Trans. 1834.) 



4. Reikiavik, from observations by Lottin, 1836, {Voyage en 

 Islande.) 



28. Berlin, from Encke, 1836. {Astronomisches Jahrbuch, 

 1839.) 



38. Gbttingen. The declination is for October 1, 1835 {Re- 

 sultate fur 1836, page 39) ; the inclination is reduced to the 

 same epoch by interpolation between von Humboldt's observation 

 in 1826, and Forbes' in 1837. 



39. London, from observations communicated in manuscript. 

 The declination, by Captain James Ross, for the mean epoch, 

 April, 1838 ; and the inclination by Phillips, Fox, Ross, Johnson, 

 and Sabine, for the mean epoch of May, 1838. 



48. Paris, for 1835, from the Annuaire for 1836. 



54. Milan, 1837, by Kreil. Communicated by him in ma- 

 nuscript. 



58. Naples, from observations by Sartorius and Listing. 

 The intensity, which was detemiined according to absolute mea- , 

 sure, has been reduced to the common unity, by the application 

 of the factor given in Article 31. 



64. Madras, 1837, from observations by Taylor, taken fromi 

 the Journal of the Asiatic Society of Bengal, May, 1837- 



30. 

 In judging of the differences between calculation and observa- 

 tion, as shown in the foregoing tabular comparison, it must be 

 remembered, on the one hand, that almost all the observations are 

 charged both with the errors of observation, and with the influ- 



