314 



C. F. GAUSS ON THE GENERAL THEORY OF 



The observations at Stockholm were made by Rudberg ; those 

 of intensity and inclination in 1832, and those of declination 

 in 1833 : Poggendorff's Annals, vol. xxxvii. The observations 

 at Brussels are for 1832 ; those of declination and inclination 

 are by Quetelet, [Bulletin de I'Academie de Bruxelles, tome vi.,) 

 those of intensity by Rudberg, [Sabine, Report on the Variations 

 of the Magnetic Intensity). I am indebted to the obliging com- 

 munication of Major Sabine for the determinations at the other 

 six new stations, as well as for the intensity at Callao, and for a 

 more recent determination of the dip at that place. The obser- 

 vations at Lerwick and Valencia were made by Captain James 

 Ross in 1838; those at Port Etches, Panama and Oahu, by 

 Captain Belcher in 1837 ; and those at Callao by the same 

 officer in 1838 : the inclination and intensity at Montreal were 

 observed by Major Estcourt in 1838; the declination at that 

 station is for 1834, but the observer is not named. 



There are two other trifling corrections to be made in the 

 table of comparisons. By an error of the press, the longitude 

 of Naples is made 10' too small, although the true longitude 

 14° 16', was employed in the calculation. 



The declination observed by FitzRoy at Otaheite is printed in 

 one part of the Magnetic Observations made during the Voyages 

 of H. B. M.'s ships Adventure and Beagle as 7° ^4' E., in an- 

 other part of the same work 7° 54' E. Of these two numbers, 

 the one employed in the table of comparisons was the erroneous 

 one ; the difference between calculation and observation at that 

 station is therefore + 2° 0-9'. 



The following errors of the press are also to be corrected : — • 



Page 186, line the last, /or twelve read fourteen. 



