604 Foreign and Miscellaneous Intelligence. 



Excess of observed Excess of observed 



length over the oscillations over the 



Stations. calculated length. calculated number. 



Ualan -f 0.00176 + 1.94 



Guahan 0.00:216 -2.38 



St. Helena +0.00069 +0,76 



Bonin + 0.00586 + 6.46 



London - 0.00246 - 2.71 



Valparaiso -0.00591 6.52 



St. Peter's and St. Paul's +0.00179 +1.97 



Sitka ...... 0.00117 - 1.29 



St. Petersburg!! . . . + 0.0016L +1.77 



With the exclusion of Valparaiso, which has a high southern alti- 

 tude, and the Bonin islands, the following result, which may be 

 assumed as correctly representing the observations in the northern 

 hemisphere, will be obtained, 



x = 39.023923; y = 0.192535; ellipticity = 



269 



The errors will then be as follows : 



Excess of observed 

 Stations. over calculated length. 



Ualan + 0.00205 



Guahan 0.00200 



St. Helena + 0.00093 



London 0.00262 



St. Peter's and St. Paul's . . + 0.00161 



Sitka - 000140 



St. Petersburg!! +0.00134 



The ellipticity here found nearly agrees with the mean results of 

 Captains Freycinet and Duperrey, but is greater than that determined 

 by Captain Sabine. 



The detailed description of the observations which Captain Luetke 

 intends to publish will contain the results obtained from a combina- 

 tion of these experiments with those of other travellers *. 



9. DIP OF THE MAGNETIC NEEDLE AT ST. PETERSBURGH. 



Observed by M. Hansteen in June, 1828 . . .71 17'. 3 

 By M. de Humboldt, (applying an instrumental correc- 

 tion) in May, 1829 . . . . ........ 71 14'. 5 



Ditto, in December, 1829 17 11'. 5 



By M. Kupffer in May, 1830 .... 71 IT. 3 

 It would appear from these observations, that the annual decrease 

 of the dip at St. Petersburg!! is about 3' f. 



10. ON THE DIRECTION AND INTENSITY OF THE MAGNETIC FORCE AT 



ST. PETERSBURGH. (M. Erman.) 



i. Variation of the Needle. The variation of the needle was. deter- 

 mined after the method first proposed by Professor Bessel, of Ko- 

 nigsberg, in Schumacher's Astron. Naclir., by means of a transit, 

 the telescope of which is exchanged for a compass, furnished with 

 * Petersburg!! Trans, 1830. f Ibid. 



