at Paris, Brussels, Gottingen, Berlin, and Stockholm, 5 



in which the temperature t is reckoned for the centigrade 

 thermometer. 



The following were the times of oscillation observed with 

 a chronometer.* 



Table of the Times of Oscillation of two Magnetic Needles at 

 Paris, Brussels, Gottingen, Berlin, and Stockholm. 



From these observations the horizontal intensities become 

 as follow : 

 Paris. 

 1-0000 



Mean 0-97109 



0-97831 



0-85648 

 By means of a dipping-needle of M. Gambey's, I find the 

 dip to be as follows: 



At Paris. . Berlin. Stockholm. 



67° 41' 68° 16' 71° 40' 



At Brussels, M. Quetelet had found the dip in the month 

 of May of 1831, to be 68° 49'. 



At Gottingen the dip has not been determined since 1S26; 

 but applying its annual decrease, it would be in 1832, = 

 68° 13'. 



