ON THE MAGNETIC DISTURBANCES. 485 



II. On the Magnetic Disturbances. 



THE term-observations of the Grermaii Magnetic Asso- 

 ciation, superintended by MM. Gauss and Weber in 

 1835 and the following years, had shown that the 

 occasional and apparently irregular disturbances of the 

 declination magnet (to which element the German 

 term-observations were principally confined) took place 

 almost always contemporaneously, over the large portion 

 of the interior of the European continent comprehended 

 by their stations; and the numerous and rapidly vary- 

 ing fluctuations in the direction of the magnet which 

 were observed to take place during a disturbance at one 

 station, were found to occur simultaneously at other 

 stations with an accordance admitting of no mistake. 

 These facts, established by multiplied observations, gave 

 a great increase to the interest with which the minor 

 magnetic variations had been previously regarded, and 

 caused a general desire to be felt that the investigation 

 should be extended to more distant parts of the globe ; 

 and that, in particular, the questions of the contem- 

 poraneous occurrence of the disturbances, and the simul- 

 taneity of the fluctuations which they occasioned, should 

 be examined over a wider field than that of the German 

 Association, and should embrace different continents 

 and different hemispheres. 



But whilst the public attention was chiefly fixed on 

 what were undoubtedly the most prominent and the 

 most striking conclusions established by the extensive 



