486 EDITOK'S NOTES. 



system of co-operative investigation which had its head- 

 quarters at Grottingen, there were others also which, 

 although they attracted less notice at the time, were not 

 less apparent upon a close examination of the simul- 

 taneous observations at distant stations. By a careful 

 examination of the diagrams in which these were repre- 

 sented in the Resultate aus den Beob. des magnetischen 

 Vereins, it could not fail to be perceived that (after due 

 allowance was made for the small differences at the 

 several stations of the absolute horizontal force of the 

 earth, which is the antagonistic of the disturbances), 

 the disturbing causes, whilst acting simultaneously, pro- 

 duced more extensive deflections at certain stations than 

 at others, indicating thereby that the energy of the dis- 

 turbing force itself was subject to variations due to un- 

 known peculiarities. Examples were not infrequent also, 

 in comparing the movements of the declination magnet 

 at two stations, of a difference in the proportional mag- 

 nitude of successive deflections, ona deflection being 

 greatest at the one station, and another deflection 

 greatest at the other station. Though almost always 

 exhibiting the same feature of simultaneity, the deflec- 

 tions showed considerable variety, and apparent irregu- 

 larity, in their extent. The conclusion seemed almost 

 unavoidable, and appears accordingly to have been 

 entertained by M. Gauss himself, that more disturbing 

 forces than one were contemporaneously in action ; that 

 these were, possibly, quite independent of each other, 

 and might have very different sources; their effects 

 being intermixed in very dissimilar proportions at places 

 differently situated in relation to the position and dis- 

 tance of their respective sources. The disentanglement 



