526 MUNICH MAGNETIC OBSERVATORY. 
is quite a characteristic circumstance, and appears to indicate 
that the magnetic variations of two places are not dependent on 
each other in the same way as if they were produced by the 
same current propagating itself through the earth. A better 
explanation of all the phenomena hitherto observed would be 
afforded by regarding the earth as a sphere, on the surface of 
which there exist an infinite number of isolated particles mag- 
netized by induction only. In such case the dependence of the 
magnetism of each particle on all the rest would be as if there 
subsisted a certain equilibrium; and that every change at any 
one point produces at other points a change, not of equal amount, 
but of such amount as would be requisite to restore the previous 
state of equilibrium. 
[In proof that a disturbance proceeding from a very distant 
source does not produce exactly the same movements at two 
stations but little removed from each other, Dr. Lamont sub- 
joins the observations made at Munich and at Hohenpeissenberg 
during the remarkable and widely-extended disturbance of the 
25th September 1841 ; he adds, that he does so also in compliance 
with the invitation contained in the circular letter of Mr. Airy, 
and expresses a hope that the interesting results to which these 
comparisons may lead may soon be discussed by that gentleman, 
noticing in the mean time that no similarity whatsoever can be 
traced throughout the Bavarian and the Greenwich observations 
made during the disturbance in question. 
In both the Munich and the Hohenpeissenberg observations, 
the changes of declination are expressed in angular value, and 
the changes of intensity are corrected for temperature, and are 
expressed in parts of the whole intensity. The observations at 
Hohenpeissenberg comprise only a portion of the duration of the 
disturbance of the 25th of September, to which portion the com- 
parison is necessarily limited. 'The memoir concludes with ob- 
servations of the absolute declination and absolute horizontal 
intensity on the Hohenpeissenberg, but these are unaccompanied 
by any remarks of general interest. | 
