A52 Miscellaneous Intelligence. 
it seems to rise in a revolving column, of which it is the base. We 
thus understand why the magnetic pole is always the apparent centre 
whence issues the light constituting the aurora borealis, or toward which 
it appears to converge. I shall not recur to the other circumstances 
which accompany this meteorological phenomenon, the agreement of 
which I have shown with the explanation I have given in @ letter ad- 
dressed to M. Arago, which was communicated to the is and 
inserted in the Philosophical Magazine for April, 1849, p. 286. : 
But, having referred to this letter, in which the question was also 
raised respecting the explanation of, the diurnal variations of the mag- 
netic needle, permit me to add, that I have had occasion to prove, In 
ngland, both by my own observations, and still better by the more 
extensive ones of several physicists,* the existence of electric currents 
having a direction from the northwest to the southeast on the surface of 
the fast ’ resence of these a can be eerily proved . 
Now, the temperature of the base of the column must vary 
with the season, with the time of the day, and with the latitude 
place where it is observed, but also with the nature of the surfé 
the globe on which it reposes. When, therefore, this we se is 
sea, the hours of maxima and minima of temperature are not the same 
i ol lea a 
Rip eeeapaeR@ ier emerge hetine gma. 9p Phil. Mag., Sew 
p. 344. - + Phil, Mag., vol. xxxiv, p. 466. 
e 
