14 TRANS. OF THE ACAD. OF SCIENCE. 



amiss to trace atmospheric as well as terrestrial electricity 

 to that higher source in the interior of our globe — terrestrial 

 magnetism. The astounding discoveries made during this cen- 

 tury, in the exploration of this power, rather favor this theory. 

 Atmospheric electricity, according to my view, is magneto- 

 electricity, emanating from the magnetic force of our globe 

 and manifesting itself either by regular magneto-electric cur- 

 rents from (magnetic) pole to pole, or by constant magneto- 

 electric induction of the atmosphere from the surface of the 

 entire earth. 



Terrestrial magnetism, in its three-fold manifestation of 

 intensity, inclination, and declination, has commanded pre- 

 eminent attention in this century, especially since the late 

 Alexander von Humboldt, whose favorite study it was, pre- 

 vailed upon England and Russia to erect, in the most distant 

 parts of their vast empires, magnetic observatories. By a 

 net-work of observations over the globe, great results have 

 been obtained ; two magnetic poles — the magnetic equator 

 and the four points of greatest intensity — have been ascer- 

 tained ; the isogonic, isoclinic, and isodynamic lines have 

 been laid down, and the daily and yearly periodical changes 

 in intensity, declination, and inclination have been deter- 

 mined. But for our purpose it will suffice to point out only 

 some of these results which may have a direct bearing on, 

 and relation to, atmospheric electricity. 



First. The magnetic needle exhibits daily four regular 

 motions ; as it were, a magnetic ebb and flow, corresponding 

 to the four periodical risings and falls (the two maxima and 

 two minima) of the barometer and the electrometer. 



Second. The magnetic force (intensity and inclination of 

 the magnetic needle) is greater in both the northern and south- 

 ern hemispheres in the months of December, January, and 

 February, when the sun is nearest the earth, than in those 

 of May, June, and July, when it is most distant from it. 

 Greater or less distance from the sun controls therefore the 

 magnetic force. Whereas, if these effects were due to the 

 temperature, the two hemispheres should be oppositely instead 

 of similarly affected at each of the two periods mentioned. 



Now atmospheric electricity, as diagram No. 3 shows, has 

 also its greatest intensity in December, January, and Februa- 

 ry, and is lowest from June to September. As this corres- 

 ponds merely to the inverse proportion of temperature, the 

 latter is assumed thus to influence the intensity of atmos- 

 pheric electricity. But, if experiments made in the southern 

 hemisphere should prove, that the greatest intensity of at- 

 mospheric electricity appears there in the same months as 

 in the north, it would follow conclusively, that not tempe- 

 rature, but magnetic force controls, in this respect, atmosphe- 

 ric electricity. In the interest of science, I take the liberty 



