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.dependent on the local hour only. Arrhenius has already given an 

 explanation of the nocturnal maximum. 



In recent times it has often been attempted to explain magnetic 

 fluctuations by the movement of electric charge through the higher 

 layers of the atmosphere. (Schuster, van Bezold, Schmidt, Bigelow). 



The remarkable analogies which are met with in many cases 

 between the streamfield of atmospherical circulations and the fields 

 of magnetic fluctuations, lead to such speculations. 



I believe it is allowed to hazard analogous speculations concerning 

 the cause of the beginning of impulse and postturbation. 



We may suppose the streams to contain negative electrons. When 

 they strike the earth the outer layers will be charged with negative 

 electricity. These outer layers do not rotate in 24 hours, but in a 

 longer time increasing with their height. 



So a countercurrent of E — W direction charged with negative 

 electrons will originate, causing an increase of H and a decrease 

 of Z. The electrons, however, on entering the magnetic field of the 

 earth, will follow the lines of force towards the magnetic south pole 

 (the positive pole). The movement of negative electrons along the 

 lines of force has been fairly well proved, as is well known, by the 

 aurorarays. 



By this movement, the current of electricity will become NE — SW 

 and a westerly deflecting S-impulse will be the consequence. 



The sudden charge of the extreme layers of the atmosphere with 

 negative electricity, Avill attract the positive ions, with which the 

 high layers may be supposed to be charged, to still higher layers. 



These positive ions will thus enter into a faster moving counter 

 current, and a positive charged counter current will be the conse- 

 quence. 



These ions will move along the lines of force towards the north, 

 but much slower than the negative electrons, and therefore the 

 resulting deflection of the magnetic force caused by such a -|- current 

 viz. a force contrary to the ordinary one, will be of no appreciable 

 magnitude. It is conceivable that the effect, which accordingly is in 

 the same sense as the postturbation, will develop in a more gradual 

 manner than the commencing impulse of the S-storms; moreover 

 we may understand that it disappears still more gradually in propor- 

 tion as the negative electrons again leave the earth or are neutralised 

 by positive ions. 



Only we should expect the current to follow the latitude-parallels 

 and accordingly the vectors of postturbation to point to the true 

 south and not to the soutiierly end of the earth's mean magnetic axis. 



