90 



most intens in the auroral max. belt. A declination needle 

 on the norlh side of the belt will be moved to the opposite 

 direction af a needle on the south side etc. As now the 

 stations, the observations of which have been compared, 

 are situated on opposite sides of the max. belt of auroras, 

 it is only natural that they must have opposite signs. 



8:0. In a paper, which is newly published in english 1), 

 it is shown by experiments that an electric current from the 

 air exercises an effect, highly favourable, on growing vege- 

 tables. Oar knowledge of the relatively rich vegetation in 

 the northern regions will conduce to assume an extraordi- 

 nary cause to its singalar activity and it is then natural to 

 ascribe it to the current from the atmosphere *). 



9:o From observations, with special small apparatus in 

 different hights, in Kultala and Sodankylä it seems probable 

 that the electric density from a certain value at the earth- 

 suriace decreases to a minimum at about 3 to 4 meter and 

 then begins to increase anew. 



From this short representation we must draw the con- 

 clusion that our researches and knowledge of the causes of 

 the magnetic variations or rather perturbations must be 

 imperfect, not to say impossible, without a thorough ex- 

 ploration of the earth-currents and the currents of the at- 

 mosphere över the whole globe. As the key to a solution 

 of these questions seems to lie in the polar-regions or rather 

 within and near the limits of the max. belt of the auroras, 

 it is highly desirable not to say necessary that the explora- 

 tions should be extended to this regions. 



*) In the. Electrical Keview. Xov. 14 th and 25 tli, and De- 

 cember 2 nd 16 tli, 1898. 



