99 



that they did not see the same phenomenon. They saw 

 a luminous space which for the one was projected on the 

 sky in one way and for the other in a different way. 



Our opinion is that the northlight can occur on a height 

 ofseveral 10 km, but also descend to near the earth-surface *). 



The difficulties which in general will meet these rese- 

 arches make it impossible for a private enterprise and it 

 seems as that the international Conference for the earth- 

 magnetism and the atmospheric-electricity is the natural me- 

 dium through which these important researches must be 

 furthered. We have therefore taken the liberty to propose 

 the conference to take these researches in consideration and 

 put on the program for a following meeting the questions: 



,,What signification must be attributed to the earth- 

 currents and the electric currents from the atmosphere in 

 the explanations of the causes of magnetic perturbations?" 



„What is to be done for the further investigation of 

 the connexion between the magnetic perturbations and these 

 electric currents?" 



The author proposes the establishing of two interna- 

 tional polar-stations, one in the North of America the other 

 in the North of Europé situated in the southern börder of 

 the polar-light maximum belt, both connected with northern 

 by-stations and rally equipped for all meteorological and 

 magnetical observations and for investigations of the earth- 

 current and the electric current from the atmosphere. 



*) This question has been the object of wide researches by Cle- 

 veland-Abbe in Washington, whereby he coraes to tbe result that all 

 ancient determinations of the beight are very doubtful or erroneous, 

 because two observers at different stations never observe the same phe- 

 nomenon. Terrestr. Magn. vol. III 1898. See also S. Lemström : L'Au- 

 rore boréale. Paris Gauthier-Villars 1886 p. 45 et. sniv. • 



