AURORAL SPECTRA 



AT DIFFKREM ALTITUDES AM) THF ORIGIN 

 OF THE GREEN AURORAL LL\E 



SECOND COMMUNICATION 



BY 



L. VEGARD 



WITH 2 FIGL'RES IN THE TEXT 



(ViDENSKAPSSELSKAPETS SkRIFTER. I. MaT.-NATURV. KlaSSE. I923. No. 9» 



UTGIT FOR FRIDTJOF NANSENS FOND 



CHRISTIANIA 



AT COMMISSION BV JACOB m'BWAD 



1923 



