60 Prof. L. Yegard : Results of Northlight Investigations 



By means of the material collected at the Haldde Obser- 

 vatory, we were able to study in a more systematic way 

 than had been done before the distributions of luminosity 

 along the streamers. In order to characterize the luminosity 

 distribution we measured : — 



(1) The distance l x from the bottom edge to the place of 



maximum intensity. 



(2) The distance l 2 from the bottom edge to the point 



where the strong luminosity ceases. 



(3) The distance Z 3 from the bottom edge to the upper 

 limit of photographic impression. 



A statistical summary of the results is given in Table IX. 



Table IX. 







h 









l v 









*.. 





"3 

 > 



s 



a 

 m 



no 



p 



© 



p 



© 



>^ '- 

 P 



02 



.- 

 © 



p 



3 



15 

 EH 



0D 

 O 



< 

 O 



m 





 P 



O 



P 



I 





 EH 



> 

 1— 1 







co on 



P 



m 



CO 



P 



km. 



















0-5 







2-3 





5 





5 









... 



5-10 



■ • • 



.. .- 



3-4 





21 





21 











10-15 



1 





4-5 



2 



44 



2 



48 











15-20 



4 



... 



5-6 



3 



36 



6 



45 





1 





"i 



20-25 



13 





6-7 



16 



32 



14 



62 





2 





2 



25-30 



20 





7-8 



3 



17 



7 



27 





7 





7 



30-35 



22 





8-9 



1 



17 



5 



23 





7 





7 



35-40 



15 



"i 



9-10 





o 



3 



5 





13 



i 



14 



40-45 



21 



1 



10-11 





3 



1 



4 



3 



13 



1 



17 



45-50 



17 



4 



11-12 







1 



1 



9 



10 



1 



13 



50-55 



8 



5 



12-13 











2 



15 





17 



55-60 



9 



10 



13-14 







"i 



"i 



5 



7 



"2 



14 



60-65 



2 



2 



14-15 





' 1 



i 



2 



9 



5 



7 



21 



65-70 



9 



5 



15-16 











3 



3 



5 



11 



70-75 



2 



2 



16-17 







"3 



"3 



2 



5 



5 



12 



75-80 



4 



6 



17-18 







1 



1 



1 



6 



1 



8 



80-85 



1 



2 



18-19 











1 



4 



2 



7 



85-90 



4 



1 



19-20 







1 



i 





5 



1 



6 



90-95 



2 





20-21 







1 



1 





3 • 



1 



4 



95-100 



3 





21-22 













6 



1 



7 



100-105 



1 





22-23 















1 



1 



105-110 



3 



1 



23-24 







"1 



1 





"3 





3 



110-115 



1 





24-25 













1 





1 



115-120 







25-26 



















120-125 



"l 





26-27 



















125-130 





"l 



27-28 

























28-29 

























29-30 















1 



"l 









30-31 

























31-32 













1 





1 



... 





... 



Total 



. 25 



178 



48 



251 



28 



117 



30 



175 



Total.... 



.. 163 



44 



