XL] 
THE AUKORA A PERMANENT PHENOMENON. 
37 
other hand only had opportunities of registering single auroras; 
the phenomenon in the case of their winterings has not formed 
any distinctive trait of the Polar winter night. It was the less 
to he expected that the Vega expedition would form an excep¬ 
tion in this respect, as its voyage happened during one of the 
years of which we knew beforehand that it would be a mini¬ 
mum aurora year. It was just this circumstance, however, 
which permitted me to study, in a region admirably suited for 
the purpose, a portion of this natural phenomenon under un¬ 
commonly favourable circumstances. For the luminous arcs, 
which even in Scandinavia generally form starting-points for the 
radiant auroras, have here exhibited 'themselves undimmed by 
the more splendid forms of the aurora. I have thus, undisturbed 
by subsidiary phenomena, been able to devote myself to the 
collection of contributions towards the ascertaining of the posi¬ 
tion of these luminous arcs, and I believe that I have in this 
way come to some very remarkable conclusions, which have been 
developed in detail in a separate paper printed in The Scien¬ 
tific Work of the Vega Expedition (Part I. p. 400). Here 
space permits me only to make the following statement. 
The appearance of the aurora at Behring’s Straits in 1878-79 
is shown in the accompanying woodcuts. We never saw here 
the magnificent bands or draperies of rays which we are so 
accustomed to in Scandinavia, but only halo-like luminous arcs, 
which hour after hour, day after day, were unaltered in position. 
When the sky was not clouded over and the faint light of the 
aurora was not dimmed by the rays of the sun or the full moon, 
these arcs commonly began to show themselves between eight 
and nine o’clock P.M., and were then seen without interruption 
during midwinter till six, and farther on in the year to three 
o’clock in the morning. It follows from this that the aurora 
even during a minimum year is a permanent natural 
phenomenon. The nearly unalterable position of the arcs has 
further rendered possible a number of measurements of its 
