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POPULAR SCIENCE MONTHLY. 



of the auroral light, it is not yet clearly known. There is also as 

 much dispute as to whether any sound accompanies the aurora. The 

 northern nations believe in the existence of this sound, like the rus- 



tling of silk or of straws, a " crackling " coinciding with the darting 

 of the rays. This also is not w^ell proved. In arctic regions it is 

 probably confounded with the incessant crackling of fields of snow 

 and the faint clicking of small needles of ice in the process of their 



