MAGNETISM 



a curtain. The folds and convolutions of these curtains 

 are sometimes very complicated, as shown in the figure. 



The picture shows part of a magnificent display of 

 curtain aurora, which was seen on April 28, 1908. The 

 whole sky was covered by a series of curtains, from horizon 

 to zenith, with very little blank space. The curtains were 

 much folded and convoluted. Similar displays occurred 

 on May 24, and on several other occasions. 



Part of Curtain Display, April 28 



Sometimes a single curtain formed a complete band, 

 more or less folded, which usually encircled the summit of 

 Mount Erebus at some distance. Such a band is shown in 

 the figure of the aurora of May 26. 



Similar complete rings occurred which did not go 

 behind the mountain. 



Curtains sometimes had the beams separated, or little 

 groups of beams separated from one another. These were 



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