THE HEART OF THE ANTARCTIC 



readily change into other types. Curtains lose their form 

 and become nebulous; the hazy border of a cloud gives out 

 beams like an arch or searchlights; any type will suddenly 

 concentrate into a single beam or into a shapeless patch. 

 Some auror^e occurred which could not be classed with any 

 of the types recognised, but they were not common enough 

 to get special names. Two of the most striking aurora 

 are figured. 



Great Beam of Light, May 23, 1908 



On May 23 at 11 a.m. a great broad beam of light 

 appeared from behind a stratus cloud in the west from 

 Cape Royds, and grew upwards till it reached the zenith. 

 It was at first accompanied by some searchlight beams 

 (shown inclined to the right) which soon disappeared. 

 The broad beam illuminated some strips of cirrus in its 

 path, which were scarcely visible to right and left of it. 



It swung slowly down to the left, the lower end keep- 

 ing in the same apparent position, till it made an angle of 



390 



