THE HEART OF THE ANTARCTIC 



In summer-time on the plateau we observed the most 

 comphcated and gorgeous phenomena of this kind. 

 These were always best seen through coloured glasses. 



During the winter a fine example of a parselene 

 appeared between us and Mount Erebus. The image must 

 have been formed within a mile or two of us. 



In winter when the atmosphere was cold, clear and 

 still, similar rings could be artificially formed near the face 

 by breathing towards the moon. The moisture in the 

 breath freezes instantly on leaving the body, and the 

 optical effect is produced in the cloud of tiny floating 

 ice particles. 



Rings, coloured like the rainbow, closely investing the 

 moon, were of frequent occurrence during the winter 

 night. On one occasion a magnificent exhibition of this 

 kind appeared as a series of three coloured rings; that 

 nearest the moon showed the colours of the first order 

 in Newton's scale; the second and third rings showed 

 the second and third orders respectively. The effect was 

 similar to that seen when viewing a uniaxial crystal in 

 convergent polarised light along the principal axis. 



Other Colour Effects 



At certain periods of the year certain clouds are seen 

 very brightly coloured. This colouring is strong, and all 

 the colours of Newton's scale are seen as in the rainbow. 

 This succession of colours increases in a direction away 

 from the sun. The orders of colour increase successively 

 with a corresponding reduction in distinctiveness, until 

 too faint for observation. An isolated patch of cloud 

 illuminated in this way resembles a fragment of a mineral 

 Mke olivine viewed through an analyser under polarised 

 light. This phenomenon was strongly shown only for 



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