OPTICAL EFFECTS 



blizzard after lunch. Mawson's right cheek was frost- 

 bitten, and also the tip of my nose. The wind was 

 blowing all the time at an angle of about 45° on the 

 port bow of our sledge. We just managed to do our 

 ten miles and were very thankful when the time came for 

 camping. 



The following day, January 9, a very cold plateau 

 wind was still blowing, the horizon being hazy with 

 low drift. We were now completely out of sight of 

 any mountain ranges, and were toiling up and down 

 amongst the huge billows of a snow sea. The silence 

 and solitude were most impressive. About 10.30 a.m. 

 a well-marked parphelion, or mock sun, due to floating 

 ice crystals in the air, made its appearance. It had 

 the form of a wide halo with two mock suns at either 

 extremity of the equator of the halo parallel to the horizon 

 and passing through the real sun. Mawson was able to 

 make his magnetic deviation observation with more com- 

 fort, as towards noon the wind slackened and the day 

 became gloriously bright and clear. In the afternoon it 

 fell calm. 



We were feeling the pinch of hunger somewhat, and 

 as usual our talk, under these circumstances, turned 

 chiefly on restaurants, and the wonderfully elaborate 

 dinners we would have when we returned to civilisation. 

 Again we accomplished our ten miles, and were now at 

 an altitude of over 7000 ft. 



January 10 was also a lovely day, warm and clear; 

 the snow surface was good and we travelled quickly. 

 There was a strong " Noah's Ark " structure in the 

 high-level cirrus clouds, there being a strong radiant 

 point respectively in the north-west and south-east, 

 and this made us somewhat apprehensive that we were 

 in for another bhzzard. These cirrus clouds were also 

 strongly curved with the concave side of the curve 



1Y5 



