MAGNETISM 



brilliant display was to be expected and this continued 

 with little reduction in intensity throughout the evening 

 hours. The eifect increased in brilhancy at about four 

 o'clock in the morning, and died away towards 7 a.m. 

 At one period of the year we experienced bright aurorge 

 frequently about three o'clock in the afternoon. Very 

 little colour was observed in connection with these aurorse 

 other than the usual yellowish-green tints, but at some 

 times the luminosity showed yellower than at others. In 

 some of the most brilHant displays the curtains were 

 bordered below by a narrow zone of deep crimson colour. 

 The displays were usually in the form of arches, which 

 showed minor convolutions and appeared as beautifully 

 draped curtains. These were sharply defined below but 

 merged insensibly into the heavens above; their depth 

 appears to have been many thousands of feet. Besides 

 the curtain aurorge, diffused nebulous lights were fre- 

 quently observed, often in connection with clouds. On 

 still cold evenings a faintly luminous mist enveloped Ross 

 Island, and this seemed to have some connection with the 

 nebulous aurorse. In fact, very early in the winter a 

 nebulous type of aurora was seen on one occasion to 

 descend between us and the slopes of Erebus, apparently 

 only about five or six thousand feet in height above us. 



When at their greatest brilliancy the displays were 

 powerful enough to throw shadows but were yet insuffi- 

 ciently strong to allow of their being photographed. We 

 obtained impressions on photographic plates after about 

 ten minutes' exposure, but as the curtains had altered their 

 shape during the interval, the result was of little value. 

 With regard to the curtain aurorge, when once outlined 

 in the sky they experienced spasmodic kindling, the waves 

 of light travelling usually in one definite direction. This 

 has the effect of producing to the eye the appearance of 



voi.n.-25 385 



