THE HEART OF THE ANTARCTIC 



sun was nearly in the zenith, and more than an eigth part 

 of the circle was visible. The lateral ones were quite 

 short, and like the ordinary sun-dogs, but the centres of 

 the circles away from the sun. This display is here 

 figured. 



The iridescent colours of these sun-dogs were not 

 disposed in broad bands as in the rainbow, but in a 

 succession of minute coloured streaks, each repeating all 

 the colours, and concentric with the whole ring. 



Rainbow 



On December 22 the only rainbow was seen, that is 

 to say there was a bow in the sky opposite to the sun, and 

 rather less than a semicircle. It was visible from 10.30 

 P.M. to near mid-night, and was therefore approximately 

 in the north. It was like a moon rainbow in the faintness 

 of the colours. It looked simply like a lighter streak amid 

 the slight haze which prevailed. Some of those who saw it 

 could distinguish a faint red band on the outer side of the 

 bow, others could only distinguish a pale yellow and a 

 paler green towards the outside. There was a deep band 

 on the inside, of pale bluish or purple. It appeared quite 

 near, coming down in front of hills which were less than 

 a quarter of a mile away. The essential difference be- 

 tween such a bow as this, and the prismatic arch seen at 

 sunrise and sunset, is that it is a band of narrow limits, 

 while the spectrum of the other extends from the top of 

 the arch down to the horizon. 



Iridescent Clouds 



The sketch is intended to show the bands of colour 

 (vivid purple, orange, green, &c.) on the margins of the 

 cloud, and the central patch. Each cloud has a broad 



376 



