THE HEART OF THE ANTARCTIC 



northerly and westerly direction. This fact was further 

 ascertained by actually sledging inland from the Drygalski 

 ^Barrier, following as nearly as possible the magnetic 

 meridian, until the dip readings showed approximate 

 verticality. Here the flag was hoisted. The determination 

 of the exact centre of the magnetic polar area could not 

 be made on the spot, as it would involve a large number 

 of readings taken at positions surrounding the Pole. The 

 execution of such observations under conditions of such 

 low temperature and prevalent high winds is a matter of 

 very great difficulty, and when it is borne in mind that 

 many days would be necessary for the operations, the 

 impossibility of such a course for sledging-parties such as 

 ours is obvious. 



The Aurora Australis 



The aurora was first ob seized during the evening of 

 March 26, 1908. Earlier in the season the daylight over- 

 powered the light of the aurora, and therefore observa- 

 tions were not possible. After October 4, 1908, likewise, 

 observations were not possible on account of the continu- 

 ous dayhght. Nevertheless, the aurora was probably in 

 the heavens during the summer-time, as observations made 

 by the ship's party in lower latitudes showed. As the 

 Nimrod travelled north into regions where dark nights 

 prevailed, auroral displays were observed both in the latter 

 part of February 1908 and early in March 1909. Between 

 the dates of March 26 and October 4 scarcely twenty- 

 four hours passed without some display. At times the 

 auroral hghts were present in the heavens for many days 

 together, though of course at full moon the brilliancy of 

 the light obscured the more dehcate auroral effects. Cer- 

 tain hours of the day were attended by greater displays 

 than others. About half-past seven in the evening a 



384 



