INTRODUCTION. 



THE report which follows is based on data and sketches brought back on the 

 termination of the Expedition, which remained in my charge, and were not dealt with 

 until the conclusion of the war. 



In the normal course of events, they would have been sent to Dr. G. C. Simpson, 

 F.R.S., for analysis, since the auroral observations were made under his direction. 

 Only at the conclusion of the war were the data rediscovered, and they were then 

 analysed by myself, owing to pressure on Dr. Simpson of work in connection with 

 the meteorological report. 



Though all members of the Expedition took their turn on the auroral watch, 

 the credit for the observations lies chiefly with Dr. Simpson and with Major R. E. 

 Priestley, who organised and directed the scientific work of the Northern party. The 

 labours of the latter small party must indeed have been greatly increased by the 

 burden of auroral observations taken every two hours during the winter, and very 

 great credit is due to Priestley and to other members of this party for their zeal 

 and energy. 



One point which has not received attention in the report, but which cannot be 

 allowed to escape notice, is that on our Expedition, as on others, reports were made 

 that aurora had been seen at low altitudes and that a crackling noise accompanied 

 the display. 



The first instance was the report that aurora was visible between winter quarters 

 at Cape Evans and Mt. Erebus. The whole scientific staff at once left the hut to 

 investigate, but no such phenomenon was visible by that time. Major Priestley, 

 however, informs me that a similar phenomenon was reported from Cape Royds 

 during the Shackleton Expedition in 1908, this time by one of the scientific 

 staff.* 



A better authenticated case is reported by the Cape Adare observers, where on 

 one occasion the aurora was reported below the stratus clouds (on April 30th, 

 1911). 



On another occasion, it was reported by one of the seamen at Cape Adare that 

 a rustling sound accompanied the auroral display (June 13th, 1911). This report was 

 received with great scepticism, but Major Priestley informs me that, later, he himself 

 heard the noise which he firmly believes was associated with the aurora (on July 23rd, 

 1911). 



Though I have no personal knowledge of these two phenomena, it is clear that 



* Dr. Simpson (' Nature,' Sept. 12th, 1918) has discussed all the reported cases, and has come to 

 the conclusion, which is concurred in by the writer, that they were optical illusions. 



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