ANTARCTIC EXPLORATION AND RESEARCH 265 



Likewise in the elucidation of the problem of terrestrial magnetism, 

 the determination of the magnetic elements is required at chains of 

 stations around and across the Antarctic regions. Also, the reoc- 

 cupation of former stations is particularly desirable. 



In the matter of the aurora australis careful and detailed obser- 

 vation of the manifestations is anxiously awaited. This is the more 

 desirable, for in the Antarctic regions the displays appear to exhibit 

 more clearly than in the Arctic certain fundamental features which 

 may assist in arriving at a satisfactory explanation of that remarkable 

 phenomenon. In this regard, however, merely picturesque descrip- 

 tions should be avoided and the observer should concentrate on ob- 

 servations as to the trend of auroral curtains, the direction of motion 

 of the luminous impulses, etc. As an example for those unacquainted 

 with this branch of observation some of the features that might prof- 

 itably be observed are to be found in a recently published report of 

 the manifestations seen in Adelie Land.^^ 



VOLCANISM 



The Antarctic is not without its share of volcanoes. Though much 

 has been gleaned concerning the active cone of Mt. Erebus, of several 

 less important extinct volcanic centers in the Ross Sea region, of 

 Gaussberg in Kaiser Wilhelm II Land, and of certain not long extinct 

 centers in West Antarctica, there still remains much to be studied. 

 The Balleny Islands are an active volcanic group, as yet unexplored. 

 Other submarine and subaerial volcanoes extinct or dormant may 

 yet be found along the trend lines of crustal weakness already known. 



Condition of the Air 



The Antarctic Continent is so isolated from other lands and so 

 universally covered by ice that dust particles in the atmosphere 

 are reduced to a minimum. The remarkable purity of the air in this 

 regard is quite striking. Observations as to the quantity of dust 

 motes and bacteria in the air are, therefore, of special interest. Fur- 

 ther, the attrition of the snow particles flying at high velocities in the 

 blizzard winds at very low temperatures causes unusual electrifica- 

 tion of the atmosphere. As a result there is much silent electrical 

 discharge — St. Elmo's fire — in areas of prevailing strong winds. 

 This state of affairs is conducive to the production of a high ozone 

 content in the atmosphere. Consequently estimations of the ozone 

 content are likely to prove interesting. 



On account of the existence of a continent around the south pole 

 and the consequent intense cold that prevails throughout — far lower 



" Douglas Mawson: Records of the Aurora Polaris (Australasian Antarctic Expedition, Scientific 

 Reports, Ser. B, Vol. 2: Terrestr. Magnetism and Related Observations, Part I), Sydney, 1925. 



