The Scientific Advantages of an Antarctic Expedition. 441 



South Georgia during the period of International Observations in 

 1882-83. Of course, the magnetic South Pole and the situation of 

 the foci above mentioned are in close connection with these facts, 

 but the reason for this distribution remains unexplained. In 

 agreement with this is the relative frequency of the South Polar 

 lights within one and the same epoch. The map here shows the 

 results of a discussion of all observations on southern lights, and, 

 as may be perceived at a glance, the conformity with the fact just 

 mentioned with regard to the region of maximum disturbance is 

 striking. It may be mentioned, also, that a discussion of the mag- 

 netic state of our earth for the epoch 1885 has yielded a curious 

 fact (perhaps merely a coincidence), namely, that Dr. Schmidt, of 

 Grotha, has calculated that part of the magnetic action of our earth 

 which lies outside it, above the earth's atmosphere probably, and has 

 arrived at the conclusion that this part amounts to about l/50th 

 part of the entire potential. The curves which he constructed, 

 based on this calculation, show likewise a close coincidence with 

 the frequency of the southern lights. This requires to be further 

 investigated, for it is perhaps a mere coincidence. The question 

 of atmospheric electricity, yet under the shadow of a hypothesis of 

 more or less probability, may yield, in connection with the matters 

 touched upon, some results more definite than science has hitherto 

 been able to divine. Under all these circumstances we perceive that 

 there are a number of problems yet to be solved, which must stimu- 

 late the scientific world to enter upon a close and conscientious 

 examination of a region still enveloped in total darkness. 



The necessity of climatological researches within the Antarctic 

 region has already been so much urged that it does not appear 

 necessary for me to enter upon the matter. That it must remain 

 impossible to arrive at exact climatological constants, so long as we 

 do not know the winter temperature in that large area round the 

 South Pole and bounded by the South Polar circle, is evident to 

 every one conversant with the subject and does not require any 

 further illustration. 



With regard to atmospheric pressure there is another curious 

 fact which requires investigation, only to be carried on by observa- 

 tions within the Antarctic. The excess of barometric pressure in 35° 

 latitude over that in 60° latitude amounts in the northern hemi- 

 sphere to 19*0 mm. and in the southern hemisphere to only 3' 7 mm. 

 Here is another problem worthy of examination. 



With the recital of these few facts, which suffice to prompt us to 

 institute a vigorous examination of the South Polar regions the 

 series is far from being exhausted. There is the question of the 

 geoid-deformation, the phenomena of the tides, the structure of the 

 ice and its drifting, especially the interesting fact of the appearance 



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