302 ANTARCTIC EXPLORATION. 



it most closely, and it has a zone of maximum intensity which is placed 

 obliquely between the parallels of 60° and 70° K The length of its 

 meridional excursion varies from year to year, decreasing and increasing 

 through tolerably regular periods, and reaching a maximum about every 

 11 years, when, also, its appearance simultaneously attains to its great- 

 est brilliancy. Again, it has its regular yearly and daily movements or 

 periods. At the winter solstice it reaches its maximum annual intensity, 

 and it has its daily maximum at from 8 p. m. and 2 A. M., according to the 

 latitude. Thus at Prague, in latitude 50° jST., the lights appear at about 

 8.45 P.M.; at Upsala, latitude 60° K, at 9.30 P. m.; atBossekop, 70° N., 

 at 1.30 A. M. Now, while these data may be true for the northern 

 hemisphere, it remains to be proved how far they apply to the southern. 

 Indeed, seeing tha* the atmosphere of the latter region is moister and 

 shallower than tliat of the former, it is probable that the phenomena 

 would be modified. A systematic observation of the Aurora Australis 

 at a number of stations in high latitudes is therefore desirable. 



Whether or not there is any connection between auroral exhibitions 

 and the weather is a disputed point. Tromholt believes that such a re- 

 lationship is probable {Under the Hays, 1283). He says that, "how- 

 ever clear the sky, it always became overcast immediately after a vivid 

 exhibition, and it generally cleared again as quieklj^^ {Under the Rays, 

 1235). Payer declares that brilliant auroras were generally succeeded by 

 bad weather {Voyacje of Tegethoff, 1324), but that those which had a 

 low altitude and little mobility appeared to precede calms. Eoss re- 

 marks of a particular display " that it was followed by a fall of snow, 

 as usual" {Rosses Voyage, 1312). Scoresby appears to have formed 

 the opiuion that there is a relationship indicated by his experience. It 

 is, therefore, allowable to regard the ultimate establishment of some con- 

 nection between these two phenomena as a possible contingency. If, 

 then, we look at the eleven-year cycle of auroral intensity from the 

 meteorological point of view, it assumes a new interest, for these periods 

 may coincide with the cycles of wet and dry seasons which some 

 meteorologists have deduced from the records of our Australian climate, 

 and the culmination of the one might be related to some equivalent 

 change in the other. For if a solitary auroral display be followed by a 

 lowered sky, surely a period of continuous auroras might give rise to a 

 period of continuous cloudy weather, with rain and snow. Fritz -con- 

 siders that he has established this eleven-year cycle upon the strength 

 of auroral records extending from 1583 to 1874, and his deductions have 

 been verified by others. 



In January, 1886, we had a wide-spread and heavy rainfall, and also 

 an auroral display seen only at Hobart, but which was sufficiently pow- 

 erful to totally suspend communication over all the telegraph lines situ- 

 ated between Tasmania and the China coast. This sensitiveness upon 

 the part of the electric currents to auroral excitation is not novel, for 

 long experience ou the telegraph wires of Scandinavia has shown that 



