PROCEEDINGS OF THE CANADIAN INSTITUTE. 137 



dark segments, flickering motions, etc. It lasted until nearly midnight." This is 

 the description which ofl'ers the closest analogy to Mr. Arctowski's aurora, except 

 that at Minneapolis no colouring is mentioned. But such resemblances are evidently 

 fortuitous. On September 9th the aurora seen on the Felgica was not reported 

 from Minneapolis, but of that aurora, the writer has analyzed eight American re- 

 ports. Their principal feature was the appearance and persistence of detached 

 masses of auroral radiance, while nothing of the kind is mentioned by Mr. Arc- 

 towski. These accounts, too, differ widely among themselves. It will be in order 

 then, to examine the hygrometric conditions of the atmosphere attendant on these 

 various kinds of display, for differences therein at various levels may cause the 

 variations in the auroral effects of the same magnetic influence— the height of the 

 streamers and their colouring. 



Arctowski writes as follows : — 



"Dans mes remarques, je n'ai insiste quelque pe.u que sur I'identite probable des 

 distributions geographiijues, par rapport au poles magnetiques, du phenomene auroral, 

 et j'ai pose un point d'interrogation au sujet de toutes les autres analogies qui sans 

 doute seront decouv^ertes dans la suite. Mais voila que M. Harvey vient de nous de- 

 montrer una remarquable concordance entre les aurores obaervees en 1898 au Canada 

 et dans le Nord des Etats Unis et celles que j'ai notees dans I'Antarctique." 



He further says : — 



" Mr. Arthur Harvey ayant sous la main des documents beaucoup plus iniportants 

 que ceux dont je dispose, je ne puis que I'inviter d'etudier, au point de vue auquel il est 

 place, les observations que la Commission de la Belgint publiera sous peu." 



He formulated several questions which we can now answer — 



Q. — Was the duration of the auroras of September 2nd and 9th, 1898, the 

 same in the Northern United States and Canada as at the station of the Belgica '^ 



Ans. — At tbe points where the aurorte were best noticeable, the duration was 

 about the same, but was not alike at all places. 



Q. — Were the fluctuations of intensity the same, north and south ? 



Ans. — They differed among themselves here, in this particular also. 



Q. — Do the maxima and minima correspond, to the moment? 



Ans: — No, these too differ here. 



Q. — Are the heights to which the auroral arch rises the same, at homologous 

 points, i.e., at points equi-distant from the magnetic pole and on the same magnetic 

 meridian ? 



Ans. — All we can say is that so far as our observations go, the higher the 

 latitude, the higher the arch aud its streamers rise. We cannot say which of the 

 places at which we have observers is to be considered most homologous to that of 

 the Belgica with respect to the magnetic pole. The positions are as follows : — 



N. magnetic pole lat., 70° 30' N. ; long., 97° W. 



S. magnetic pole lat., 73° 39' S. ; long., 146° 15' E. 



Toronto lat., 43° 39' N. ; long., 79° 24' W. 



Belgica lat. (September 2nd, 1898), 70° 00 S. ; long., 82° 45' W. 



Thus Toronto is 1,950 miles from the north magnetic pole, and the Belgica 

 nearly 2,300 miles from the south magnetic pole. Toronto is 600 miles east of the 

 agonic line, the Belgica 1,000 miles west of it. 



If, then, anything is to be gained by comparing aurora^ in homologous posi- 

 tions (which is very doubtful, as the condition of the air as to moisture, and elec- 

 trical conductivity at various heights is changeable and seems to govern the bril- 

 liancy and colouring aud even the character of the movements of auroral displays), 

 better points must be chosen than the Belgica's winter station and Toronto City. 



Beautiful auroral displays here are, however, tilings of the past, owing to the 

 electric lighting which now dims their brilliancy and dulls their colours. One must 

 get beyond the range of arc aud even incandescent lights to see the grandeur of 

 the mighty illuminations which formerly often seemed to rival, if not to transcend, 

 the glories of the dawn of day, whose name was for the time usurped. The 

 opaline clouds, delicately tinged with exquisite elusive tints of etherial amber, 

 verging on chrome yellow, Niagara green, rose pink or spring lilac — sometimes 



