32 



Before leaving the subject of magnetism, I would mention another 

 result lately obtained in that department of science, which we owe 

 to one of those voyages to the Arctic Seas, which some are wont to 

 describe as useless to mankind, and a foolish exposure of human life. 

 Capt. Maguire commanded the Plover, one of the ships employed 

 in the Franklin search in the years 1852-3-4, and he was stationed 

 from the summer of 1852 to that of 1854 at Point Barrow, the most 

 northern cape of the American Continent, between Behring's Strait 

 and the Mackenzie River. During every hour of seventeen months 

 unremittingly did Capt. Maguire and his officers observe and record 

 the variations of the magnetic declination and the concomitant 

 auroral phenomena, in an observatory built of ice and lined with 

 seal-skins ; in a most dreary and unenviable locality indeed, but still 

 one of the most favourable for such investigations. The observa- 

 tions, as usual, were reduced under the direction of our Treasurer, 

 and they reveal this important fact : On comparing them with those 

 made at Toronto, it was found, that although the deflections of the 

 same name at the two stations did not correspond, there existed, on the 

 other hand, a very striking and remarkable correspondence between 

 the easterly disturbances at Point Barrow and the westerly at Toronto, 

 and vice versa. In the case of the regular solar-diurnal variation, 

 the easterly and westerly extremes are reached at both stations at 

 nearly the same hpurs ; but in the case of the abnormal diurnal 

 variation, the progression is reversed, the easterly extreme at the one 

 coinciding very nearly with the westerly at the other. The absolute 

 disturbing force appears to be much greater at Point Barrow than at 

 Toronto, and in correspondence therewith is the frequency of the 

 auroral manifestations. During the six months of darkness in the 

 two successive winters, out of 3625 hourly observations, there were 

 1077, or 30 per cent., at which the aurora was visible. It appeared, 

 also, that 1 A.M. was the hour at which aurora most frequently ap- 

 peared, and that between 11 A.M. and 3 P.M. is the period of mini- 

 mum frequency. 



The above interesting results have suggested to the British Asso- 

 ciation the importance of instituting magnetic observations for an- 

 other winter or two at some point, so situated between the above- 

 mentioned two stations, as to render it a proper locality for ascer- 

 taining the laws on which the remarkable and characteristic analogies 



