ON THE AURORA BOREALIS, 



CUMBERLAND-HO USE. 



EXTRACTED FROM THE JOURNAL OF LIEUT. ROBERT HOOD, R.N. 



The most material information we had obtained at this period regarded 



the height of the Aurora from the earth. 



The following is the result of the observations that were made at the Bas- 

 quiau Hill, and at the same time by Dr. Richardson at Cumberland-House. 

 The instruments used for the purpose were two small wooden quadrants, re- 

 volving on pivots, and furnished with plummets. Our chronometers were 

 previously regulated ; though great accuracy was not necessary in this parti- 

 cular, as the arches of the Aurora are sometimes stationary for many minutes. 

 On the 2nd of April, the altitude of a brilliant beam was 10° 0' 0", at 

 lOhs. lm. 0s. p. m., at Cumberland-House. Fifty-five miles S. S.W., it was 

 not visible. As the trees at the latter station rose about 5° above the horizon, it 

 may be estimated, that the beam was not more than seven miles from the earth, 

 and twenty-seven from Cumberland-House. On the 6th of April, the Aurora was, 

 for some hours, in the zenith at that place, forming a confused mass of flashes and 

 beams; and in lat. 53° 22' 48" N., long. 103° 7 17" W., it appeared in the 

 form of an arch, stationary about 9° high, and bearing N. b. E. It was there- 

 fore seven miles from the earth. On the 7th of April, the Aurora was again 

 in the zenith before 10° p. m., at Cumberland- House, and in lat. 53° 36' 40" N., 

 and long. 102° 31' 41" ; the altitude of the highest of two concentric arches at 

 9hs. p. m., was 9°; at 9hs. 30m., it was 11° 30'; and at lOhs. 0m. 0s. p.m., 

 15° 0' 0", its centre always bearing N. b. E. During this time, it was be- 

 tween six and seven miles from the earth. After lOhs. p. m., it covered the 

 sky at Cumberland- House, and passed the zenith at the other place. 



These observations are opposed to the general opinion of meteorologists ; 

 they are nevertheless facts. We have sometimes seen an attenuated Aurora 



flashing across 100° of the sky in a single second; a quickness of motion 



