RECORD OF AURORAL PHENOMENA. 35 



I did not observe any Aurora after this day, but Mr. Hood saw it on the Gth, 10th, 11th, 12th, 

 and 13th, after which date there was constant daylight, which prevented us from seeing it." — 

 1 Franklin, 554-569. 



Fort Enterprise.— Lat. 64° 28' 24" N. Long. 113° 6' W. January— May, 1822. Franklin. 



"The appearance of the Aurora, and the disturbance it occasioned on the motion of the needle at 

 Fort Enterprise, was so frequent, that the mean monthly variation must have been deduced from 

 but few observations if they had been rejected. 



The circumstance of the mean variation being least at midnight there, and at Moose-Deer Island, 

 was evidently caused by the frequent disturbance in the motion of the needle ickich the Aurora 

 occasioned; for on those days when it was not visible, the mean diurnal variation followed the 

 course Mr. Hood had observed it to do at Cumberland House, being most easterly at the time 

 of the first observation in the morning, and least between three and four in the afternoon. 



The change in the diurnal variation in these parts of North America seems to be governed by the 

 same law as that in England, as the decrease in easterly variation between the morning and 

 afternoon is in fact a motion of the needle to the westward." — 1 Franklin, 629. 



N. B. — 1. Motion of the needle frequently disturbed by the appearance of the Aurora. 



2. Mean variation being least at midnight, evidently caused by the frequent disturbance in 

 the motion of the needle which the Aurora occasioned. 



Fort Enterprise.— Lat. 64° 28' 24" N. Long. 113° 6' W. Winter 1820-21. Hood. 



"Appearances of the Aurora at Fort Enterprise. Extracted from the Journal of Lieutenant Hood, 

 R. N.— January 10, 1821. At 8h. p. m., an arched Aurora N. N. W. to N. N. E. At lib. 

 p. in., a double arch, much broken but not bright, from N. W. to S. E. 



11th. At midnight, faint Aurora from west to east. 



14th. At midnight, five arches of Aurora from N. W. to S. E. A large Corona Borealis." — 1 

 Franklin (Hood), 588. 



Fort Enterprise.— Lat. 64° 28' 24" N. Long. 113° 6' W. 1820-21. Hood. 



" On the Aurora Borealis at Fort Enterprise. Extracted from the Journal of Lieutenant Robert 

 Hood, R. N. — During the summer of 1820, the Aurora was only once visible before the mouth 

 of August, when the nightly temperature of the air was generally below 50°. The late con- 

 tinuance of daylight, and the few opportunities which we had of making observations at the 

 most favorable hours, render it possible that the Aurora may have sometimes appeared in this 

 long interval without our knowledge. But those opportunities were sufficiently numerous to 

 convince me that it is actually very seldom present in these regions during the summer. 



The number of Aurora; visible in August, 1820, was ten; in September, six; in October, seven; 

 in November, eight; in December, twenty; in January, 1821, seventeen; in February, twenty- 

 two; in March, twenty-five; in April, eighteen; and in May the brightness of twilight pre- 

 vented us from seeing more than nine. 



The whole amount is more than double the number of our observations at Cumberland House. 



It is worthy of remark, that the number of Aurora; in each month of both the winters, bears some 

 proportion to the thermometrical range." — 1 Franklin (Hood), 5S0. 



N. B. — 1. Number of appearances of Aurora at Fort Enterprise. 



2. More than double the number of observations at Cumberland nouse. 



"The shapes of the Aurora at its entry into the horizon and progress through the sky, maybe 

 reduced under two general descriptions. 



