RECORD OF AURORAL PHENOMENA. 57/ 



The latter phenomenon made some of its grandest displays on the 26th of October, the 2d of 



November, and the 7th of December. 

 On all these occasions, the disturbed motions of the magnetic needle were very remarkable, and a 



most careful series of observations convinced the party that they had a close connection with 



the direction of the beams of light of which the Aurora was composed. 

 My observations also led me to conclude that the deviations of the needle were, in a certain degree, 



connected with changes in the weather; for, previous to a gale or a snow storm, the deviations 



were always considerable, but, during the continuance of the gale, the needle almost invariably 



remained stationary." — 2 Franklin, C6. 



N. B. — 1. Grandest displays of Aurora. 



2. Disturbed motions of the needle on these occasions very remarkable. 

 3 Deviations of the needle connected with changes in the weather. 



Fort Franklin.— Lat. 65° 11' 5G" N. Long. 123° 12' 44" W. February 14, 1826. Franklin. 



"On the 14th, at 45m. after nine a. m., the arched form of the clouds, and the appearance of a 

 collection of rays projected from the sun's disk in the shape of a fan, strongly resembled the 

 coruscations of the Aurora. The atmosphere was misty; temperature in the shade +8° 5', 

 and when the thermometer with a blackened bulb was exposed to the sun's rays, it rose to +43°. 

 The magnetic needle, at nine a. m., was perceived to have made a greater deviation to the westward 

 than usual at that hour, and I imagine that the cause of this increase probably arose from the 

 atmosphere being then in a state of electricity, similar to that in which it is when the Aurora 

 appears in hazy weather; on which occasions we have observed that its coruscations have the 

 strongest effect in causing aberrations of the needle." — 2 Franklin, 12-3. 



N. B. — 1. Arched form of clouds noticed at 9h. 45m. a. m. 



2. At 9h. a. m., magnetic needle was perceived to have made a greater deviation than usual. 



Fort Franklin.— Lat. 65° 11' 56" N. Long. 123° 12' 44" W. 1825-26-27. Franklin. 



"The results of the observations on this phenomenon made during the present expedition coinciding 

 with the remarks on the same subject giveu at much length in the Appendix to my former Nar- 

 rative, I shall here confine myself to the mention of a few brief deductions from a careful exami- 

 nation of our registers at Bear Lake. 

 A careful review of the daily registers of the appearance of the Aurora, has led me to form the 

 following general conclusions : — 



1. That brilliant and active coruscations of the Aurora Borealis cause a deflection of the needle 

 almost invariably, if they appear through a hazy atmosphere, and if the prismatic colors are 

 exhibited in the beams or arches. When, on the contrary, the atmosphere is clear, and the 

 Aurora presents a steady dense light of a yellow color, and without motion, the needle is often 

 unaffected by its appearance. 



2. That the Aurora is generally most active when it seems to have emerged from a cloud near the 

 earth. 



3. When the Aurora is very active, a haziness is very generally perceptible about the coruscations, 

 though the other parts of the sky may be free from haze or cloud. 



4. That the nearest end of the needle is drawn towards the point from whence the motion of the 

 Aurora proceeds, and that its deflections are greatest when the motion is most rapid. The 

 effect being the same whether the motion flows along a low arch or one that crosses the zenith. 



5. That a low state of temperature seems favorable for the production of brilliant and active corus- 

 cations; it being seldom that we wituessed any that were much agitated, or that the prismatic 

 tints were very apparent, when the temperature was above zero. 



6. That the coruscations were less frequently visible between the first quarter and the full moon, 

 8 



