*
[footnote] *Farquharson in the 'Edinburgh Philos. Journal', vol. xvi., p.
304; 'Philos. Transact.' for 1829, p. 113.
[The height of the bow of light of the Aurora seen at the Cambridge
Observatory, March 19, 1847, was determined by Professors Challis, of
Cambridge, and Chevallier, of Durham, to be 177 miles above the surface of
the Earth. See the notice of this meteor in 'An Account of the Aurora
Borealis of Oct. 24, 1847', by John H. Morgan, Esq., 1848.] -- Tr.]
The most recent observers are disposed to place the phenomenon in the region
of clouds, and not on the confines of the atmosphere; and they even believe
that the rays of the Aurora may be affected by winds and currents of air, if
the phenomenon of light, by which alone the existence of an electro-magnetic
current is appreciable, be actually connected with matrial groups of
vesicles of vapor in motion, or, more correctly speaking, if light penetrate
them, passing from one vesicle to another. Franklin saw near Great Bear
Lake a beaming northern light, the lower side of which he thought
illuminated a stratum of clouds, while, at a distance of only eighteen
geographical miles, Kendal, who was on watch throughout the whole night, and
never lost sight of the sky, perceived no phenomenon of light.
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