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VII r.
A U R O R A B O R E A L I S .
I S e e T j n n t r p ‘ “ '’•’“/ ‘“ “ ‘f A “™ - Borealis in th e a a taarn s of
1826 an d of 1827^ From th e 2 5 th o f A n g u s t un til the 9 th October, about tho time o f the
dep a rtu re o f th e Blossom from th e n o rth e rn regions in both years, this beautiful meteor was
vmible on ev e ry m g h t th a t was clear, or when the clouds were thin and e le v ated * . I t is
remarkable th ak in both yea rs, its first appe,arance was on tlie 2 5 th Au g u st. T h e season
of 1826 was distinguished b y an almost un in terru p te d succession of fine w e ather and easterly
wmds, and that of the following y ea r by continued boisterous weather and winds from the
westward. I n th e former year, the weather bein g fine, tl.e Au ro ra was more frequently
seen han m th e la tte r; b u t in 1827 th e displays were brighter, and th e lig h t more freq
u en tly passed to th e southward o f the venitli. I t never appeared in w e t weather
In 1826, when as before mentioned, th e weather was settled, th e Aurora g en e rally
began in th e W .N .W . an d passed over to th e N .E ., u n til a certain period, aftre which
It as re g u la rly commenced in th e N .E . and passed to th e N .W . ; whilst in 1827 th e ap
pearance o f th e meteor was as unce rtain as th e season was boisterous and changeable T h e
period when this change in th e course o f th e lig h t took place coincided v e ry n e a rly with
th a t o f th e e q u in o x ; and as th e An ro ra Borealis has been supposed to be aifeoted by that
o ccurrenre, we imagined th a t th e change m ig h t be in some way owing there to, b u t the
irre g u la rity of th e meteor in this re sp ect in 1327 gave a contradiction to this hypothesis.
I t was however, uniform in m aking its appearance always in th e n o rth ern hemisphere, and
gen e ra lly m th e form o f elliptical arches from 3» to 7“ o f alü tu d e , n e a rly parallel with the
magnetic equator. Those arches were formed by short perpendicular rays passing from one
q u a rtm to the other with a lateral motion, or by th e ir b ein g met by similar rays from the
opposite dirre tion. T h e arches, when formed, in gene ral remained n ea rly stationary, and gave
out coruscations, which streamed toward th e zenith. W h e n a t re s t the lig h t was colourless,
b u t when an y movement took place it exliibited prismatic colours, which increased in strength
as th e motion became rapid. T h e coruscations seldom reached our zenith, and more ra rely
passed to th e southward o f it, b u t wheu th a t occurred tho display was always b rillia n t: on
one occasion only th e y extended to th e southern horizon.
W e remarked, th a t when an y material change was about to occur one extremity of tl.e
arch became illuminated, and th a t this lig h t passed along the belt witl. a tremulous hesita
tin g movement toward th e opposite end, exhibiting th e colours of th e rainbow. An idea
may be formed o f this appearance from th e examination o f th e rays o f some moluscous
animals m motion, such as th e nereis, b u t more particula rly th e heroes. Captain P a rry has
• In 1826 it was visible on twenty-one nights, in 182? only eleven.
compared its motion to the waving of a ribbon. S ee Second Voyage, p. 144. As the lig h t proceeded
along the arch, coruscations emanated from i t ; and as the motion became violent the
curve was often deflected and sometimes broken into segments, which we re brightest a t their
extremities, and in gene ral highly coloured. W h e n one ra y o fth e Aurora crossed another,
the point of intersection was sometimes marked by a prismatic spot, very similar to th at
which occurs in the intersections of coron?e ab o u t th e moon, b u t far more b rillia n t; and when
th e segments, wliich g en e rally crooked toward the zenith, were much curved, colours were
perceptible in the bend. Genera lly speaking, afte r an y brilliant display, th e sky became
overcast with a dense haze, or with lig h t fleecy clouds.
T h e Aurora has been frequently observed to re s t upon a dark nebulous substance, which
some persons have supposed to b e merely an optical deception, occasioned by th e lustre of
the a r c h ; but this appearance neve r occurs above the arch, which would be the case, I think,
if these surmises were well founded. W e sometimes saw this cloud before an y lig h t was
visible, and observed it afterwards become illuminated a t its upper surface, and exhibit all the
appearances above mentioned. I t was the gene ral opinion th a t th e lustre of all the stars was
diminished by the Aurora, b u t particularly by this p a rt of it. Captain P a rry , however, observes
in his Journa l, p. 142, th a t tlie stars in this dark cloud were unobscured, except by
tb e lig h t of the Aurora. H e , however, agrees with us in the lower p a rt of th e arch being
always well defined, and in the u p p e r bein g softened off, and gradually mingled w ith tbe azure of
th e sky. I t is worthy o f notice, th at we never observed any rays shoot downwards from this
arch, and I believe the rema rk will apply equally to the observations o f Captains P a rry and
Franklin. W e frequently observed the Aurora attended by a th in fleecy-cloud like substance,
which, if not p a rt o f the meteor, furnishes a proof of tlie displays having taken place within
the region of our atmosphere, as the lig h t was decidedly seen betwe en it and th e earth.
Th is was particulai-ly noticed on the 28th of September, 1827. T h e Aurora on th at
n ig h t began by forming two arches from W . by N. nortliward to E . by N., and about eleven
o’clock threw out brilliant coruscations. Shortly after the zenith was obscured by a lucid
haze, which soon condensed into a canopy of light clouds. W e could dete ct th e Aurora
above this canopy by several b right arches being refracted, and by brilliant colours being
appa rent in the interstices. S hortly afterwards the meteor descended, and exhibited a
splendid appearance, without an y interru p tio n from clouds, and th en retired, leaving the
fleecy stratum only visible as a t first. T h is occurred several times, and left no doubt in my
own mind of the Aurora b ein g a t one time above and at another below th e canopy formed about
our zenith. 1 must n o t omit to observe here, that on several occasions, when the lig h t thus
intervened between the earth and the cloud, brilliant meteors were p recipitated obliquely
toward the south and south-west horizons.
T h is supposition of the lig h t being a t no g re a t elevation is stren g th en ed by the different
appearances exhibited by the Anrora a t th e same times to observers n o t more than from ten
to th irty miles apart, and also by its being visible to persons on board the ship a t Chamisso
Island, afte r it had vanished in Escholtz Bay, only ten miles distant, as well as by the Aurora
being seen by tbe barge detached from the Blossom several days before it was visible to persons
on board the ship, about two hundred miles to th e soutliward of her. Captain F ran k lin has
mentioned a similar circumstance in his notices on th e Aurora Borealis in his first expedition,
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