New national era. [volume] (Washington, D.C.) 1870-1874, 1872-10-31
EH' Aurora ROreaIis.

l nf1u
| than the Aurora Borealis. To tell vbotL Us,
been conjectured about il would fill a hoaI''
to tell what we know I" for sure. ~ rs cb;Id,n'
say, will not require much time or spacn ~
the first place, then, the Aurora is in or IN III
our atmosphere it is a terrestrial. NOT o.,
astronomical, phenomenon. This is eyidon4
| from many considerations which need not Lo
| dwelt upon here. 1t is enough to say that
in many cases, the position of an auroroi
streamer can be pretty accurately dcterm;nooa,
! by observations from two or three station
on the earth, some fifty miles or more anar,
and we usually find the base of the streamer
to be at an elevation ranging from thirty n
| nifty miles, while its summit attains a heobt
| OF from 100 to even COO miles 1t has been
claimed by some that they have seen auroraI
| streamers descend between them and a build.
ing or hill. This, however, is so improba.
| bic, IN view OF many other circumstances
that it seems more likely the observers wcrs
victims OF some illusion. At any rate wa
wait for further evidence before acceptinG tho
fact. Sometimes the aurOral matter drifts
| through the sky in bands and arches Of Eobt
! More commonly, when there is any great oc.
| tlylty, it collects itself into streamers "a
they are called, columns Of light, which stand
parallel to each other, like so many forest
trees. But they do not stand vertically.
each places itself as if it were an enormous
compass-needle floating free in air. Hence
when the display is perfect, and the observer
stands directly underneath, these pillars Of
fire converge by perspective to one point in
the sky, and there form the eye or crown of
the aurora. This is situated at that point in
the sky to which the dipping-needle is d.
| rected-a point about fifteen degrees south of
the zenith, in our attitudes. This fact of
itself proves connection between the aurora
and the earth's magnetism Moreover, every
important auroral display is felt at all the
| magnetic observatOries as "maonetic
Storm" which puts all the needles of the
| different instruments into state of tremor
and excitement.
An aurora in New York disturbs the in
struments at Rome, and does 1t instantly.
| The English ObservatOries feel the effects of
| Australian auroras, at the very hour and
minute OF their occurrence. Generally the
magnetic disturbances are too small to be no.
ticed with an ordinary compass (; but some
! times the deviatiOns amount to several de-
grees, vastly to the dsconcertment of any
unlucky surveyor who may happen to be run
ming iarm-line at the time-for aurOras &C.
cur by day as often as by night.
When we inquire into the cause and nature
of the connection between magnetic storms
and auroras, we get no certain answer vet:
nor is it even settled which is cause and which
effect. or whether both series Of phenomena,
the magnetic and the luminous NAV not be
the Simultaneous effect of some far-off action.
Here are questions squarely proposed by
science, and the probability is that before the
century is finished, she will have tortured ma
ture into some reply.
| As to the cause of the light the mO,r prpl,-
able view, and the one almost universally
adopted, is that it is produced by some form of
| electric discharge through tho rareiied gases
which form the streamerS. This supposition
agrees well with the facts observed, such as
the flashing and dancing of the light, the
magnetic direction of the streamers, and es-
pecially the effects upon the telegraph lines
through which, during an aurora, powerful
currents pass and repass in the most capri-
cious manner. But the supposition is not
without its difficulties; an electric discharge
implies two charged bodies, with q medium
between them. The earth is one of the
bodies the streamers form the medium OF
communicatiOn-but with what? The ques-
ton is by no means unanswerable but of
the many answers yet proposed, no one is
wholly satisfactory. 1t may be noted in this
connection, that if we regard the aurora
streamers merely rs huge magnets drifting
over the country, all the telegraphic effects
would be accounted for.
As to the nature of the luminous matter
we are, as yet, ignorant, but not hOpelessly
, so. The spectroscepe has done it's best; it
informs us that the matter is gaseous and
gives us, so to speak, its signature, but as
yet chemists cannot decphcr and read it.
Its spectrum is characterized by bright line
! in the greenish yellow, which can be seen
under all circumstances when the least
aurOral light of any kind is visible. This
line is not, as has been often stated Of late,
the same with the bright line which characters
ICES the spectrum Of the suns corona. When
, the aurora is very bright and strongly col
) ored, then several other lines and bands,
! mostly very faint, appear in its spectrum.
! 1t is one of the faintest of these faint lines,
, which seems to coincide with the corona line,
! and the observations of this aurora line have
\ been so few and so difficult that no great
! confidence is to be placed in the result As
regards the matter of which the streamera
are composed, We must, then, for the present,
limit ourselves to asserting that it is gaseous,
:, and is not, probably, the samo as ordinary
air. Probably, before many years elapse,
/, we shall know more about it.
One remarkable and suggestive fact re-
mains for notice. Remote as is the sun, it is
: certain that aurOral manifestations are, to a
certain extent, connected with disturbances
of the solar surface. \ numerous array of
r facts points to most curious, direct, inti-
mate, and as yet, ineXplicable relation be-
tween the state of affairs at the sun and the
= magnetic condition of the earth. Professor
: LOOMS and others have shown that just
f when the solar surface has been most broken
c up by spots, then, precisely, aurOras have
/, been most numerous and brilliant, and rice
2 rersa. There is a regular period in the fire.
: quency and number of the spots, and this
t same period is observed by the aurora also.
f Then, of late. many cases have been re-
a corded in which remarkable outbreaks on the
b sun have been Immediately followed by bright
: auroras on the earth, and the instances have
: become SO numerous and of such Il character
: as quite to preclude the idea of accidental
: coincidence. To ascertain the cause and
= nature of this connection is one of the most
= interesting problems now proposed to sci
| ence.-N. I. Times.
The End OF Brunswick.