The Tipton advertiser. [volume] (Tipton, Cedar Co., Iowa) 1856-1962, 1869-05-27

southern horizon and bordertd b ths
auroral light.
Auroras are sometimes observed som.
ultaneously over large portioos Of the
globe. The aurora Of August q, 1859,
was seen throughout more than 40 4.
grees Of longitude from Eastern Europe
to Californis, and from 5amaica On the
south to an unknown distance n Bit.
ish America on the north. The surusA
Of September 2, 1859, was seen at thS
Sandwich Islands, 1t was seen through.
out the whole Of North AmeHiea ssA
Europe; and the disturb rb1rfcs IT tls mag
J netic needle indicated it prssencs
throughout all Northern Asix, althoss1ll
the sky was overcast, so that q A1aAr
places 1t could not be SEEN. An aurors
was seer at tho same time In SouslR
America and New Holland. The auro@
ras of September c5, ls4l, ind Nov. II,
ls4s, were almost equally extensive.
The height Of large number OF auroI
ras has been computed, aud the average
result for the upper limit Of the streuhfs.
ers Is $50 miles. From . multitude Of
observations IT r. concluded that the ~
rora seldom appears at an elevation l<ss
than about 45 miles ahove the esttA's
surface, and that II frequently extsndb
upward to an elevation OF 500 mI1se.-
! Auroral arches having well-denned
border are generally lees than 100 mlDes
in height. 4e'sf htaAs = A@ss
Auroras are very unequally dlsefl6es
ted over the earth's surface. They oGe4f
most frequently in the higher iatituass.
and are almost Unknown within the
tropics. At Havana, in latitude - dSs
grees, but six aururas have been record
ed within hundred years, aud south of
Havana aurOras are still more unfro.
quent. As we travel northward ffoM
Cuba, auroras increase In frequency aud
brilliancy; they rise higher In the hssvs
ems, and oftener ascend to the zenith
Near the parallel Of 40 degrees We and
on an average only ten auroras annually.
Near the parable! Of AZ degrees the ave-
rage number is twenty annually, near
40 degrees the number is forty; and near
the parallel of so degrees it amounts to
eighty annually. Between this point
and the parallel of 62 degrees auroras.
during the winter, are seen almost every
night. They appear high In the heav-
ems, and ~ often to the south a. the
Tn f,,r
are seldom seen except In the south, and
from this point they diminish In fro.
quency and brilliancy ~ we advance
toward the pole. Beyond latitude 62
degrees tho average number Of auroras
Is reduced to forty annually. Beyond
latitude 67 degrees 1t Is reduced to twen-
ty; and near latitude IS degrees 1t h re-
duced to ten annually.
Auroral exhibitions take place in the
upper regions of the atmosphere, since
they partake of the eartir's rotation. All
the celestial bodies have MT apparent
motion from east to west, arising from
the rotation Of the earth; but bodies b.
longing to the earth, incluttrg the at.
mosphcre aud the clouds which float In
/ 1t, partake of the earth's rotation, 40
that their relative position Is not affect.
ed 10y 1t. The same is true Of auroral
exhibitions. Whenever an auroral
corona is formed. 1t maintains sensibly
the same position in the heavens during
the whole period of its continuance, sl.
though the stars meanwhile revolve ae
the rate Of Is degrees per hour.
The grosser part of the earth's atmos.
phcre is limited to moderate distanes
from the earth. At the height Of little
over four miles, the density Of the air IL
only one-half what it is at the earth's
surface. At the height of 80 miles the
atmosphere is well-nigh inappreciabls
in its effect upon twilight. The phe.
nomena of lunar eclipses indicate IN
appreciable atmosphere at the height Ut
66 miles. The phenomena Of shooting
stars indicate an atmosphere at the
height Of 200 or 300 miles, while the
aurora indicates that tho atmosphere
does not entirely cease at the height Vt
800 miles. Auroral exhibitions take
place, therefore, in an atmosphere OF
extreme rarity; so rare indeed that II,
in experiments with an air-pump, W
could exhaust the air as completely. We
should say that we had obtained psr.
! feet vacuum. z.s"....s..- .~
The auroral beams are simply spaces
which are ilIumined by the flow Of elec-
tricity through the upper regions of tho
atmosphere. During the nuroras Of
1859 these beams were nearly 500 miles
in length, and their lower extremitiss
were elevated about 45 miles above the
earth's surface. Their tops inclined
toward the south, about II degrees In
the neighborhood Of New York. this
being the position which the dipping.
needle there assumes: - PRorEssoR
LOOMS, in Harper's Magazine.
The Dayton Ledger tells the following
anecdote, which we can very easily be.
lieve to be true:
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