New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1850-08-23

An interesting and important paper on the " IA
rora Boreas7 was read before the general session
Of the Association yesterday afternoon BY Prof. D.
oLmsTID Of Yale. The following is an abstract o.
the points constituting the theory which he adj
vapces:
THE LATE PERIODIC VISITATION OF The
AURORA BOREALls. 49,
Prof Olmsted said the leading objects OF tns
communication were let, To establish me tct
that we have Just passed through an extraordinary
period OF Aur0 az 10 which he wO0ld venture -
give the name OF VisitstIons, which conmencedln
1877 and closed in ls4e. I'd, To determine the
ehafActeristios by which these exhibitions OF me
Aurora differ from toe ordinary exhibitions OF zoe
same phenomenon aDd TO place on reco1o 4 iu' aou
accurate description Of several OF the most
able "a materials for comparison Ia iatofe vlslta'
rms Sd. To establish, by an extensive collation.
Of obsefv atoms the la VS. Of the Aurora BJealls-
ith To determine the origin Of the Al ora, aud
10 assign the tr 40 causes Of the phenomena- Inc
PToe ssOr proceeded 70 demonstrate that during tne
period called q Visitation the Auroras greatly
exec ed the ordinary exbl 0it1nE OF the meteor Ia
punberr, ia splendor, in peculiar combinations OF
Erms, and 10 Progression which works begin
ming. middle and end
The laws of ste Aurora Bore Ais, as deter nioed
BY an extensive induction OF facts chiefly gathered
from personal observations, the Professor showed
TO be the follow ing, comprehendiog both such az
are generally admitted to DO the leading facts or
laws, and such as are deemed somewhat new, or
at least not universally received and established
truths
/. That the Aurora Of the first class usually
near the end OF evening twilight, 10 the
form OF q northern light, resembling the dawn
that il usually arrives a. lts maximum at all places,
however differing in longitude, at the same part OF
the night namely, from 10 10 IL oclo3k, aud more
frequently little before IL AID that Autorss OF
the highest order frequently continue all night
while those OF an ordinary character commonly
ended before midnight.
2 That great Aurora 10 usually preceded by
large bank, or cloud Of peculiar UapOr, differing
10 It's nature from ordinary clouds, commonly ex-
hibiting milky appearance, but so netimes OF
smoky hue or the two mixed together; And mat
the extent and density OF this aurorsl vapo', rest
ing upon the northern horizon, form the best prog
nostic we have Of the probable intensity oil toe eX'
hlbition which is to follow comprsiog the material
Of which the successive forms OF the Aurora are
constituted.
.. That the auroral caUes, when pecul ariy grand,
mske their appearance later than the streams and
arches, and usually later than the corona, continue
to later hour Of the night, appear at loaer level
than the streamers, AMI roll upward, 10 tue direc
zion Of the sneamers, toward the point OF general
coDcOurso.
T. That aurora exhibitions OF the higher order
are commonly Of great extent, spreading over no
ipccnsiderabie part Of the earth's surface, and
s. That aurOras of the hrst class have three as
tinct forms Of peri dicity-a diarHaf Perlodicuy'
CONNIE noiDg, arriving at the maximum, aud endlb5
at different hours of the night as already asserted;
an aasB0l perodicty, rarely or never ociarflns Ia
June and Lhe greatest number OF the highest order
,lustarng about November these last bearing
.trikips resemblance 10 eson other; AMI secular
per,odcity the most remarkable OF al, recurring ia
Great seIies which have demo III ated " az ora
yi.itstiors" That toe vistatiOus most marked an1
- ..aAn aN a ~
recarine from the middle Of one period % the m'i
de Of tho next period aud last from 20 70 % years,
mailing the interv al from the end OF one 10 the be-
ginning Of the next about - years
That while the iorus of the AURORA usually ap
near 10 be under the control OF mag Retic fJrcs yet
his i. rot always the case since the arches do not
slvsys Gu inmate in the magnetic meridian nor 90
they always place Themselves at right angles 70
the magnetic meridian. nor does inc effect on the
needle CORES pond to the different states oi lhEehs
~ OF the Aurora ,.-i
7. That the Aurora has remarkable geographical
relations, belonging chiefly To the higher sIta les
and only 10 the great Visi.atons descending oeioS
the l.iiiude Of 40 degrees; but deScenilng vel
on the Weaten THAI on the Eastern continent
and pre- vaihog more in the Northern than 10 the
Southern hemisphere
These seven propos tons being shown to be 10
the pre.ept state of our Eledse, the Laws OF Ihe
Aurora Boreahs the Professor proceeded 10 rs
sisn it's true origin aud the cause OF Us mysserlou'
phenomena. .
After the phenomena o. thunder and lightning
were first prove py Franklin u be caused by Eec
6ci,y, il was taken for granted, almost wishod'
di.cas,ion, that the Aurora Boresls was prodac 80
by the same agent; and this hypothesi' has SIT
very nunerous adheren,s. PrJi y mated vent on
10 show that the Aurora is MOI produced by ec.ri
city; frat that il unsafe 10 predicate 81 identity
Of origin for aresemban ce bet Eeen tue Aurora ssd
certain appearances Of Elecuicity in passing
through an exhAuster tube, aud that the ress IN
hlspce Itself is greatly Ogerrated. Security, tha
suoh an origin is Inconsistent With tho great OK
tent Of the phenomenon. Tniroly, that tho cleo
trometors do not indicate the presence OF az
Aurora Fourthly, that these exhibitions sr'
scarcely known IN the Equatorial regions where
electricity 10 most abundant and prevail most Il
the Poi ar regions where thunder aud lightning ar'
unknown. Filthy, that this cause Is Inc lmpeten
TO account for the a0rorsl vspOr, zoe mtsIA
the Aurora itself Finally, that elecsriclsy 10 10
adequate 20 account for the periodicity Oh tn'
Aurora if noS entirely inoonssssnt Win the see0iA
periodiciiy.
Bat Magnstisss has more claim than Electrity
be copIidersd as the trae cause OF the Aurora 80
reals since IL 10 acknowledged that the forms sn'
positions " hich the stresmers, the arches and CO
rons assume, are Intimately related 10 1sSnetsn
and thAt the Magnetic needle itself confirms aa-
tu.blishss this relation. But this proves merely
that the matter ofthe Aurora has magnetic proper
ties but decides nothing with respect to ths ofisln
ofths Aurors which is the principal thing 10 be 40
oosnted for; while Magnetism, like ELECTRICITY, a
tao.qaate to account for toe extent for the light
for the motions for the material, aud especially 10
the periodici,y Of the Aurora.
Dissati,Ged with the attempts which have beer
made TO account 70, the origin or to explain the Phe
noneDe Of the Aurora from either Eectrisy or lag
Detisu, or nom any other cause OF terrestrial ma
ture, we next look 10 the planetary spaces and ar
rive at the conclusion that the origin is eo,UsieaL-
The Professor argued The c,spoic.l orisin of the
Aurora frst from the ertsat Of the exhibitions
which Is greater than could Arise from sny terres
trial carnations or atmospheric pseciptstlons -
Secondly, from the ee4Oe4.y Of the motiIns y hicl
are too great for any terrestrial forces Tnirdly
from the occurrence Of the different stage, of A.
Aurora the beginning maximum and end Al In,
,Gme sOsr Of the night, in places differing wi1el,
m Laneltuic which inhicat ss m AZ snnca..iua -.