The Idaho world. [volume] (Idaho City, Idaho Territory) 1864-1918, 1874-07-18
THE Co1uIr.


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Henry r. Parkhurat contributes sons stsrt
ling news about the comet to tho New Yor1
1}3bwHA He proDouncee u tie most wonder
full and instructive comet 10 the history Of th<
world. and predicts that il will excel Donate
comet In spiendor. But tho prospect that ID
tail will envelop the earth has great interest
for tho scientific world, % many problems Ia
tho constitution Vt comets will thereby b set.
tied.
ON tho 14th Of July tho head Of tho comet
will have reached tho horizon in the northwest
at the end Of twilight, % that it will not easily
be visible after that date; but the tail will e.
tend nearly to the pols-stsr.
Donati's comet had . retroGrade motion,
and when the earth met it and the tail was
most brilliant. il was placed yearly st right a.
Giles with the. line Of vision. On tho other
hand, this comet. whose perihelion distance il
very little greater. coming just within the orbit
Of Venus. moves in the same direction with
tho earth, and nearly with tho ssme velocity
(reduced 10 the plane Of the equator), in con.
sequence Of which tho tail, which 10 now near
gradually turn toward 10, still apparently
pointing nearly in tho Same direction. It will
be remembered that D0nati's comet was
curved like soldiers plume; but C0ggia's 10
now and will remain nearly straight. because
the curvature 10 directly from 10 and therefore
imperccptible. Another striking difference
from the tails Of comets generally 10 that it
will be 90 f0resh0rtcned 10 ~ be remarkably
wide at the end.
On July 10th the tail will extend far beyond
the polo and dev-l"p new Characteristic. t..
pering of rapidly toward the end. Within
three or tour days aft~r the 10th. the tail will
have become % expanded in the neighborhood
Of the pole % II GIL . large part Of the north.
ern heavens. Yet it will not b. . conspicuous
object. because it will be % faint % 70 look
rather like IN Immense cloud or . new milky.
wav than what it really 10. By this time We
shall have solved the question whether the tail
10 hollow or has rsdiated structure, or what
10 its constitution.
OF the way 10 which this will end. it 10 not
safe yet 10 speak with di6riteness: for a.
though. if the tail were straight, We should b
almost certainly near the middle VI it On July
Goth. yet ito curvature will probably delay it
two or three days. and even until the earth has
paced beyond tt path Taking the best value
can from previous comets, should expect
the earth. on July ed. 10 Do wholly within the
eastern edge of the comets tail: and will ~
sumo this - b. the case. TIE comet will then
disappear 70 us: but then the inhabitants Of the
southern hemisphere. who may DO ignorant ri
the causc Of the luminosity Of the evening sky.
will see it gradually rise and pass away. and
will be- amazed BY the sudden apparition OF .
comet of Extraordinary sire aud unusual brilliancy
which will burst upon their vision ~ unforeseen
a. the comet of 1851 The gradual diminutios
and FINAL disappearance Of the comet will b.
30 nearly the convcrs~ Of what We shall have
witnessed here that it needs no Description.
What will be the effect upon the earthf II
dare not predict the effect upon the minds Of
men, especially Of the ignorant: bat do not
anticipate any apprrciabl- physical effect fur.
Their than ps.ssibly electrical phenomena like the
aurora IL will. "f cours~, leave ~ s.'me of
ito atmosphere when i, departs. but probably
not enough to affect the barometer. or to come
within the cognixance even of scirntists. But
there may be. BY possibility. one permanent ri.
i.ct Of scientific intrrrst and curi"sity. II the
Earth should not entirely escape, the mossn will
also probably be involved. and il will also re-. |
tain portion Of the cometary substance. A.
the amount Of the stmospherc upon the moons
surface 10 now % email. IL. indeed. there 10 any
u ~. tuat " - uuteCsS&usxautc W VIC utSess
scrutiny. perhaps after the passaRc
Of the csmct we shall End that hencrforth the
NOM will have an atmosphere. Of greater or
lees density. which will materially m"dify the
phenomena Of OSCILLATIONS and solar rclipses.
! will add that Venus 10 safely out IL the way.
10 that the transit expedition will not be inter.
Tered with BY the great comet Of 1874.
f. Colbert writes to the Chicago nihxxe
that the comet 10 evidently developing double
Tail, ~ shown by the streak ot greater bright
ness which lice little within the boundary ot
The appcndage This extra luminosity proves
that the tail 10 shaped like hollow cone. and
10 not solid. He estimates that on the night Of
ruesday. tho I'D Of June. the comet was g..
DOC. 900 miles from the sun and $4,000. 900
from the earth. The fact that comets contain
but email quantities Of matter, a. compared
with thu earth and the larger planets Of the %
lar system, 10 proven By the fact that the comet
does not change tho orbit Of tho planet
when 10 such . position that the planet does
cause great change in the direction Of the
comets path. And the spectroscrope has re-
cently led astronomers n infer that even the
head Of the comet 10 only . volume Of glowing
Gns. But there 10 no warrant for the favorite
dea Of Astronomers that the Meiskt Of . cum.
et might be carried in ones vest pocket. A
globe Of hydrogen gas, which 10 the lghtest
Ras known to us (if we accept tho hypothicsl
Abaron), II equal IN bulk to the earth and Of
The same density ~ that ct which the gas 10
1t the earth's surface. would contain
,ne part In 81 900 Of the quantity Of matter
10 the earth. Now, We can scarcely
"a A ana