New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1874-07-10
ACCURICF OF OBSERVATTONSO ON TIE
COMET

STRIKING COINCIDENCE or TIE COMPUTED ELEMENTS
oP THE COMET WITH THOSE OBTAINED IN en-
GLAND-AN INSTANCE WHERE THE EARTH PASSED
THROUGHTHE TAIL OF A COMET AND THE RESULTS.
To the Edttor Of The Tribune.
SIR: In some Of the newspaper discussions
about the comet observe report Of an interview
with two gentlemen well known in connection with
Astronomical subjects. In which one OF them is repre-
sented expressing the opinion that the idea that
have been to compute the distance OF the comet
from the earth all because there are no data
ana the other represented suggesting the posi-
DAy OF determining the comets distance ny lie paIaI
lax since have been uOmlnay the subject OF an h-
teryiew by the same enerprlsng reporter at time
when was In fact at a distance from the city and
knew nothing about the Interview" until l saw the
account Of Il ~ print. readily believe that the
carvoyance OF the reporter more clcaryison OF
the real opinions Of the gentlemen to whom they were
attributed, than II Of my OWL Not, therefore Is
replying to them, for the benefit OF others who may
not be aware u the mode in which astronomers
obtain the. distances OF comets, l snail Stare
that I have this morning received copy
Of Nature, dated June IS. containing letter
from Prof Hind, IN which he gives revised orbit OF
the comet, making the lOgarhm Of its periheion dIS-
lance 9s2955l9 The orbit which l computed June r.
and have used in all my computations published In The
TRIBUNE since. carried only % i've decimal places
and I made the logarthm OF the perheIiOn distance
5.n@s11 lhc oilcf tltnfhts also hslot' oAN" e"''
agreement Of results from different observations aud
by DIFF compuer-. I think viii b3 accepted as an
evidence Of their accuracy.
Prof. Hind states that the "clOse agreement with
paraboNc motion is favorable 10 the identity Of the
with that OF 1891 Notwithstanding similarity Of
elements bus must look to observers IN The south
ern hemisphere 10 enable TO decide this point The
may certainly be there observed until October or
November IN the Antarctic clrcumpOlar heavens"
From the measures u the stated In the article
OF Il. Rayct published IN TIE TRIBUNE OF july T. 1t ap-
pears that the nucleus and surrounding coma formed
body at the time discovery 100000 miles In diameter,
larger than the planet Jupiter and aoOut 1900 times the
bulk Of the EARTH and that on MAY 10 and June while
It's apparent diameter had greatly increased from lie
having approached It's actual diameter remained the
same IL is impossible now 70 make measures Win
which 10 compare these consequence Of the blending
u the coma the tail, having no spherct mass 70
measure. The nucleus stated by Prof HInd 10 De
rather than 1000 miles in diameter
Il VIII undoubtedly crafty many OF your readers 10
the following account OF the carh passage through
the tail Of the o. 1861, which copy from Brande
and Coxs Dictionary Of Science article Comet" As At
that me that comet had been IN the northern
hemisphere no one had opportunity 20 observe lHe
phenomena with scientific accuracy.
This leads MS to mention very interesting crrun-
stance Ia the history OF the comet About the time
the modal passage JIue 2S evening", 70 was renaTheh
that The earth was behind The comet only degrer5 ~
longitude, seen from the SUM- and tIe dller uoJ
direction Of the ta 90 BRING 10 either upon
on very 10 our globe. Accordingly lt was tOuJrc-
tured that with due allowance for curvaiure 10 Vas
quite possible the earth might have oeen involved
OF june 30 Nutu size dIIlFci
AZ tine comet, modal point Or longitude. Observations
subsequently published, which enable Us 10 determine
the true direction the tai with more certainty, appear
10 indicate that main branch was IN advance ol inc
earth Oa that evening, but mat th' secondary
ta. or the dhused nebulosi'y which sepira,
tel from the principal ray, was actually dIi,Clru
nin.ulrre And IL IL remarkable ana significant fact
that not only IN various parts Of EngGnI ana Ireland!
but also IN spain, italy SWz rland, ana other Con-
tiueuta countries, very peculiar pAOspl0rescence or
illumination pf the sky pCIC ptiDie during the cary
hour, OF question, which many persons sup
posed 10 caused by the aurora DOreal- unusual aa
me phenomenon M the summer months, especially lh
the -outu Europe; at the ume 10 was remarked
that the ] mostly Of the Hky AN not resemble the
usual effect aurora, DUt something qultc eX
ceptOnal. We incline 10 attribute the pAtnoMouOh 10
the presence OF cuurtc master Di matter IL can DC
tcrurol iu itmOs IHere." HENRY NJ PAAKHChoE
AeU- YORK; July ., 1854.