New-York tribune., 1874-07-04
THE MATERIAL OF THE COMET.
sPECTRosCOPR ANALYSIS APPLIED AT THE fA'h
oBsrRyAToRY-TuE TAIL NOT CONSTITUTED oI

sPECTRosCOPB ANALYSIS APPLIED AT THE PAhiH
oBsERyAToRY-TuE TAIL NOT CONSTITUTED Oh
SOLID INcANDBsCEST MATTER.
TO the Il dttor Of The Trt'une.
SIR: The latest spectroscopc observations
OF the present comet are published In the Compe'
Rendus for June g. by NJ. g. Rayet Professor OF Astron
omy az the Paris Observatory. The results and
very important to knowledge OF the p1ysicai cQnst'
tuition Of comets Herewith is translation:
Since astronomers have used the spectroscope In re-
search IN celestial phy sizes no brilliant comet visible to
the upaided eve mas appeared In the portion OF the
heavens that they are able TO explore; inc proolens
merous need only cite the exact measurement OF the
lengths OF the three bright bands Of their spec,
OF the bodies TO which they belong All comets which
become visible to the unalded eye, II Is important TO
study and watch while visible In tue hopes OF dlsc0y
The comet discovered at Marsellles by NJ CoRgia on
the OF April II will probably become brilliant
have conseq uently studied its specfra with much care
and here present the first results OF my observations
At the time Of discovery comet very faint and
of circular FORM with a central condensation very
marked forming Luminous point, the diameter OF nebu
losity being two minutes The light faint IL
was difficult perceive the existence OF spectrum.
Since then the comet has been continually approaching
both the sun and the earth and its brancy regularly
increasing. On May 10 made with NJ. Wolf the first
spectrOscOpic observation Tue comet was ten
three minutes in diameter aud was forming tail. Tne
light seen through the spcctroscope gave continuous
spectrum from the orange to the bue spectrum OF
OF gaseous nebula). This spectrum is well recog
Dzed III comets, but 1t differs from theirs IN It's dlmen
siOns aud IN the relative brancy OF the different por
tions Tnus while the continuous spectrum OF the
cleus is general large ami dnuse it Is IN M Coggia
comet very Moreover the luminous bands, in
stead of DeiDg sharply defined the side the most re-
glbe terminated both toward the red ana the
violet by fine lines. This fact especially prominent IN
the middle baud, the longest and most brilliant was
striking 1t is the first time have ascertaned IT,
New observations made on the nights OF June 4
and g. will only mention the second, obtained under
favorable atmospheric conditions Then the comet had
round very bright nucleus Ut being equal TO star OF
about the eighth magnitnde its edge sharply defined by
surrounding nebuosty The position Of the nucleus
could be observed with the same ex9ctness as that OF
fixed Tns point surrounded with nebulous en-
eylope OF about four minutes IN diameter It's brightness
regularly from the center TO the edge. This
envelope prolonged on the side opposite to the sun
into a tail a distance OF eight minutes from the nl
cleus brightness OF the comet (Which about four
times greater Than when discOyered) must be cOnsid
cradle furnish 50 bright spectrum Tue continuous
spectrum corresponding TO the nucleus IS remarkably
narrow almost narrow as that or star seen In the
same instrument. 1t recalls the spectrum OF star OF
the sixth magnitude, but without color towards the e1
The spectrum Of the bands IS composed OF three
lines which from their refrangbiity, found In the
yellow the green and the blue Tho central band Is
long and bright, and when the slit Of the instrument Is
properly closed i Is terminated both toward the red
and violet by sharp narrow lines. There Is nothing
of the appearance of snadug toward the violet that Is
noticed In usual telescope comet When the ltght
Of the comet becomes sufficient slit be
VI % 49, rToy t rerbo ps will be possible to reduce
IL "A bright line. The yellow ana the Dlue Dand nave
a brIlhancy OF about half the other, and they are
little duse toward the edge approaching the ordinary
type. A., ia. -, 49,. .o.
across nucleus 10 obtain al once the pecra Of
the nucleus and envelope. the slit Is placed across
the tail spectrum OF three bright bands Is seen. as
already described, without however trace OF continu
ous specrum aud each separated by dark intervals
In there therefore, no SOLID incandescent ma
terial sensible Quantities. o. 3.
Dudley ObSerrat0ry Albany. N. T. July 2, 1874