New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1881-06-27
WATCHING TIE COMET.

OBSERVATIONS BY PROFESSOR DRAPER.
he SUCCEEDS IN OBTAINING BTTTER PHOTOGRAPHS
WHAT HE EXPECTS TO ACCOMPLISH FUR
THEIR.
Professor Draper succeeded once more yesterday
morning in photographi:ic the coinrt Two impress
sions obtained, of which is Of the size rs it
appears to the eye while the other enlarged fifteen
times. The smaller image, which is the mUre
distinct shows the nucleus and ccr,a with portion
Of the tail 10 the length Of five six degrees The
enlarged figure tloIgh fainter reveals the Shape Of
the coma which. flowing ward from the nucleus
on both sides, gives the comet much the appearance
of a bird with wings outspIead.
"Thc night was hszy," said Professor Draper yes
terday. "but succeeded in getting ffty minutes
exposure which gave q much better resdlt than on
the night before, when the eXposrro wAs only
third as lon, twas between . and , o'clock in the
morning when the Impressions were taken. am rot
exactly satisfied with the result vet and shall
try tonight once more 10 S longer cXposure. Rain
or shine shall 20 down to NY observatory about
midnight and put the instruments in readiness
TO take advantage of whatever opportunity presents
itself. am particularly fortunate in having had
all the necessary appliances in order when the comet
appeared. Had not bccu prepare !, il might havo
come and gone long before | conli have photo
grapbcd it, hut As am cspc tally engaged in photo
u
to adjust the Instruments to the luminary To
photograph a star. We remove the eycpi'cc ~ the
telescope and put the plate IN lis stead. No camera
is needed, since there is no light in The room and,
b,sides the shaft Of the telescope would cut oil any
troublesome rays.
'The analysis Of the substance of the coma. by
mcanso Of the spcctroscop" will hc II even m rc scion
tifc moment than than tn photographs The rpirt
from the Harvard College O'scryaiorv that Tie
nucleus gives a continuous spectrum m, - IS shows
that the nucleus is solid @, hImn n0ov. and
therefore cannot be analy yz'd. The cOIa. h0N r.
* composed Of gas. and will therefore lend i@f 'o
the of the spectrum analysis Th s3ecifim im "I
a comet has never been satisfactorily obtained. Mt
snch imperfect results as have hen obtained iudl-
cate the probable pres nee Of compound of ear
bon in the coma and tail. The nucleus Of Cogga's
comet. which appeared in 1871. gave continuous
spectrum but the coma showed three bands which
resemhlcd very much those Of the hydrocarbons.
The spectrum of carbon itself indeed. is not very
well under tood but the imperfect analyses Of
comets which have heretofore been obtained show
marked resemblance to that of an electric spark dis
charged in olcfant gas which consists of hydrogen
and carbon. As the spcctroscope has been much i'm
proved. / look for important results from ~ ar-
plicatIou 10 this, the brightest comet since the a
peuance of DOnatis IN 1853
How much is already known Of The nature Of
comets tail p asked the reporcr to hon Professor
Draper was giving the infolm'i ~.
VERY little indeed. comets tan
IS one of the strongest things in the
universe. Though millions OF miles IN length q
quivering billowy trelnOr, such ~ the aurora
bOrealis sometimes shows is often seen running in a
few seconds from one md 10 th" othrr The known
laws OF motion inadequate 10 account for ~.
phenomenon. The behavior of the tail Is IN other
respects also very singular. Ii alwaya for example
points directly away from the centre Of attraction
following after the nucleus its approach 10 peri
helOn; and ~ he comet sweeps around the sun n
whskS suddenly about 10 keep the solid part
aIwnVs between iiSclf and thr suu finally
going IN advance ~ the comet i,cedcs. IhlS
popularity has gwen rise 10 tAt st. flOu thai tc
tail might bc merely a kind of luminous shadow.
the sky by the rays Of the san -mun through
"A cloud Ic test this theory Professor lNudali mol
some experiments 10y passing a stream of light
through certain gaseous or liquid Substances. bat
the hypothesis l. hardly enablc. Aside from other
considerations, tine tail OF tins comet Is convex
toward the east 10 can hardly bee negative
shadow Therefore, as shadows are not cufyci. II
is to say what the tail is not than what II is
" What was the meaning OF Professor Swlits
opinion published tins morning, that the comet Is
apprOa, hing tIc sun Z
u | think there must have been some mistake in
the report the comet j. certainly Tccedmg. II *
gradually rising above the horizon and approach
ing the North star, about which, with the rest Of
the heavenly b dies n appears 10 TcvOlyc. II viii
continue To draw nearer to th" pole, growing
fainter aud fainter, until II disappears For few
DAYS however, IL may pos-Ibl, increase IN bright
ness. 1t moves very fast 1t present, passing
over a space of about . every day. IL will
be visible for a good whlc-pcrlaps for many
weeks. II Will not set below the norizon. but
may be seen in fiIr sky from dark 10 dawn. In
the daytime II il nearly overhead. / have uO data
for determining whether thus II new comet or
ia nar one II used my time % observe ~ lno-
tions, should have none left for ascertaining ITS
shape and composition
The comet was plainly visible in the carly part Of
last evening, but about had-paSt o'clock the sky
was overcast by mist which at midnight stlll PFC
vailed.