The New York herald., 1871-11-09
ENCKE'S COEET.
From the London Telegraph.)

From the London Telegraph.)
During the occasional fine nights OF the past few
weeks the "eartnly godlatncrs OF heavens ights''
have been turning their telescopes towards little
region OF the sky defined by the constellation yclept
the Northern Triangle, and have been straining
their sharp eyes to catch sight OF an old familiar
member OF the cometary family who is known to
visit the sun and show himself to the earth every
three and a quarter years, and whose apparent
path OF approach ut the present time 10 the direc-
tion Of the star-group aforesaid. He comes with
great regularity, and he is watched for with much
eagerness, for interest attaches to his appartion
higher than pertains to the coming OF any OF lis
tribe, and little lower than that which Is excited by
herarest ev ents In the astronomical category. And
yet the comet Is not q large one; 1t Is pgmy CON-
pared to the "Donatr' that lit our autumn skies In
1865, and mite beside that great one whose tail
wnisked In 1861 During some OF its visits 1t has
only been visible by aid OF telescopes on other oc-
the naked eye. ana exhibited respectable extent
OF tall
ent sojourn IN our vicinity cannot certainly
isvs that viii well dlseernSs is'S Sy sesS eS
next. Coming, truly 10 time and place, it has al.
according to the calculated increase Of bright
ness, depending upon lts approach to the sun and
epoch just mentioned US it was at the time when
mir. Hind caught the FIRST glimpse or It about fort
night ago. But the calculation may be falsined by
ness due TO the changes In physical constitution or
condition which all comets undergo in their passage
Tns comets interest does not, however depend
upon Its magnitude. Upon what 1t does depend
which essentially dates from the year 1878, when on
the night OF the 10th OF November an energetic OBJ
server. NJ. PoEs OF Marselles searching the heav.
ems for what he might find, detected little comet
OF the ordinary telescope kindthat is little patch
Of faint nebuosty slightly brighter in me centre
remained In sight for about six weeks, and a fair
number OF observations OF its constantly changing
these were made the basis for calculating the form
and position ol the comets orbit upon the supposi
soon found ; inaI such e. 2 curve Of motion
positions, and accordingly the illustrious Encke
set about rigorous analysis OF the observed posi-
comet. Instead OF moving In curve which would
take 1t out OF our SYSTEM perhaps never TO return,
actually coursed along small ellpse 80 small as to
be contained within the orbit or the planet Jupiter,
and therefore not earn ying the comet sixth part OF
the way towards the boundary OF our solar system.
run In the surprisingly short period OF 1900 days.
Naturally, curiosity was aroused as to whether IL
and surely enough, when the cometary "visitors'
booksv were examined, II was found that our comet
was identical with one which had been seen in 1906
by NJ. Pons himsef among other observers and pre-
viously. In l7q5, BY MISS Caroline Herschel, and
again, before this In 1856, when II was discovered
by NJ. Mechain OF Paris. II must have called at In
termedlate times and have gone away unnoticed
Here, then was one Of tribe OF bodies, hitherto
supposed 10 be, like homeless Arabs, wandering
about space actually found to be a settler In our
system; as much at home as the earth or Jupiter
and COMFORTING itself ike well conducted planet.
IL was naturally made much OF. Encke spared no
pains in thoroughly investigating It's orbital move.
ments and the perturbatiOnS which these suffered
from the attracting influence or the planets to
which It's circuit carried 1t. He predicted that Il
would return 10 the sun again on the 24tn OF May,
1872, after suffering retardat0n OF about ten days
due TO the influence OF Jupiter. II came sufficiently
10 Its time to establish the verify Of the calcutta
tions, and astronomers, by universal consent gave
It the name OF Encke's comet, mot only as
In performing some OF the most Intricate and abo.
Tious computations that occur In practical
astronomy but also TO mark the epoch OF the drst de-
lection OF comet OF snort period, one OF no ordf-
nary Importance in this department OF the science"
Enckc devoted himself 10 II IS 70 founding. Tine
research into Its movements became 70 him q
.hobby'' OF the most exalted kind Memoir after
memoir upon mis- Investigations was presented TO
the Berlin Academy, and from these Investigations
came several important results one OF which ranks
OF celestial motions has led. That which we snail
nrst mention had reference TO the weight or 'mass"
OF the planet Mercury, near to which the comet
passed in August, 1886. Encke demonstrated that II
u would on q certain day pull the comet definite
distance from It's normal position. But the observa-
tons showed no such deviation, and the planets
mass Was, therefore, presumably 10 error. Encke
set about laborious calculation OF the weight Of
vaIions Of the comet ct the critical time,
and the result was q showing that the
estimated weight In question was nearly twice az
great as II should be. The mass thus found has
SINCE been accepted though future researches upon