Year: 1873

the large hall Of Cooper Union by Prof c. A. Young Of
Dartmouth College, his subject being " Comets and
Shooting stars" on the stage many prominent
persons. including Prof. WIN. q. Peck OF Columbia Col
lcge and John f. Parsons The lecturer introduced
by Abram 8. Hewitt the Secretary of the Union. who
described the nature of the lectures to be delivered
during The portion of the will
consist OF lectures spectrum analysis, following
which in the month OF March will be lectures on chem
stry and mechanics. The lectures during April will re'
late physiology He then introduced the lecturer OF
the evening as the eminent OF American astono
mers" The lecturer stepping forward was warmly
greeted. The following is the lecture. in part;


THE LECTURE.


The watcher OF tho skies has always before him OBJ
iects OF observation beautiful, wondrous and varied
The constant glory of the sum- the mutabc radiance OF
the moon OF the planets the innumerabie
stars the revolution Of the seasons the alienation OF
day and nighta these the ordinary phenomens OF the
armament. furnish material for continual aumfanon
end earnest thought, the subject matter OF science
truly noble But occasionally things stranger st moro
wonderful and beautiful. appear In tue heavens
Sometimes the lightning oometh out OF the east ana
shineth even unto the west sometimes the rainbow
ia act in the sky as Gods signal OF peace
and promise sometimes the Aurora Borealis
eliminates tho whole vault of heaven with
the fickering radiance OF its manycoored oeamS ana
arches and invests the imperial brow OF Nght WIN lts
beautiful crown OF electric light. sometimes
meteor darts across the sky, and In itS expIo-
sion casts down TO us the strange Haghehts'
by which alone We are put into material connec
tion with the outer universe; sometimes a comet
comes with its burning head and pald train from the
outer darkness gathering magnitude and brahce as IL
approaches the and again recedlng 10 the aoy %
which it emerged. And perhaps among the eAoepiohai
,benomena the comets have attracted the most atten
ton naturally justly, too. They are not IKE new
stars or the more remarkable meteoric showers; and
when they do appear they are not, like rebas or tho
Aurora Boreais transient and unstable 700 AUNT OF
accurate observations yet are they so common as 10
dull the edge of curiosity.


The lecturer then described the Aristotehah theofy
more in detail alluded TO the universal Deiei lh tho
astrological influence Of comets as forerunners OF evil
and to the welknown story Of the bull OF Pope Ca1tus
H. against the comet OF 1856, since known as Haieys
comet Again referring the theory OF Aristotle, the
sneaker said But must not condemn the Grecian
philosopher severely the ground that his theory
"a only tissue of unfounded and untrue hypothesis;
untrue il undoubtedly s but at that time nothing more
than hypothesis possible and the truth se had IL
been known could have been established upon the
basis of fact and observation After speaking at some
length on some Of the beliefs entertained in quite recent
times Of cometary influence in human affairs the speaker
went ON 10 tell of the characteristics OF comets


TIE NUMBER OF COMETS.


Tber number said he, is unknown 1t must be very
great if we include which only visible To the
telescope for time rarely be found when there Is
not one in portion other OF the heavens and often
there are two OF three The expression OF Keper that
great dscoyerer but crotchety philosopher, was that
they are like fishes in the ocean," Indeed, he seems to
have thought that they are like fishes not only III their
numbers but he more half believed them to be4ying
creatures which 20 swimming through the celestial
spaces on their own responsibility Bright comets are
not very common Humboldt states the number OF those
visible to tho naked eye since A. ID. 1900 as follows;
between the years 1900 and 1906 IL between
1000 and 7OO between 1900 and lsOO and l3 since 1900
Since 1850 there have been four three Of which were
very brilliant in various ways remarkable In all
since 1900 there have visible to the naked eye or
on an average, one every q years. If we include
the telescope comets list would mount up TO sew
era hundreds In 1926 alone nve were discovered ana
French astronomer between 1864 and 1885,
and in the breath bewais the loss or ms we ana
ticpated of her Illness Pons In the first "a
years of the century, averaged one year. ana here are
several living observers who have discovered from nye
to ten apiece The whole lumber recorded thus far -
G25 400 of them having been observed previous 10
the 1000 The elements O about 2JO nave Deen C-


Ar the time OF the revival of letters when the system
Of COpernicus became established the subject at once
attracted attention Tyoho Brahe completely over
threw the theory OF solid 3roS by pr9'1g @ from no0h
the earth by many times the distance or the moon
and so ran orbits OF Mercury and Venus as 10
render perfectly absurd theiArstoelan notions Of the
mechanism OF the ARMAMENT III was soon evident tlht
comets traverse the heavens in all directions with
enormous but very variable velocties Tycho supposed
them to in circles about tho sun; but his pupil
Keper finding this TO accord with observation con
cluded still more remotely from the TRUTH that they
move in straight lines little later HeVelus DIS
tinguished astronomer Prussia suggested that their
orbts might be parabOlas or elipses with the sun in
the focus and in 1884, DOrie OF Saxony succeeded IN
proving II by means the great comet Of the preceding
wear The lecturer then described the epse hyperbOla
and paraboa. The first mentioned curve bounds sec
tion cut from cone passing through and at angle with
The hVDcrbOa bounds section parallel To the
axis and the parabOa, section parallel To one OF the
elements OF the cone. Newton, who at the time
of D0rfes discovery investigating the law OF
tatoD, demonstrated that any body whatever of
such nature be subject TO that law must
rily, whenever 1t should come within the sphere OF
the solar attraction around the central orb In
path either eptca parab0ic or hyperbolic OF course
comet moving in a parabOla the length OF which is
finite, could return once having visited the SUM-
and the same would be the orbit hyperbolic
such comet, intercepted by the influence OF the III
the midst Of its journey through the desoate spaces OF
the stars comes darting swifer and swter toward the
great OF life and power. warns itself for all
by the central fire. and then recedes again to those out
skirts where the itself appears like
and where there neither light heat; there
listessy until the lapse Of untold ages brings again
within the Of other sun, which 1t visits
and abandons in a similar manner, hOuseess wanderer
in space. Probably many comets belong TO this class
but undoubtedly the greater number do not There
immense length that hundreds and thousands Of years
consumed In each revolution; and in this the
portion near the SUM- which the only part subject to
our inspection, differs nsensibly from parabola.


THE EABoRs OF HALEY.


The lecturer then gave an account OF the ardu0us
labors OF Haley who, having collected all the recorded
observations comets that could be entitled to any
credit for accuracy proceeded to calculate their paths
in hopes thereby the reappearanoe Of some Of
them. He computed the elements OF a. among which
three from the resemblance OF whose orbits and
the uniformity OF their appearances he supposed were
the same. On this suppositi0n he ventured TO predict
comets reappearance in the Winter OF 1859 II did ap
pear and came its perihelion within month Of the
predicted tme and this month OF difference was due
mainly 70 the attraction OF Uranus and Neptune then
undiscovered planets Encke OF Berlin In 1919 discovered
that comet which bears his moved in an orbit
moro nearly circular than any previously invest sgated
with period Of only three years and half Blea, an
officer In the Austrian army discovered another in 1926.
which has been four times since 1896 -Four other
been discovered TO have periods less than
eight years, but all small and OF little account.
There about 40 Others which have been computed