The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1859-01-26
Lecture OF Professor q. II. Mitchell ON the
Telescope.

Lecture OF Professor q. II. Mitchell ON the
Telescope.
Last evening Professor Mitchell delivere~ S,u.,.
leresting lecture on the telescope, th 49,.
Tho building was crowded 10 exess and Pc ,s.,nr. MA.
received with great applause by IN hit seu. and ammo.
ciative audience. y, add
<nieus placed biz sun In the centre, and when
.<r pRcnaulgated his mighty laws, II seemed q II the
problem Of the starry heavens could receive no further
solution The human eye is the most wonderful instru
of which we have any knowledge It's beautiful con-
structon and the distance reach are marvellous;
but its power has limit beyond which is darkness, and
nothing for It's keenes vision. Before we can 60 beyond
this limit therefore, one Of two things necessaryeither
60 outside, and, soaring into the depths Of
space mark the heavenly bodies beyond the ken Of
his naked eye here EARTH he must In some way bring
down those orbs from their spheres How hopeless the
accomplishment Of either How can man lift himself up
to the heavens and behold revolving worlds in close
proximity How his short and puny arm bring them
DOWN. Impossible. But when human genius is excited
by great objects, IL seems 10 elevate itself in
proportion and nothing is beyond Its grasp When the
eye could further genius prepared an instrument OF
such wonderful power reach immensely far beyond 1t
the telescope instrument with which all now so
familiar that apt to underrate its capaby. But
if only had such instrument to aid the other Senses
what would be the result? II, Tor instance We had
instrument Of proporonate power for the we could
hear from this spot the debates in Congress- at Washing
nay could hear the speeches made in the British
Parliament But who could attempt to carry the human
senses beyond the limits God has assigned thems Yetit
scope the instrument by which the wonder wrought
In the Guardian Nights read that he who placed his
foot the enchanted carpet could be instantly trans
ported any spot he wished he who places his eye to
the magic tube OF the teescope transported at into
the heavens, measures the moon and the inequalities
its surface, and wonderful STILL goes from planet to
planet till he penetrates to the outside Of system;
and hence arithmetic cannot compute the distance,
even thought grasp The lecturer then prosecuted
point out the difficulties to be commended with The OBJ
server located globe which not stationary,
but revolving at the tate Of thousand miles hour
its own axis, and travelling at the same time around the
sun with speed Of CT 900 miles hour then there
difficulty to determine some point absolutely fixed by
which to ascertain the distances and motions Of the hea
veny bodies But he would be asked why not refer TO
the fixed stars? His answer was that the fixed stars
were not fixed The telescope had discovered that not
solitary one was absolutely fixed In order to fix
point two elements necessary, like latitude and lon
gtude and these the verna equinox and the North
pole, but both these points continually shifting, and
Il necessary to make allowance for their variations
which were even not uniform but Of great completely
When star vas exactly overhead, determined by
transit instr uent 1t was then said to be in the meridian
and every hour and minute 1t passed. that minute
called much right ascension For instance, hour
and ten minutes after passed overhead called
hour and ten minutes right ascension. BY another nstru
ment its polar distance found, and thus its place
The heavens was calculated These difficulties being
ered there to place the instruments exactly horizon
vi OF eAtCty perpendicular, ana IL tncy COuu DC 30
placed to keep them in their position. The instruments
continually shifting The telescope did not retain it's
exact fguret was ever changing by change of temper
re These errors multiplied in proportion to the decacy
Of the work But, again; suppose the instrument per-
fecy adjusted tho light is bent from it's linea direston
by its own velocity and the velocity of the earth meeting
each other The ray is, as were thrown off the track
Further, the observer is not in the CENTRE but the
surface Of the earth; and therefore, must see heavenly
body at different angle from the true This the
ecturer illustrated by locomotive and any particular
in forest through which passed both the tree and
locomotive shifting their places in reference to tho other
rees, as the train moved on The earth, too was not
moving with uniform velocity-it was nodding as il
eere-and the North Pole not where il might be ex.
ected Thus there was complexity upon compcxty All
hat science and Skill and ingenuity could do was exhaust
on telescope instruments; but the chief ingenuity
as employed in the construction Of the pvos great
welve years ago he had been at Munich, and had
cen one OF these pivots in n wondrous lathe, with
nc WI worsmen employed upon It 50 fine was the
old it was the point Of diamond. He saw coming CT
he steel shaving as thin as SPIDERS web. But could
perfect cylinder be madeY He answered no. When the
instrument was mounted and science had done all tina, II
'oud do astronomers had begin where the construc
ors had left Off, and TO determine the variations of the in
rumen by appealing to the stars themselves So with
he division OF circle into degrees minutes and seconds
% an instrument Astronomers had to begin and calculate
he errors OF the instrument and then, and till then
0uld they apply to the observation Of heavenly bodies
Then there were the magnificent equatorial
II which he had not time to give description tonight
Dut would proceed rather TO show what the telescope had
and he asked the audience to accompany
lm TO the celestial regions that they might see tho space
penetrating power OF this magic tube In order to deter
nine s power, be must Tx upon unit, but could
lot be mile, for that would be Of use. He must
axe the velocity Of light, which was found TO be
rst accidentally discovered in observing the sateI
ties OF the planet Jupiter aud their shadows
md this led him to another problem Of greater grandeur
ne distance OF the fixed stars To have idea of this
II them consider that the earth at part its orbit ia
wo hundred millions OF miles distant from what il is at
mother part and consequently its axis must point to
fVyn hupur oft mill
istan from each other at these two periods and vet such
the distance OF the fixed stars that the axis of the earth
YER appears to point TO the same spot the two hun
red millions Of miles shrink into point Not even with
he telescope can it be appreciated Thus we get some
lea Of the distance of the fixed stars The lecturer then
rent on to describe the neness Of the instrument used TO
point Across the glass two threads OF SPIDERS web
ERE drawn at light angles The point of intersection
naoed the observer to fix point in the heavens. When
sald SPIDERS web he meant no poetic exaggeraton
was literally 60. Astronomers had to appeal TO the
pder TO fix point and the spider gave them its web
iarked down by touching Geographic key 10 the
ne thousaDeth part Of second. He looks through the
ibe, and visual ray shoots upn six months he looks
gain to the same point and another ray shoots up The
arh is two hundred millions Of miles from the place
here it was six months before Surely these two rays
Dnverge They do converge, but the conveyance can
OF be appreciated and there nothing to show that thew
re not absolutely parallel The lecturer then referred te
ie experiments of Herschell who by his telescope, had
aked eye, and the abors of the German Hessei who
another instrument, had determined the distance he
these vnary stars or suns revolving around com
ION centre OF gravity He took star sixty one in the
wan, and by its means determined the distance of other
ars Light takes Eve hours to travel from the planet Nep
Inc 10 the EARTH but from the the Swan ten years
cross the mighty gulf Of space. Now TO come 10 the
escope, in the Improvement Of which Herschel led the
ay The naked human eye could stars of the sixth
BY Herschels telescope it could sec stars
300 times further distant By regulating the power of
Is glass he discovered 500 fixed stars in perspective
lch distant far from the other as we are from the
eares, till at last his eye rested the dark space with
~ STARS or light and black as night the glorious orbs
inning from IL like 80 many diamonds. The light from
e most distant of these would take 5000 years 10 reach
&c observer But this not the furthest extent 10
hch the telescope reached Lord Ross had resolved the
'bul@ in the milky way, and found there stars SO dis
ut that required 900 years their light TO reach
e earth There is no end 10 the inntude Of the stars
I'd unverses Of God.
ius Tor the Construction OF the Machinery |
OF the New Sioops-of- War.
RICE sIooP AT PORTSMOUTH, N. III ,000 HORSE POWER