, 1866-04-28
THE GREAT TELESCOPE.
The instrument in Its Place,

The Instrument in Its Place.
tts Wonderful Power and Perfection
Machinery Of tho Dome and Tube
Professor Stafford - observations or
>frtus-Thc Fnturo of Chicago In
Astronomical Science.
The great telescope Is now In position. and
save lew finishing touches Of adjustment,
IS in exact order for undertaking the securing
process 1t was intended TO subservc. Already
II has been pointed t@0ay at some of the
more prominent celestial objects; soon it will
commence its mission of systematic pecring
into the inflnity, and searching out the solu-
tions TO the intricate problems, which, even
in this age Of advanced science have hitherto
balcd the analytic skill Of the astronomer.
To fatbon hitherto unsounded depths; to
detect variations before unknown; to meas-
nre quantities till now undetermined; to
dissect out conditions which have heretofore
escaped the practiced ken Of the observer,
will bc the mission of this great eye of
science, which, like that Of faith, dares to
peer into the deepest arcana OF creation, aud
throw It's glanccs into the region where the
Eternnl Vas once supposed to sit enthroned
In silent majesty.
'Tis curious piece of mechanism, that
telescope; column which, although Of wood,
and movable In all directions at the touch
Of the finger, is triumphal pillar, which
bears testimony to far greater achievements
than any the memory Of Which has been per-
pctuatcd IN solid granite or polished marble.
It is the ladder which connects Garth with
heaven, Of which Jacob dreamed, but which
We have realized. Tho angels may not liter
ally ascend and descend upon it, but along
that Insignificant, Jet gigantic tube, flash rays
Of bright intelligence from heaven to mortals,
swiit-winged messengers Of knowledge from
the great Omuiscient. In that great matter
key the beams Of light, which, difuscd over
the whole universe, convey but q mere gen
eral information, are convcrged and concen-
tratcd into definite powerful uttcrauce, Civ
ing forth to us the majestic facts Of nature
in language which Our modern science enables
US accurately to interpret. It brings
10 view the handwriting on the
dome Of the ETHEREAL vault; but, un-
like the mystic characters Lcra1ding the
doom Of Belteslazzar, they tell of the COM
ing glory Of the latter days, when the laws
OF the universe shall be "llying cpistlcs,
known and read OF all men,"
We may be pardoncd a dnsh of enthusi-
asm In speaking Of this wonderful instru-
ment-one OF which not only Chicago, but
the United States may be proud, as OF one
Which cxccls any Of the justly boastcd tri-
umphs Of scientific skill evolved by deep
thought and ingenious manipulation among
the Swans OF the old world. Scarcely thirty
years ago, less thnn the brief space of one
generation, the frs: astronomical observatory
WIS erected IN the Cis-Atlantic shore, and
tho Republic Of the West, then but halt
century old. started out in the race Of cxplor-
alton, whose goal is not fixed at mile dis,
tancc, but lies out among the lli1nitablc
depths, and, like the horizon, eterual1y yrecedes
fTo1a the view ofthe seeker. Nobly has she
acquitted herself IN the rnce, taking, In that
short interval, commanding position on the
thinly studded astronomical chart OF the
globe. And if the progress Of the United
States has been rapid, that Of Chicago has
been even more so. At the time when
America entered the lists, our city was not.
waste Oh The prairie, scarce broken by half
q dozen huts raising their heads few feet
above the swamp. WIS all the rudimcnt OF
our present observatory, and the lookout for
indians was the sum total OF the searching
process now extended to take in the ncbulous
systems which appear TO deck the confines
Of the Universe
The case may be thus summed up. The
Chicago telescope is the best in the world
not only the largest, but possessing de!in-
ing power certainly not surpassed, and pro-
hahly not cquallcd, ou this planet. ANY one
who has looked through other large telc-
scopes will readily appreciate the difference.
The most perfectly cast and ground lens,
though to crcn critical examination perfect,
yet has numerous flaws and inequalities which
become painfully apparent in their effects
when brought into actual use, aud, of
course, the greater the power, the more palp-
nhlc arc the defects. That lens, eighteen
and 3 half inches in diameter, should be
60 accurately formed as that q ray of light
striking every point on Its surface ehall be
accurately refrscted through length OF
tWenty-three feet to meet at the same focal
spot,uniting in stream no larger than needle
point is wonirops In the extreme. Indeed,
go seldom is this result attained, owing either
to want OF homogcnclty In the material lin
creased density In any place giving greater
AH"aN%AAE vt"NAy VI ~ A0Nh VI ACEul2EJ III
the outline Of the curved surface, that what
to the naked eye is a luminous dot. becomes
in the telescope IN Irregular 1occulcnt mass
OF light, some such thing as would be
produced on larger scale by throwing
spade full Of soft mortar from q
height Of several feet. So common Is this
that most large Instruments are provided
with m Opaque cap to cover the object glass
and having hole cut In It ecccntrically, 60
that by turning It round the rays Of light
may he excluded from the less perfect paris
Of the gluts when definite outline L
needed. No such cxpcdicnt Is required here
From every part Of the surface the ray d
light there impinglng is truly bent in tue re-
qufrcd direction, and focallzcd with pre-
cisfon which one Is almost tempted 10 believe
Is the result Of fortuitous accident ratle,
than Of years Of labor directed by masters
| skill.
We saw the telescope few daysag turned
on to Sirius in broad daylight. The outlined
form was clear, distinct, broken only by I
! slight trcmor due to M atmospheric wave
The star looked to be about the size Of al
ordinary marble, Parties accustomed to rear
| Of o telescope us magnifying two or NOR,
no largersn The reason Is that the planetary
bodies, being at measurable distances, hay,
! m apprcciable visual angle subtcndlng th,
opposite edges Of tie disc, aud therefore ca
pablo Of increase. IN the cnsc OF the flxet
stars, the distances are SO vast that the sub
tending angle is infinitely small, and there
fore not capable Of augmentation by multi
| plica,ton into finite number. We're It no
that the rnys Of light coming from fixct
star arc scattered in their passage through
!, on: atmosphere, they would strike on th
eye as but single point. Hence, when ,h
/ my is confined and steadicd in the telescope
tuhc, md rays from surrounding objects Gu
of, the star really appears much smaller tha,
when seen by the naked eye.
We would suppose that Mr. Clarke, til
maker Of the glass, and at present iu Chica
go, experimenting the adjustments Of tn
instrument, would feel particular intcrcs
III this siar-the Alpha Of Cauis Major
the "Grcater dog Which he has robbed q
its dog.iu-thc. .nlanger character, by shown!
IL TO have companion. In this fact We l,av
q sample Of the powers Of the instrument
Sirius and his companion arc 20 near togcthe
{apparcntly,) that the angle between them
but about ten seconds Of arc, q value so smal
that its tangent Is hut .00OoiSiS13:i when til
radius is one, OF In other words placing til
apex Of the auglr in the eye, ut the distnnc
OF a mile the aides would have rccedcd fror
cacl, other but \ small fraction over thrc
inches, and but about the onc-hunlredth par
OF au inch at the distance Of 81. yards. Tw
a.