National Republican. (Washington City (D.C.)) 1872-1888, 1873-10-27

-" ".cfoscoHfc pnutoRrbpn, ilegiDie W
he naked eye, at the distance Of some four
hundred feet. Had an opportunity offered,
We might have read a love.lctter otef young
ady's shoulder half q mile away. Artificial
loublc stars one third Of q second apart,
we're clearly separated. In hands Less Sc
Tcrcly critical than those Of makers, II would
, n. passed a. OFFICIALLY perfect. Nevsr,hs,
i was not Till October that IL was reported
finished and the payment then due requested.
The influence Of temperature on is figure /
was now quite perceptbls., In the evening,
while temperature was failing, the defect 81
spherical alteration was one way, but after |
u became stationary the defect was slightly |
In the opposite direction.
THE TELESCOPE
Is by no means finished with the glass. The
latter must be carried In one end Of the tube, |
as large as good sized steam boiler, and
ease and celebrity IN any required direction. |
Tue observer must be able 10 tell, at any mo-
meut, the direction In which IL points with |
oxtreme precision. II must admit OF being
moved by clock work In such way that as
the earth rcvolves from West TO East tho tele-
scope shall rcyolve from East to Wet with
Steadily az ai The sa sno ss s0 Sas d the
machinery for attaining these and multi
tude OF other objects have required a large
amount Of thought, continuance, and calcula-
ton, aud II Is only after the expiration Of an-
other year that everything Is complete.
TUE BUILDING.
The construction Of q building In which n
telescope Is TO be placed Is second In import
anco only TO that Of the instrument Itself,
from the fact that defects In the structure
may seriously interfere with the efficiency Of
the instrument. The sole object Of the build
l..
against wind and weather; In all other re-
spccts Its Influence Is positively Injurious.
Tho reason Of this Is that currents Of warm
and cold air around q telescope interfere
with seeing by keeping the object observed
In n state of continual agitation. In erecting
the dome for the great Washington telescope,
no architect was employed, tho plans being
prepared by competent engineer and
draughtsman under tho immediate direction
Of the astronomer, and the work being ex-
ccutcd under the general supervision OF the
latter. The floor Of tho dome Is on the same
| level with the ground floor Of tho main build
Ing and Is therefore very easy OF access; the
walls, above the floor, arc Of heavy oak tim
Der, covered with thin galvanized Iron, while
the dome itself Is Of pine, covered In the same
way. Although Of forty-onc feet Interior
diameter, II can bc turned round by one man
In about three minutes, the machinery for
| this purpose being the simplest possible.
Owing 10 the small amount OF material In
the structure, II will DO easy TO secure the
requisite equality Of temperature, while there
Ia no building below to cause currents OF
warm air. The only corresponding draw
back Is that portion Of the horizon Ia cut
| of from the sweep Of the telescope, but as
astronomical observations are scarcely ever
made near the horizon, this Is not serious
matter.
To all the other advantages Of this style Of
| bail Al al lat % Thu
total cost Of the tower, dome and foundation
for tho instrument, including three rooms for
/ the use of the observers, was about sl4,OO0,
and the price VI the instrument Itself being
about SlS,0 900, the entire cost Of building and
telescope will be about ca, 900. Ono or two
thousand more may be expended In complet.
Ing all tho arrangements, but this will be all
The first question the public always ask
about great telescope Is chow docs II com
pare with Lord Roses telcscopcl" The
question whether the great Washington tcle'
scope will prove TO be the most effective yet
made Is indeed Of interest, but the compari'
sou Is not to be simply made with the telc-
largest, has not proved the most effective.
II we cannot Judge the real power OF DIFF
| fcrcnt rejecting telescopes by their size, II
must he much more difficult TO compare the
new Washington telescope, which Is re
tractor, with theso great retectors. A com
parison of what the Two classes OF telescopes
ought, theoretically, to do Is Indeed quite
easy, and simple calculation will show thai
/ our new refractor Is theoretically equivalent
i to n rejecting telescope Of about three feet
/ aperture, which Is much less than that Of the
great rchectors Of Rosse and Lassel. There
fore the rejecting telescopes have, theoreti'
cally, the advantage, because II 10 so much
more easy TO construct a large reflector thar
n large rcfractOr. But, In practice, the
former Is subject to several drawbacks, the
most serious Of which arc tho difficulties o.
keeping every part Of the great mirror IL
perfect polish and In proper figure.
The result Of these drawbacks Is that grca
rcfoctors have seldom proved efficient II
regular and continued use, and II Is not q
will show anything ever seen by any othe
Instrument. That II will be capable OF dolnt
more steady work IN the measurement o
minute objects, and In the gauging Of thu
heavens, than any other ever made, we d.
not doubt; II IL, however, necessary that II
owners, tho people Of the United States, shal
allow their astronomers the uninterrupted
use Of II. As only an Insignificant Fraction
Of the entire people can see II under any cir
cumstanccs, II Is expected that the masse
who cannot sec II will support the astrono
mers In their resolution TO allow no ono els
to look through It, especially when the,
know that Its use as general gazing instrl
mcnt Is entirely Incompatible with Its use II
advancing astronomy. II any arc thus dis
appointed, they must allow us to consol
them with the assurance that most Of the oh
Jccts at which the public wish TO look, sucl
Us the moon, Jupiter and Saturn, can be CON
monty seon us well with small telescope q
with large one.
ARRIVAL or THE TELESCOPE.
The Junior members Of the arm, namely
George ID. and Avian Clark, left Cambridge
J port with the telescope few days since, an,
arrived In this city on Saturday. Tho instru
ment and material are all landed safely q
the observatory, where operations will be i'm
mcdiately begun TO mount the telescope i
the dome Of tho now building provided for II
reception, which is situated Just south Of th
old observatory and separated from It by th
, computing room, bed and bathrooms for tn
observers. The building is considered to b
as nearly hrc-proof as Is possible 10 make
in accordance with the scientific principle
on which II has necessarily been built.
. The machinery for revolving and pointln
the tower and telescope is pro yided by Mc,srs
Clark II Co., and will be driven by water
power.
We congratulate the American people upo
the possession OF this the largest refractin
telescope In existence, and trust that no accl
dent or detention will prevent Its manufac
, turers from succeeding In mounting Il With
! the time estimated, (about one month, an
that It's revelation Of the heavens TO the ey
,, OF the scientist may soon herald the discover
Of new phenomena which shall serve 10 csyv
the names Of maker and observers more I'm
pcrishably on the scroll Of fame.
Delicate ssrsical Operation.