The Express.
London, England, 1852-08-24 00:00:00

GIGANTIC TELESCOPE AT WANDSWORTH_

COMMON:

The construction of a monster reflecting telescope
by the Earl of Row constituted fur a considerable period
• prominent topic of interest and conversation in the scien-
tific world. The patience and perseverance of the noble
projector under every kind of discouragement, and the un-
wavering faith with which, at a large outlay to himself,
ho prosecuted his enterprise to • successful conclusion,
! secured to him the admiration sod esteem of all who took
an interest in the higher department of science, while the
discoveries that have since been made through its in-
strumentality have amply borne out his anticipations and
rewarded his exertions. It was necessary, however,
that something further shout be accomplished. To those
nut conversant vath the subject it may be necessary to
state that a reflecting telescope on a large scale must
always be a work of exceeding difficulty, and comparatively
limited utility. the possibility of constructing an achromatic
instrument of • power equal to Lord Rome's, and through
which the object looked at could be directly magnified (as
with an opera glass), has long been considered extremely
doubtful in fact, beyond the reach of mechanical and opti-
cal appliances. '1 his desideratum is, however, now on the
eve of being supplied.
There is at present in course of construction on Wands-
worth-common, a singular-looking structure, consisting of •
plain tower with • lung tube slung by its side, surrounded
by a wooden hoarding to keep oaf intruders. This large
tube encloses a new minter telescope on the achromatic
principle in process of construction, under the superintend-
ence of Mr. V. Unseen, F.R.S., for the Rev. Mr. Craig,
vicar of Leamington. The sate, consisting of two acres,
has been liberally presented by Earl Spencer in perpe-
tuity, or so long as the telescope shall be maintained.
The central tower, consisting of brick, is 64 feet in
height, 15 feet to diameter, and weighs 220 tons.
Every precaution has been taken in the construc-
tion of this building to prevent the slightest vibration, but,
if any disappointment is this respect should arise (which,
however, Mr. Graven does not anticipate), additional
weight can be obtained by loading the several floors and
the most perfect steadiness will be thus ensured. lly the
side of this sustaining tower bangs the telescope. The
length of the main tube, which is shaped somewhat like a
espz, is 76 feet, but with an eyepiece at the narrow end,
mad a dewcap at the other, the total length in use will be
86 Mt. The design of the dewcap is to prevent obecuration
bets eesidensation of moisture which takes place during
fas *pie, when the instrument is most in use. Its exterior
is of MVO metal, the interior is painted black. The focal
daises* will very him 76 to 85 feet. The tube at its
greatest eiramahrome measures 13 feet, sad this part u
about 24 feet from the selsoct.glass. The determination
of this point was the result of repeated experi-
ments and minute and careful calculations. It was
essintial to the object in view that there should
not be the slightest vibration in the instrument.ll
Mr, Gravatt, reasoning from analogy, applied the pin-
eiple of harmonic progression to the perfecting of ac nutria-
meet for extending the range of vision, and thus aiding
, astronomic research. by his improvements the vibration
at one end of the tube is neutralised by that at the other,
and the result is that the utmost steadiness and precision'
is attained. The ironwork of the tube was manufactured
by Messrs. Rennie, under the direction of Mr. Gravatt.
the object-slimes are also of English construction, and
throw • curious light upon the manner in which an en-
lightened commercial policy has reacted upon and promoted
the advancement of science. Up to a recent period the
flint glass for, achromatic telescopes was entirely of foreign
massfactam. &nee the reduction in the duty great 3111-
I,IIWOMMitn have been made in this department. The
makiss of the large flint glass was intrusted to Mr.
Cllemse, of Birmingham, who at first hesitated to menu-
fasten ewe larger than nine inches in diameter, Upon
brim grind, however, by Mr. Craig, he has suc-
' 'NM producing cue 24 inches • perfectly clear,
and homogeneous in structure. Besides this, there is a
sosead ef_ylate-glase of the same dimension, east by the
Thames Plate Glass Company, either of which the observer
may nu et his option. The manner in which these object-
gloms see fitted into the tabs is a marvel of artistic inten-
tion. By means of 12 sonws, numbered wording to the
hours of the day, they eau be set in an instant to any angle
the observer may require, by his merely calling out the
number of the screw to be touched. The object-glasses also
move round in grooves to wherever it may be considered
that a more distinct view can be gained. The tube rests
upon • light wooden framework, with iron wheels attached,
sad is fitted to a circular iron railway at a distance of 52 feet
from the centre of the tower. The chain by which it is
lowered is cable of sustaining a weight of 13 tons, though
%be weight he tube is only three. Notwithstanding the
immense size of the instrument, the machinery is such that
it out move either I. azimuth, or up to an altitude of 80
' degrees, with as mush was and rapidity as an ordinary tele-
sups, aad from the moue of the mechanical arrange-
am" with far greater ssMaiaty es to result'. The slightest
Mm NOW. lathe wheal math* Ina rail ceases the nastru-
mot to mew mod the central tower, while
a wheel at tho flea homfretthe observer, by a beautiful!
adaptation Minesbeeliel gimes, ambles him to elevate or
depress the ebisetidess with the greatest precision and
facility. So easy, In fast, Is the asmtzol over the instru-
ment in this respect, that a yeq ellikt touch cm the wheel
lifts 10 cwt. It may be , alm, that there cannot he
the slightest Henan In the tube; as error or deflection
arising from that came am Near, whilethe owe with which
it can be directed towage any point the heavens will
amble the observer to make profitable sac M any patch of
clear My, hewer traoshaat it may be. Ths grut value
of this owl oat be paloied out to those accustomed to
rookies aotemoosaisal observation. With respect to
the aosigedtlies power of this novel instrument, it
is only armassay is state that, though the focus
la set se print is it will be shortly, at has already
the whole in the mass way as Lord Bone's.
it elm aspraisoll same of the double stars in the Great
Bear, sad shows dielactly • clear disuses of 60 or 80 de-
yen betweee limy with several other stars occupying the
iaternaing apse. Ordinary readers will better underlined
the eitseerdiaery rasenifyang power of the telescope when
we Mhos them that by at • quarter-inch letter can be read
at the atone of half a mile.

The preparations for this really national work have bees
progressing for the last two years under the superintand.
epee of Mr. °matt u engineer and mathematician, but it
is only about three asontlu since the superstructure at
Wandsworth.ecommon was commenced, and it is ahead,
near completion. We understand that the Observatory
likely to he endowed be its liberal and enlightened creator.
Lord Rome has visited the Observatory, and espreucd his
admiration of this novel and interesting invention.

A mEw PLANET wu discovered by Mr. J. R. Hind
at Mr. Bishop's observatory, Regent's-park, at Ilh. 3Ont
mean time on :iunday night, the sixth he has detected
during the put five years. It is in the constellation
Aquarius, and will be readily seen with a telescope of very
ordinary power. In brightnew it equals a star of the ninth
magnitude, and appears to have the same yellowish tinge
that has been noticed about Pella*, Melpomene, and others
of the same group of plaits. At Ilh. 36m. 385., Green-
wich mean time (August 22), its right aseensies was
22h. 22.. 29.7.., and its north polar distance 97 deg.
32 min. 11 sec. the diurnal motion in right ucension
63 see. toward; the west, and in N.P.D. about 6 min.
towards the south.

MR. MACAULAY.—Many of our readers will regret
to learn that there is not only a chance, but a atrong pro-
bability, that Mr. Macaulay will not take his seat for Edin-
burgh. It is confidently reported that the mate of his health
is such that his medial attendants have advised him to re-
frain from making any public appearance whatever. Should
the story unfortunately prove true, there will, in all likeli-
hood, be another severe contest for Edinburgh, unless, in-
deed, wee man of trawboeudaut claims be brought forward
to unite the suffrages of the great bulk of the liberal party.
—Aberdeen Beratd.