The late Earl of Rosse, with a devotion to science which has few
parallels, constructed this gigantic telescope, at his seat,
Parsonstown, in the south of Ireland. To the frame of the vast
instrument is fixed a large cubical wooden box, about eight feet wide;
in this there is a door, through which two men go in to remove, or to
replace, the cover of the mirror. To this box is fastened the tube,
which is made of deal staves, and hooped like a huge cask. It is about
40 feet long, and 8 feet diameter in the middle. _The Dean of Ely once
walked through the tube with an umbrella up!_ The stupendous speculum
weighs three tons; the casting and polishing of it were labours of
wonderful skill. The telescope is not turned to any part of the sky, but
limited to the range of half an hour on each side of the meridian,
through which its motion is given by powerful clockwork, independent of
the observer. For this purpose it stands between two pieces of masonry,
of gothic design, which harmonize with Lord Rosse's castle; one of these
piers sustaining the galleries for the observer, and the second the
clockwork and other apparatus. There is an elegant arrangement of
counterpoises to balance the enormous mass, so that a comparatively
slight force only is required to elevate or depress it. A correspondent
of the _Mechanics' Magazine_ thus describes the capacity of this
wonderful instrument:--
"Such is its power, that if a star of the first magnitude were removed
to such a distance, that its light would be three millions of years in
reaching us, this telescope would, nevertheless, show it to the human
eye. Is it to be wondered at, then, that, with such an instrument, grand
discoveries should be made? It has been pointed to the heavens; and,
although in the beginning of its career, it has already accomplished
mighty things. There are nebulous spots in the heavens which have
baffled all the instruments hitherto constructed, but this telescope
resolves their true character completely. Among the wonderful objects
which have been subject to its scrutiny, is the nebula in the
constellation of Orion. I have had an opportunity of examining it. It is
one of the most curious objects in the whole heavens. It is not round,
and it throws off furious lights. From the time of Herschel it has been
subjected to the examination of the most powerful instruments--but it
grew more and more mysterious and diverse in its character. When Lord
Rosse's great telescope was directed to its examination, it for a long
time resisted its power. He found it required patient examination--night
after night, and month after month. At length, a pure atmosphere gave
him the resolution of its constitution; and the stars of which it is
composed burst upon the sight of man for the first time!"
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