Phenix gazette. [volume] (Alexandria [D.C.]) 1825-1833, 1828-04-17

this solitaryvi!lage that the world was instruct
I'd in Whatever was most singular, and per-
hans, most diff ult 20 perceive in the heavens
1 he history of optical inventions, and Of their
progressive improvement, II is too well known
10 require any notice in this place. iierschers
te,escones are those that have bren named New
tonian But he never ceased TO study their pr o.
pre,ies. TO vary them aud extend their Is".-
Taught by long experience, he suppre ssed the
plain mirror which produced second rctlec-
ZION: and this happy change, when was long
before proposed by Lrmaire, but difficult OF ex-
ecu:ion, AMI only applicable in large instru>
ments, doubled, in mannor, the oP'loa' ffect
He found, that, by exercising the eye ~ a
gradual manner, il is rendered much more
sensible to the impression 81 weak light ana
Nv this means h. was'rnabisd 10 magnify the
images of objects much beyond the limits al
which otter observer had been arrested. He
detected two different properties which had
not vet been dis ingu,shed, that which con-
sis,s in augmentng the apparent dimensions
of bodies, and that Of prnet' aing i"to the pro
fundiy OF space 10 discover objects when
might have be. entirely i'npercep'ible. MIL
tiplird examples leave no doubt regarding the
truth and striking utility Of this distinction.
A, lerg,h he formed the r. solution tlcarry>
ing the power If these instruments to the high.
est possible limits; regarding less the circum~
stances calculated 10 facilitate their employ
nen,, than those which might augment their
optical power, he constructed telescope OF
Extraordinary dimensions 1t is indeed the
laryes, instrumsn, Of this kind that has ever
been made.
Let any one imagine to himself an iron tube
40 feet long and Is inches in diameter, sus-
pended beneath an assembIase Of inclined
masts; and moved in all directions by number
of machines. The entire system Is movable
round a vertical axis. and describes a circum-
ference Of 40 {, ct diameter. a highly polish
ed metallic mirror, weighing about 5000
pou nds, is introduced into the tube, and when
the instrument is turned towards lhe heavens
this mirror reflects ;he shining image Of the
stars. The observer is himself transported
along with the tube in any direction required,
for he is placed in seat attached TO the upper
extremity, the objects which he observes are
behind him, and he views their reflected ina
ges.
Her.chel discovered, with his telescope, two
new satellites of Saturn; they are both nearer
the planet than thns. made kr own by Huvgens
and Cassini Never had the heavens been OBJ
served with so extraordinary an instrument;
and it may he said, that the greatest phcnome-
na DISPLAYED themselves untlerIa novel aspect.
The he6olositics, those small luminous ard
irregular clouds which may be remarked
among the fixed stars, in various regions Of
the heavens, appeared almost all to resolve
themselves into an IHnumeraaole multitude Of
stars. Others, hitherto Imperceptible, seem TO
have acquired a dlstinci light. On the en-
trance of Sirius into the field Of the telescope,
the eye was so ,ioItn,ly> Affected. that stars
of les, magnitude could no, Immediately after
be perceived; and i, as necessary to wait for
twenty minutes before the Sc stars could be OBJ.
served