The interior journal. [volume] (Stanford, Ky.) 1872-1881, 1876-02-18
The Se~ Tssesespe IN she Fw~ss ~.
sevruforv.

TIE Se~ Tssesespe IN she g'w~ss ~
serruferv.
An immense rejecting telescope
equaling IN size the similar instrument
located at Melgournc, Australia, ha.
lately been constructed under the su
pervision Of Mr.. Lcverrier. at tho
observatory at Paris, France. The re
flector, which Is ~. s inches in diameter
Is mounted in tube %. 3 feet in length,
which Is composed Of n central cast
irua cylinder, to the extremities Of
which two smaller tubes, 90 feet long
each are secured. The end tubes are
formed Of four rings Of wrought iron
connected by ~ longitudinal bars Of
like material. The whole tube is GOV.
cred with thin sheets of steel, and
weighs $3.50 lbs. At the lower ex.
tremity is affixed the cast iron barrel
which holds the rejecting mirror; ut
the upper end circle. movable on the
open orifce Of the telescope, supports
q plane mirror which reflects sideways
the cone of rays previously reflected
by the large glass. and directs them
into the field of the eyc-glass.
1t will be seen from the above that
the telescope is constructed on the
Newtoninn system, and differs from
tie Melbourne instrument in that the
latter is built on.the Cassegrainian plan.
The weight Of the huge reflector ia it.
barrel is l,7G0 lbs, and the eyepicce,
with its accessories, aggregates the
same. The posing Of the mass is SO
perfect that even in the most unfavor-
able positions the mirrors are exactly
concentric,a and not the least DETECTION is
perceptible. For the accommodation
of the observer carriage running on
rails, is used, which supports
a lofty balcony. The latter is
sufficiently elevated to allow easy ac-
cess to the eyepicce, which can be ad-
justed at any point around the orifce
of the instrument.
The equatorial mounting turns on
an axis OF cast iron and steel, the di-
rection of which is parallel to the axis
of the celestial sphere. The telescope
can be inclined more or les, on this
axis by turning around second steel
axis. which traverses the first at right
angles, and partici pates in its move
ment of rotation. The two axes taken
together are marvel of mechanical aa.
curacy. With the telescope they weigh
%, 600 lbs. aud yet so perfect is the
machinery that the great tube follows
the movements of the heavenly bodies.
in obedience to the regulation of a
with as much certainty
and delicacy rs move the hands of the
timepiece itself.
The optical portion of the telescope
is as perfect as the adjusting mechan-
ism. Both mirror and eyepiece are
aud the former, it is slated,
reflects fully nine tenths Of the light re-
ceived. With an instrument. there
fore, uniting in itself so many highly
important advantages, il may be
hoped that valuable discoveries will be
made.
NJ. Wolf, the weil-known astrono-
mer, to whom has been confied il,
care, proposes to begin with the study
Of the planets aud their satellites, with
the view Of investigating many unsol-
ved questions relative to the rotation
of the worlds furthest removed from
our own; and at the same time, an
extended series of spectroscopic and
Photographic studies of the fixed stars
will be presented.-[Scienti6c Amer
lean.