Wood County reporter. [volume] (Grand Rapids [i.e. Wisconsin Rapids], Wis.) 1857-1923, 1885-08-20
A HUGE TELESCOPE.
Right Ascension and Declinatfon OF
Heavenly Bodies Explained.
Pittsburg Dispatch

Pittsburg Dispatch
Up on the side of the hill off Twen-
ty-fourth street, embowered in foliage
and giving no outward sign of the
business conducted within, are plant
ed the laboratory and workshops of
John A. Brashear.
There is now in his shop, in a fin
lshed state, a magnificent rejecting
telescope, made to the order of +. G.
Dupont, the celebrated powder manu-
| facturer OF Wilmington, Del, which
is to be mounted In his private observ-
atory, erected near his home in that
city.
The glass is made to fit the dome of
the observatory, in another part of
which he already has 3 similar glass.
The dome is In the spapc of a half~
sphere, through which is cut an aper~
ture from the base to the zenith to
allow the end of the glass to protrude
at any angle of elevation desired and
the whole dome and glass can be turn
ed TO any point of the compass at
Will The object of these motions is
to allow the glass to be brought to
bear on any given point of right as
cension or declination, which answers
IN astronomy for latitude and longi-
tude when applied to the earth.
To find Pittsburg on a chart
or map the observer looks first
for its latitude or distance north of
the equator, then for it's longitude Or
distance east or west from given
meridian, which in A merica is the
city Of Washington; then by follow
ing these two lines until they meet
Pittsburgh is found. So in finding
the position of a lar or planet in
the heavens it is necessary first to
learn its right ascension, or distance
IN degrees above the horizon, and its
declination, or position oR line from
the zenith to the horizon and where
these lines meet the star is found.
The great desideratum in very
large glasses is to construct them
that they can readily be handled and
easily pointed upon any spot IN the
heavens from perpendicular or any
position between that and horizon
tai.
This glass is of a rejecting make
and is seven feet four inches in focal
works from the object end. The focal
tube is empty and not unlike section
of stove-pipe, there being nothing to
ObstrUct the view of the rehscting
glass which is set in the bottom. The
tube is then turned in the direction of
the object to be inspected, and the
picture is reflected on a small trans~
verse mirror, which throws the pic~
ture out, through the side of the tube
near the mouth and into an observ-
er looking apparently into the tube
when observing body in the heav-
ems. This glass is fitted with clock
work attachment, which will move
the glass in the direct path of any ob-
jeCt on whice it has been set, allowing
the observer to leave the glass for
hoars at a time and on his return to
find the OBJECT at once.
An idea of the power of this glass
was obtained by pointing 1t on the
crest of the most distant hill on the
north side of the river, where the nail
heads in the weather boarding of a
building could be seen distintly, and
the features of q woman sewing in the
window could be recognized. Mr.. G..
w. Klages, the attendant, adjusted
powerful eye-glass to the tube, and a
letter-carrier who Just entered was
given a look. He said the men were
raking hay in the valley back of the
hills, as he imagined he could see it.
The illusion was SO great, from the
nearness Ct the hills, that he really
could smell new mown hay.
Prof. Rowland, of Harvard college,
has built and sold to the John Hops
kins university a ruling~engine, in
tended 30 marx standard measures
ments on tools, and for all other pur-
poses. In order to make this engine
perfect the professor was allowed ac~
cess to the French standard, Whit
worth's English standard and the
American standard, which is medi-
fcatien of the English. He has de-
dected standard from the combined
three which is perfect. Mr.. Brashear
polishes plates to receive these
measurements. The plates are cast
from combination of tin and copper,
and so brittlethat theycan be crumbled
in the fingers. This brittleness is a
great and valuable feature, as it al
lows of cutting very fine lines on its
polished surface, SO fine as to be
invisible to the unaided eye, being
Ia, 436 lines in each inch of space. A
fine diamond is used in cutting, and
the engine Is so truly adjusted and
dellcately constructed that it cuts these
lines with precision. The effect to the
eye on a polished surface is very like
the dampness from warm breath.
These standards are sold to manufac>
tureIs of ali kinds Of machinery, and
it IS now rare thing to find two
articles of the same stated size, made
by two manufacturers, that do not
assimilate ia size
Death Rid OF Its TerrOrs.
New York Sun.