The Canton mail. [volume] (Canton, Miss.) 18??-1882, 1875-03-20
Giant Star-GaZers.
Two American Telescopes, the Largest
fn the World.

Two American Telescopes, the Largest
fn the World.
When Galileo's first telescope was
made, which enlarged an object less
than 5 diameters, it astonished the
world. And when he finally succeeded
in making one that magnified 80 diam
eters, it was said that the highest mag
nifying power had been reached, and
plausible reasons were given to sub
stantiate the statement. When, some
what later, Frauenhefer made the cele-
brated Dorpat telescope of Russia,
with an object glass of 81 inches in
aperture. its enormous power was the
cause of great excitement among as
ironomers throughout the world. The
famous Chicago telescope, with its 49,
inch aperture. made by CLARK & Sons,
at a cost of $4,000, has till lately been
at the head of great instruments of this
class. At Gateshead, near Newcastle,
England, Mr.. r. s. Newalls telescope,
made by Cooke & Sons, of York, with
25-inch aperture, has for several years
stood as the largest in the world,
though of inferior quality and power
At present the instrument in the naval
observatory at Washington, and now
in active operation there, gives to the
United States the distinction of having
the largest and most effective refracting
telescope that was ever constructed.
This, too, was made by Messrs. Clark,
who have now nearly completed another
of similar calibre, ordered by L. J.
Mccormick, of Chicago, of McCor-
mick's reaper fame. This, it is under
stood, will be given to one of the Vir-
ginia universities.
These twin monsters of the deep
sky, not sea-will, in every important
particular, be the counterpart of each
other. The only noticeable differences
are: The Washington instrument has
an aperture of 26 inches, while the Nc
Cormick has one of a little over 26, but
only enough to have it said that it is
the largest in the world the compound
objective or object glass in the latter
weighs ITO pounds, while that of the
former weighs $50 pounds. In each,
the glass, with the tube in which it is
inserted, weighs about a ton, and the
whole weight may be roughly estimated
at four or five tons. Each has focal
length of about SO feet. The cost of
the government telescope was SAG, 900
in currency. That of the Mccormick
will be $4,000 in gold. The con-
tract was made for both at the same
time, about four years ago, and at the
same price, gold being estimated as it
then stood. Mr.. Mccormick chose to
pay the amount in gold when his in
strument should be completed. The
detectives alone, when completed, are
worth S25, 900 each, and are capable of
a magnifying power of 1000 diameters,
though, owing to the interference of
the atmosphere, power of $500 will
seldom be used, but even this will in
crease the surface of the object viewed
to 2, $50, 900 times its natural size.
The establishment that gives birth to
these monster telescopes is situated in
Cambridgeport, Mass, within easy
rifle range from Boston state house. 1t
is an unpretending structure of plain
brick, two stories high, about 20 feet
long by 25 feet wide, with an L OF the
same width and 20 feet long, and
small one story room, perhaps Is by 20
feet. All the power used in this factory
is five-horse power engine, of which
more than three-horse power is seldom
needed. The firm is composed of Mr.,
Alvan Clark and his two sons. They
employ about a half-dozen hands, and
never have, in the busiest times, more
than ten. The senior Mr.. Clark is now
over 70 years of age, and did not begin
telescope making till he was over 40
yeals old. He has acquired his knowl-
edge and skill without instruction. He
has never seen lens in process of con-
struction in the hands of any one out
of his own shop. Yet here are made
instruments which no other maker in
the world has surpassed or equaled.