The great West. [volume] (St. Paul, Minn.) 1889-18??, 1890-11-14
sURvEYNGTHE HEAVENS
LARGEST TELESCOPE LENS IN
THE WORLD.
1 Look at the Glass that vim Bring the Inhsbi-
tants Of Mars Almost Within Hailing Dis.
tance-A Wonderful Piece Of
0lass-Its Value.

tance-A Wonderful Piece Of
Glass-Its Value.
In quiet little room at Cambridge
port not long since, was shown for the
first time the precious glass which is
to be used in making a telescope that
shall eclipse even the famous one now
mounted at tho Lick observatory in
California
When the lid of the big box was re-
moved Mr.. Clark tenderly lifted away
tho excelsior fiber which covered the
precious lens. There it lay. cushioned
on its soft bed and rejecting back the
light from the little oil lamp held at a
respectful distance by a careful assist
ant 1t was a sight for astronomical
eyes to behold. The glass measured
about 10 feet in circumference or feet
1 inches in diameter. Although it is
q inches thick at the center and II
inches at the edge. 1t was as transpar-
emit as a bit Of thin plate glass when
carefully it was raised on its edge in
the box. Mr.. Clark's hands {ondled it
as he would a baby while be murmured:
What a beauty it is; no one ever saw
its like"
George Clark fecked of the parti-
cles of dust that chung to it with soft
silk handkerchief and touched it as
lightly as lady might her powdered
cheek. Mr.. Widney's eyes danced
with pleasure as he glanced through
its transparent thickness. The Herald
reporter touched it reverently before
it was laid carefully back in its case
to await its finishing process. A sigh
OF relief escaped the veteran lens
maker when he saw it safely reposing
once more on its soft cushion and the
fibre replaced. He was in state Of
more or less anxiety till this was done,
for the lens represents about twelve
months work already. though two or
three years will be required to finish
it. When it is ready for its position
in the big telescope it will represent
value OF from 5000 to $4,000. It
is now insured for large sums by two
OF the biggest insurance companies in
Boston.
The first process that this new and,
so far, greatest lens ever attempted
will have to undergo will be that Of
grinding to the proper curve. It will
be placed on a mill and made to re-
volve at slow and uniform rate of
speed. The finest of sharp steel in
struments will cut out the surplus
glass, and a smoothing machine,
moving in a cons family changing
curve, will be for months and months
passing over its surface before the
lens can be utilized. During this time
It will be tested, perhaps hundreds Of
times. by the aid of silver mirror,
till its proper focal power shall have
been established.
Each OF the processes employed in
the operation is intricate and delicate.
That Of getting the correct focal power
may. however, be considered the most
interesting. On being set before the
mirror little starlike ray of light will
be made to pass through the lens and
reflected back through it again from
the mirror. Until all the inequalities
of density in the glass are removed,
the ray OF light transmitted will not
be perfect in shape. Back and forth
the lens will have to 60 from the grind
Ing and smoothing machine to the test
ing apparatus, until the tiny ray of
light is as perfect as when it leaves
the little lamp that sends it forth.
The largest astronomical photograph
lens previously made has been but
twenty-four inches in diameter, and it
is expected that the present one will
accomplish unheard-of triumphs in re-
vealing wonders of the starry firlna-
ment. Judge Widney said that through
1t the moon will look as if only 100
miles away. and that if there are any
cities or large buildings on its surface
their presence will be revealed through
Its aid. The glass, it is thought, will
also settle the question as to the sup
posed signals of light which the in
habitants of mars are understood to be
making to the people OF the earth.
The observatory for which this new
telescope is intended is to be about
twelve or fifteen miles from Los An
geles on part of the Sierra Madra
mountains, known as Wilson peak. It
Is claimed to be better sight for OBJ
servation than the Lick observatory.
1t is about 5000 feet above the sea
level, and is free from the mist and
fogs which roll in through the Golden
Gate and spoil many chances of OBJ
servation with the Lick telescope