Daily Yellowstone journal., 1888-11-20
A BIG TELESCOPE LENS.
The Great Lick Instrument Noe Larry
Enough-A Delicate Undertaking.

scope lens, received a letter from the
president of the University OF Southern
California, located at Los Angeles, ask
ing for information as to a forty inch
lens, and intimsting that Al order for 8
telescope to eclipse that at the Lick OBJ
servatory would soon be sent.
A correspondent who was present
turned his attention to the numerous
lenses Of different sizes and in various
stages Of manufacture while Mr.. CLARK
was reading the letter. He had just
been talking with the man who had made
eyes that could read patent medicine
signs on the moons rocks with regard to
the possibility for further advance in as
Economical researches, and he feared the
letter might make il necessary to shorten
his visit, Mr.. Clark's eyes twinkled a.
he read the letter. Then, without .
word OF comment. he handed the missivs
TO the reporter and resumed tn, patient
rub. rub, rub Of q small lens glass on the
polishing block.
"What do You think Of thatf' hs
asked, when the reporter had made .
careful mental note Of the contents Of The
letter.
II thought II had been stated by some
savants hat il was impossible TO finish .
lens any larger in diameter than that
sent to the Lick observatory" the repor.
ter said.
Il know such . statement has been
made" replied Mr.. Clark. but ! do not
indOrse ii. I've been making telescops
lenses now for . good many years, and !
ought to know something about il. III
can get the glass the proper size there
will be no trouble in making a lens forty
inches in diameter. I'd make a five
footerif my life WAS spared long enough"
do you mean to say that there Is q
possibility in the future of having tele-
scopes five feet in diameteri"
IL don't see why they should not be as
large as that. But mind you, it would
take about one mans lifetime to make
such a lens. In the first place, it would
he necessary to get a piece Of glass alb
solutely perfect in every way. The
slightest flaw or variation in density
would spoil it for a big lens. It might
be a generation before such a piece Of
glass could be manufactured. Then it
must be ground and polished by hand.
But ! believe such a lens can he made,
| and | believe i will be made"
"Will it he of any practical advantage
to astronomers
Certainly ii viii. Its increased mag
nifying power viii he in proportion 10 It's
increased sized. Take this forty-imch
lens that has been mentioned as AN cy-
ample. lis size would he oGc-ninth
larger than the Lick observatory lens.
and it would make given objects appear
nine times larger or nine times nearer.
Increase the diameter of the lens and YOU
will increase the power to examine
worlds that have not yet been seen. II
a lenSfive feet in diameter is secured, it
will bring the noon So close that we can
see every nook and Granny on its surface.
As for new stars, there is no limit to the
discoveries that could lie made. Ii would
revolutionize astronomical researches
Had YOU thought of making a larger
lens than that in the Lick telescope before
you received this letter.
'0h. yes. / am not surprised at re-
ceivlng this letter. for when | was in
California a year ago the president of that
university intimated that they should
want a larger telescope than that on
Mount Hamilton. There is a wonderful
amount Of interest in astronomy in Cali
fornia. All sorts of people are studying
the science. This five inch lens | am
polishing is for a telescope l am making
for the president of that university. 1t is
for his personal use, aud he begged me
to make it with my own hands, so ! I'M
pegging away at it when | get the time.
| have also filed other small orders from
that state. In addition TO those small orders
| have received no less than three letters
from different colleges asking if l could
make a forty inch lens. lhave written all
those persons that ! was ready TO accept
any and all orders for q forty inch lens.
In fact, | was 80 sure that there would DO
a demand for such a lens that I gave an
order To the glass men in Paris to save
for me the first large mold that they sue
ceeded in getting out. may get it in a
few weeks and I may have e wait
months and weeks for it. heard the
other day that they had cut out two
extra large plates and were finishing
them for the exhibition next veal. II
it's true, ! shall secure them IL money
will do it,
"What causes this delayl"
1T is all in the casting, y was the reply.
"All these lenses are made in France,
near Paris. They are making them all
the time. They melt upa lot Of glass,
and when it is Of the right consistency
they set it aside TO cool. The glass il
melted in huge pots, and after every
casting the pots are broken away, leaving
a large mass Of glass, Then they examine
II and test il TO see II il is suitable To spill
up into lenses. 1t must be just right OF
ii must be melted over. They have order,
for all sizes Of lens, but they do not con.
slider those orders until they get the block
Of glass. The least indication Of strie OF
sediment will show that IL cannot be used
for larger lenses. Then they break il W
TO see IL they can use Il for small ones
There are generally enough imperfectioni
10 ruin the block for large lenses. II nonC
Ia visible 10 the eye the block is tested
with the p~olariscope, 20 see II IL Is ofever
density throughout. II all the conditions
are perfect, then they will split up tn,
block anc get out a large lens in tho
rough. II they succeed in doing that
there is still great danger that IL will In