The News-Herald. [volume] (Hillsboro, Highland Co., Ohio) 1886-1973, 1891-04-30
THE LARGEST LENS.
A Telescope with 2 Forty'-Inoh
Glass for Mt. Wilson.
II WIN BE Constructed for the University
Of Southern California and win he
Located Near the City Of
Los Angeles.


Located Near the City Of
Los Angeles.
The ambition of the astronomer TO
probe deeper and deeper into the
fathomless depths of space and to bring
order Ito his sight, for his mind tells
him that order exists) out Of the ap-
parent confusion has kept the glass
makers and opticians busy, with the re-
suit that the fve-inch single lenses OF
Huyghens, that required a local length
of forty, fifty or one hundred feet, were
improved upon by the invention of the
achromatic lens by Dolland, upon
which subsequent Improvement has,
been made only in quality and power
and not in principle.
The four-inch lens of Dolland, in 1900,
developed into the nine-inch lens In
1880, and from 1S45 to 1861 the fifteen
inch telescopes at Harvard observa-
tory and at St. Petersburg were the
largest and most powerful instruments
in the world. From that period till to-
day the size and power have constantly
increased, first to eighteen inches, then
to twenty-three, twenty-six, thirty,
thirty-six, and now the Clarks, Of Cam
bridge, will soon be working upon one
forty inches In diameter.
At various stages of the progress Of
telescope making, says the New York
of useful power had been reached, but
after each increase it was found that
with proper selection of site the
density of the atmosphere did not inter
fere so much with the observers as was
anticipated.
About the forty-inch glass which is
for the university of Southern Cali
fornia and which arrived here q short
time since, Mr.. Clark says the managers
have not yet given him contract to
make the lens for it, but he expects it
| every day. He has the glass, and no
| other optician in the world can do the
work; so there is no doubt that he will
do it,
Mr.. Clark has offered to make the
telescope complete for 500, 900; that is,
o visual telescope, and he has further
| agreed to make it both visual and pho
tographic for $1Os,00O. An interesting
| incident is connected with the inn
portation of the glass. When Charles
| Sumner was ia the national senate he
introduced bill designed especially
to allow Alvan Clark, Sr., to import the
| glass for his lenses free, and the law
still remains. But recently the treasury
| department made decision whereby
disks for lenses are subjected to duty
Of 4s per cent.
This meant everything to the Clarks,
as they would have had to- pay thou
sands of dollars tax on glass they had
already ordered, the forty-inch glass be-
ing included. Mr.. Clark went to Wash
ington, and, backed by several distin-
guished scientists. endeavored to con-
vince the department that under the
law the glass should come In free, but
First Assistant Secretary Of tho Treas
| ury Tichenor, who made the decision,
refused to be convinced.
Mr.. Clark returned home with q thor
| ough determination tc Ia,.o ,.:a tools to
Europe and to do his work there. but
case and the decision was reversed.
Mr.. Clark says that he will in all prob
ability not begin on the lenses for a
year, and as it will take two years to
do the work on both of them-the flint
glass has not yet arrived-it will be
three years before the telescope is fin
ished.
When completed It will be mounted
in an observatory to be situated on
Wilson Peak, thirteen miles from Los
Angeles, Cal. Mr.. Clark and Prof.
| Pickeriup of Harvard think that this