Evening star. [volume] (Washington, D.C.) 1854-1972, 1893-08-26
Another Grent Tele.cope.

From the New York Tribune.
The opening exhibit of the forty-inch
ferkes telescope at Chicago this week is
an occurrence Of no little general interest
10 botn the lay and the scientific mind
sfnnenSnIySs ,,s. ,,a,,, iase'naung study. The
and the brilliant beauty OF fits phenomena
attract while they bewilder 1t offers,
moreover, a field OF inestimable richness
for research and for the enlargement OF
human knowledge. But this is a field whose
cultivation depends more than any other,
upon the implements used. Invention is
vain; speculation is futile: calculation waits
on data. Actual observation through power
ful instruments alone can give results and
promise further results. and so progress
in astronomical knowledge must be meas
ured by the progress made in the manu-
facture OF astronomical instruments. How
much further progress will be made or
can be made, in this direction, he would be
rash who should attempt to say. No such
limit vet appears as has been reached, for
requisite care and skill in casting and
grinding glasses, there seems TO be no
good reason why telescopes should not
be made by far exceeding in size and power
the greatest of those now projected
1t is one thing, however. to plan a huge
telescope. and even make its tube, and ex-
another and far different thing to make
the lenses and put the machine to use.
The Lick telescope is smaller than the
ferkes, Yet what a task IL was TO make
Its ponderous objective, Disc after disc of
crown glass was cast, at great expense
anu lapor, only 10 De rejected. Some got
broken, some contained flaws. some were
spoiled in cooling, some We're ruined I'm
annealing. After more than thirty attempts
success was attained. Then il was the task
of more than a vea- 10 grind and noiisb
the disc, and the care bestowed on the
packing and transportation of IL was such
as no cargo OF gold or diamonds ever re-
ceiyed. This was an objective thirty-six
inches In diameter. That of the Yerkes
telescope is forty inches, and proportion
ately more difficult to make.
When this great instrument is finished
IL will be. in size. without a rival and
increase in equal ratio with their size, it
ought to excel all others in power. Its
nearest competitor In size is the Lick tele-
scope, with its thirty-six inch disc. Russia
largest, In the Royal Observatory at Green
witch, measures twenty-eight inches, the
same as Dr. Diapers largest and that
at Yale. The great telescope at Washing
that at Princeton Of twenty-three. There
are other much larger tubes, but they are
refiectors. not refractors-an entirely diff
ferent type Mr. Commons. at Ealing. Eng
There is one of forty-eight inches at Mel
bourne. The famous Herschel reflector also
measures forty-eight inches, while Lord
Roses mighty tube boasts a speculum no
less than seventy-two inches in diameter
How the Yerkes forty-inch refractor will
compare with these may in part be reck-
oned from the fact that. after careful con-
sideradon, the builders OF the Lick tele-
scope preferred the thirtysix inch refractor
to a proposed seventy-two inch reflector.
A possible rival to the Ye-kes telescope
and the only one yet beard OF, is the great
build for the Paris exposition of 1900. and
which is to have a spectrum lis inches In
diameter and tube 132 feet long. But
ment on exhibition at Chicago will be
supreme.