Vilas County news. [volume] (Eagle River, Vilas County, Wis.) 1896-1927, 1903-11-23

the electric lights of a large city, may
make il advisable to place the new in
strument a little further from Boston
and from the possibility of such dis
I turbances. At Arequipa, when the
mirror Just ordered has been com
pleted, the trolley car problem is
naturally not likely TO come up.
It will probably be between two and
three years before the mirror Of the
1 ArequiDa telescope is ready 10 start
on its southern journey, for the manu-
| facture of one of these important
disks of glass is a long, tedious and
infinitely careful process. Making
/ perfect telescope mirror or lens, in
/ fact, is a hardly less remarkable
achievement than making a perfect
diamond; the main difference one
might almost say. is that the mirror
. has been made by man and that the
. diamond has not And so delicate Is
/ the operation that the famous lens
maker Clark found only one young
man whom he thought worthy TO be
| apprenticed TO his peculiar and. from
the astronomical point of view,
vitality important occupation. Mr.. c.
a. R. Lundin who made-Or figured"
! if one wishes 10 be more technical
the new Harvard mirror is there
fore a unique figure among modern
wOrlmen. It was he also. although
the last survivor OF the Clark family
lived until 1897, who did most of the
work on the famous 40-inch lens
which has given the Yerkes observa-
tory its present distinction of having
the worlds largest piece of astronom-
ical apparatus.
The finishing of such a mirror as
that just ordered by Harvard for her
Arequipa observatory, after il has
gone through its earlier processes, is
a matter OF about two years OF hand
labor, the maker having simply his
thumb, a dish of water and a bit of
fine powder with which slowly and
carefully to grind down the glass to
its final proportions And this work.
which appears in the first statement
exceedingly simple, is complicated by
a thousand and one difficulties known
only to those familiar with this finest
product of the telescOpe-maker's art.
Although the glass is manufactured
with cOnsummate care in the one fur
mace in the world that is capable Of
producing it, that furnace being as far
away from the lens-maker as the
Louvre is from Harvard university,
nevertheless this glass contains i'm
PROJECTIONS which must be carefully
investigated before the lens-maker
can be sure CT his material. A mir
ror may be easily injured in the finish
ing, for even the heat of mans
thumb causes an expansion of the
glass under it that, infinitesimal as it
is under any human system OF mea-
surement, may mar the perfection OF
an otherwise fawless mirror.
Until given the contract for the
new Harvard mirror the Clark man
agement had been almost invariably
making lenses of the refracting type
of telescope, the two types presenting
very different problems in glass
grinding. The new mirror, therefore.
proved to be something of an innova-
ton, one in which the astronomical
scienc of the twentieth century
reaches back to the early nineteenth.
and combines the favorite instrument
OF the great astronomer Herschel
with the skill of the famous maker
of the modern worlds best known as
Economical apparatus.