Iowa County democrat. [volume] (Mineral Point, Wis.) 1877-1938, 1903-11-19
ONE AT CAMBRIDGE AND ONE IN
SOUTH AMERICA.
OF THE REFLECTING TYPE
Modern Astronomical Science Turns
Back a Century for a Model
Two Years of Hard Labor on
Single Mirror.-other Matters of
Interest.

cessful has been the preliminary work
/ with the new 24.inch Clark mirror
for the Harvard observatory, that a
second and similar telescope has been
ordered. One of these instruments
will be set up at Cambridge or at
| some other point near Boston, while
the other will go to the Harvard sta
ton at Arequipa, Peru, there to take
it's part in the systematic study and
Photographic record of the southern
firmament-a work which parallels
and completes the labors of the Cam
bridge observatory.
The new Arequipa telescope is in
j terc sting, moreover, because it is 60
ing to give a practical opportunity
to test side by side two telescopes of
opposite character For many years,
it may be recalled, there have been
controversies among astronomers re-
garding the respective merits of re-
fraeting and rejecting telescopes. A
rorracting telescope is similar to the
! layman's spyglass in construction
long tube with convex lens, at one
end and an eyepiece at the other
so that you look right through it di
rectIy at the stars. On the other
hand, a rejecting telescope, such as
Hafvard's mirror is made for, reverses
the order of things, SO to speak, for
the observer gets up at the elevated
end and looks down into a concaye
mi! ror across the face of which the
4 heavenly bodies swim in their mag
nihad form. The new Harvard tele-
scc3c will be OF the rejecting type,
having q mirror of carefully polished
/ glass backed with silver. When it is
finished it will be set at Arequipa side
by side with a refracting telescope of
tho same size and operated under the
same general conditions. In such
circumstances a comparison may
cas- ly be made which, it is believed,
will do more than merely satisfy
scientific curiosity, since it will re-
veal definitely the respective value of
these two important types of modern
telescopes in certain difficult fields
of astronomical research.
During the past 10 or 20 years
there has been, it is said, a decided
reaction among astronomers in
favor of the type of instrument just
;, ordered by the Harvard observatory
and honored, even by those who
J, supported the claims of it's refracting
!, rival, as the instrument used by the
Herschels in making some of the
1 greatest discoveries of modern as
tronomy. True it is that after Lord
the refracting type came into very
general use, since the instrument is
much easier to handle. There is an
objection, however, in that one has to
pay for this greater convenience by a
loss of much of the light transmitted
through the refracting lenses. Some
20 years ago Mr. Common, an English
astronomer, once more attracted at
tention to the rejecting telescope by
the admirable results which he OBJ
tanned. Later a still larger reflector
was made in England, but nothing
mu2N was done with it until It passed
into the hands of Professor Keller,
: VI lllS lIlCh oDStl NdtOly. WIZ uoSu II
while making additions to our knowl
edge Cf the patches of distant stars
known as nebulae This work was
continued after Professor Keeler's
death by his successor Professor
Campbell, and by Mr.. Richey Of the
Yerkes observatory at Lake Geneva.
Wis, who himself constructed large
reflector with which he included star
clusters and double stars as well as
nebulae within the fiele of his investi-
cations.
In the mooted discussion of the
value of the two types of instruments
the work of these astronomers re.
stored the rejecting telescope to a
position of great Importance. but
proved only, according to some as
trcnomers, that the success lay not in
the instrument itself but in the skill
Of the man who used It. One adyan-
tage it certainly does have, and a
most important one to the Harvard
observatory, which has done so much
in photcg, aphing stellar speetra--its
focus is unvarying for all colors, while
that of the resracting instrument diff
!ers considerably.
The rejecting telescope, in the
opinion of these opponents, is diff.
flcult piece of apparatus to work
with, even under the most favorable
circumstances, The new mirror at
Cambridge for example-and the mir.
ror. Ct course, is the first and all inn
20, tant consideration in any reflect.
ing teescope-must be mounted In
the most delicate manner. so that 1t
Is Guest on whether II will finally
be placed at the observatory in Cam
bridge or somewhere else In the neigh
horhood. Electric cars. which though
they help along civilization in gen.
eral, often prove a hindrance to
specific scientific work. pass close by
! the observatory and the tremors
started up rs they pass as well as