The semi-weekly messenger., 1906-06-19
Uhe Messenger.
CLOSER STUDY OF THE HEAVENS.

Professor E. G.. Pickering, director of
the Harvard astronomical observatory,
makes a novel proposition for the ben
eft Of his professional brethren in this
and other countries. He suggests the
construction Of telescope whose di-
ameter shall be seven feet, or more
than twice as great as that Of the Lick
telescope. Partly for the sake Of
economy and partly because Of the
particular class Of service to which the
instrument would be almost exclusive
ly devoted, he would have a reflector,
not a refractor. Since there are fewer
observatOries in the southern heInis-
phere than in the northern, he prefers
a site on the other side Of the equator.
The usefulness of a telescope being
prOpOrtiOnate to the absence of cloudi-
ness in the locality where it is en-
pIoyed, Professor Pickering thinks that
the vicinity of Bloemfontein, South
Africa, would supply almost ideal con-
d1tons. There are said to be more
clear nights in year there on an av-
erage than at any other place in the
southern hemisphere which would in
ether respects be desirable. The new
observatory would engage in system
attic photography of the heavens,
copies of any of it's plates being fur
nished 10 astronomers elsewhere who
might need them in the prosecution of
their own inquiries.
For certain classes of astronomical
study it is desirable to supplement OBJ
servations III the northern hemisphere
with work in the southern. The spec
trum of star, for instance, is sup
posed to furnish a key to it's tempera-,
ture, its principal chemical cOnstitu-
ents and its motion away from or to-
ward the observer. If an Investigator
seeks to classify stars according to
their spectra for any reason, then he
naturally wants returns from the en-
tire sky, and not alone from the por-
ton visible at his own particular post.
Hence several northern institutions
have established temporary or perma-
nent anneXes south Of the equator in
the interests Of thOrOughneSs of re-
search. If one observatory could be
made to serve a dozen or score of
others in this manner, an increase of
knowledge might be secured at COM
paratiVely low cost. After it was once
built, equipped and endorsed, it could
afford to sell duplicates of it's pictures
at a merely nominal price.-New York
Tribune.
If Professor Pickering succeeds in
equipping his proposed observatory
with a seven-foot telescope he will be
acknowledged as having performed
great and wonderful feat. Such an in
strument would have two and a third
times the diameter of the Lick tele-
scope, the latter's diameter being only
thirty-six inches. There are two 9TH
ers larger than that one-that of the
Chicago University, given to it by
G. T. Yerkes, which has a diameter
of forty inches, and one built for the
Paris exposition, with diameter of fifty
inches. These were considered mon
sters at the time of their constructions
but now comes Professor Pickering
with a proposition to construct one
with the enormous diameter of eighty
four inches.
The telescope came into use in the
early part of the seventeenth century,
but, because of the inability to secure
suitable glass, for many years after the
invention it was impossible to make
lenses of more than five inches in di-
ameter. This was remedied in the be-
ginning of the nineteenth century, and |
since that time there has been steady |
enlargement of the lenses, but only in |
the latter half Of that century were any
made to exceed two feet.
If a seven foot lens can be made
why not one of eight, ten Or twelve
feet, or Of any size desired?
If this progress in telescope con-
struction continues there is no telling
how soon our astronomers will be able !
to see people on the moon and, per-
haps, on some of the planets and even
be able to become familiar with their
habits and occupations.