The Potter journal and news item. [volume] (Coudersport, Pa.) 1872-1874, 1873-03-14

a a.
equipped with instruments for the
observation Of contacts, with hello
meters, and with Photographic APP
paratus. The photographs will be
made by the means of equatorial tele-
scopes, Of 59 inches aperture and
about 6 feet focus. driven by clock
work. OF the subsidiary parties one
will be sent to Mauritius, prov ided
with heliometers, and another to Per-
sia, for Photographic work solely.
. France provides for eight or nine
stations. In the north she sends to
the Red Sea, to Palestine, TO Pekin,
and to Ycddo, in Japan. In the south
to Reunion Island. st. Paul, Camp
bell Island. and New Caledonia, with
probably station at the Sandwich
Islands. The precise equipment of
the parties is not settled but they
will rely mainly on photography, and
will not use the heliometer to any
extent. The English Government
sends out five parties to occupy Oahu
(Sandwich Islands), kerguelen's
Island, Rodriguez Island. Auckland
(New Zealand), and Alexandria, in
Egypt. There will also be one or
two stations in Northern lndia-one
certainly at Peshswur. The astron-
omer royal relies mainly on the OBJ
servation Of contacts; but photo
graphy will also be provided for
The equipment of each party will
consist essentially of clock and
altazimuth instrument, with an equa-
torial Of six inches aperture. driven
by clockwork, and sO-called pbothc-
liograph. This is a small telescope,
driven by clockwork, and provided
with an enlarging lens, by which 4
picture of the sun some four inches
in diameter can be obtained. This
plan Of photographing is regarded
with suspicion by most non English
astronomers, on accOunt Of the dam
ger Of distortion in the enl urged i'm
age. IIeliometers will not be used.
Our own Government Is doing its
part molly. Eight parties will be
sent out-four to Japan and the
neighboring countrie5 and four to
the Southern Pacific. Probably also
a ninth, for the mere observation Of
contacts, will 60 to the Aleutian
Islands. Our parties, besides the
usual apparatus for TIE determine
ton Of time and geographical posi-
ton, will be equipped with 5-inch
! clock-dliven equatorials, and with
most perfect and elaborate photo
graphic apparatus, upon which the
main reliance will be placed. The
image will be made of sufficient size.
without any enlargement, by using
an ohject-glass of very long focus, in
the manner proposed and successfully
practised by Professor Winlock, of
Harvard College. The tube of the
F.. Photographic telescope, which is
some 80 or 40 feet long, is placed
horizontally, and the suns rays are
reflected through it by plane mir
ror, driven by cl0ckwork. An instru-
ment of this kind is. Of course, less
portable and easy to manage than the
photheliograph; but it is generally
believed that the results will be
enough more accurate to repay we'll
tie extra trouble and expense. The
parties are not yet organized as TO
their personnel; but the instruments
are in a good state'o forward ness, at
the workshop Of the Clarks. in Cam
bridgeport. 1t is expected that the
expense Of the expeditions will lie
between $150,000 and S250.000, Of
which S50,000 has already been ap-
propriated by Congress, for instru-
ments and preliminary arrangements,
and placed under the control of a
commission, consisting of the super
ntendent of the Coast Survey (Prof.
PIERCE, the president Of the National
Academy of Sciences prof Henry,
the superintendent of the Naval OBJ
servatory (Admiral Sands), and two
professors of the same institution
(Prof. Newcomb and Harkness). The
final selection Of stations and assign
meRt of observers will come in due
season. 1t is proposed that each
party consist of an astronomer in
charge, an assistant astronomer, two
or three Photographic assistants, and
a mechanician, with such laborers as
the nature of the station may de-
mand.
Besides these government expedi-
-ti0nS. several nriyata oneS will nrob