Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1892-12-02
AIDS TO ASTRONOMY.
Observations of the Past Year at
Cambridge and in Peru
MAKE GREAT STRIDES FORWARD
some of the discoveries Of Vast Interest to
ALI scientists.
EXCELLENT PHOTOGRAPHS BEING MADE
ESPECIAL TELEGRAM TO THE DISPATCH.


BOSTON, Dec. 1.-Prof Pickering says
in his annual report, just issued. that the
Harvard observatory astronomers made
great many interesting astronomical dis
coveries last year, both in Cambridge and
in Peru. There were taken 2,777 stellar
photographs in Cambridge and nearly 1000
in Peru. The examination of these plates
has. as usual, led to the discovery OF alarge
number of interesting objects. Ten variable
stars q. Delphinis, s. Pegasi, T. Aquarii,
r. Crateris, R. Carine, S. CAMS MINORS.
s. Carine, R. Ophiuchi. Ophiuchi and
Espius, variable star in Auriga, in ad-
dition to those previously announced, have
the hydrogen lines bright in their spectra.
Seven new variable stars have been discov-
cred this year by means of this property.
The number of stars of the fifth type has
been increased by eight, making the total
number now known of the objects As The
hydrogen line was shown to be bright in the
spectra of six stars in addition to those al
ready known. Photographs have been OBJ
tanned of the spectra of eight planetary
pebulR, showing bright lines. The spec
trum OF the nebuls surrounding some of
nebula. Five stars have been shown to
have spectra of the fourth type.
Valuable Material Rapidly Accommodating.
The amount of valuable material accumu-
lated with these instruments Is continually
increasing, and has proved useful in many
cases in studying the past history of new
objects The brightness for several years
past of stars suspected of variability has
a.
Plates have been sent to the Lick and Am
herst obseryatories and to the Smithsonian
Institution for special Investigations.
From one of them new variable star in
Aries was discovered by Prof Schaeberie.
It is hoped that this use of the plates may
increase in the future.
A large number of photographs were
taken of the new star in Auriga An ex-
animation Of the older photographs showed
that that the region containing it had been
photographed IS times from November 3,
1885. to November 2, 1891. and that it was
then apparently fainter than the IL nagni-
tude. Five plates showed it between De-
cember 16, 1891, and January 81, 1892. At
ter its discovery 1t was photographed on 65
chart plates and So spectrum plates until
April 6, when it became too ia mt to be visi-
BILE in the encroaching twilight All of
these plates have been carefully studied
and measured. Twenty-one charts and 15
spectrum plates of this object have been
taken since It's temperance in September,
shown to resemble that of a planetary
nebula
Some of the Photographs Taken.
Many photographs of the lunar eclipse
of November Is. 1891, were taken, both at
Cambridge and at the Boyden Observatory
in Arequipa, Peru. The examination of
these photographs for the detection of
possible lunar satellite led only to a mega
tive result
The observations taken in Peru have
been very valuable. Many interesting re-
suits have been derived from the observa-
tions made of the moon and various planets
The markings of Mercury have been
studied and this investigation appears to
confirm Schiaparelli's view that the rota-
tion OF Mercury on its axis occupies
the same time as its revolution in its orbit
An extensive series of observations was
also made upon Mars, and the relative
position of 90 points upon its surface were
determined by the micro meter. More than
40 minute black points were discovered,
Professionally designated as lakes. The
Polar compression of the planet was also
measured, and appeared to be greater than
that indicated BY theory, which may be due
to an excess of clouds in the equatorial re-
gions The presence of the dark and narrow
streaks called canals by Schiaparelli has
been confirmed, and various measurements
of them have been made The clouds pro-
jecting beyond the limb and terminal
have been studied, and their height has
been found to be at least 20 miles. Two
large dark blue areas have been detected on
the planet, and other portions have been
noticed to be subject to gradual changes.
Many new double stars were also found
south of 80, between II H and 18 H.
The New stations Established.
The august occultation of Jupiter was OBJ
served, both visually aud photographically,
also the new star in Auriga and Swift's
comet. Stations have been established at
Mallendo, 100 feet above the sea level, at
Lajoyce, whose elevation is 4, 150 feet; at the
observing station $3.50 feet high, at Cha
ehani Ravine, 16, $50 feet high.
The approaching completion of the new
Bruce Photographic telescope is referred to
at length by Prof Pickering. If successful
it will be the most powerful in the world.
The eight surfaces of its objective have
been ground and polished SO that it could
be tested on a star. The results were satis-
factory. The focal length proved that to be
desired, within nall OF per cent Plans
have been made and the foundations laid
for q one-story brick building with sliding
root, in which it will be erected during its
trial In Cambridge. After this it is pro-
posed to send It to the Arequips station in
Peru.
The value of photographs obtained with
the transit photometer was illustrated when
the new star in Aurora was discovered, in
February, 1892. 1t then appeared that this
object had been photographed on IL nights
since December 10, 1891, while no trace of
it was visible on Is plates covering this
region and taken before December 2, 1891.
The only knowledge that exists Of its
changes of light during the six weeks in
which 1t remained undiscovered is furnished
by these photographs and those taken with
the eight-inch telescopes.