Evening journal., 1899-08-04

the ever mobile satellites perpetually I
crafty the observers eye.
Luna, still moving eastward viii
come into conjunction with Uranus on
the 18th and with Saturn on the 10th.
The position Of the former planet has
changed but slightly since last month,
and it is just visible to the unaided
eye on a clear, moonless night, about
five degrees north and west of the
bright red star Antares, in the Scorpion.
The view of Saturn would be perfect
but for its low elevation. Telescope
definition is affected by the refraction
of the atmosphere near the horizon,
yet the Saturnian globe, with its mark
ings, the royal rings that surround it
and the play of its satellites, affords an
exquisite feast. 1t were well to avail
oneself Of every opportunity Of exam
ining this noble and unique object,
eloquent with hints of creative pro-
cesses
On the Cd the moon, in its last quar-
ter will sweep close by Neptune, which
is now a morning star, but always in
visible to the naked eye.
During the month, on starlit nights,
when the moon is in hiding, may be
frequently noticed the dash of me-
teor across the deep blue vault Doubt
less many photographs of these spec
trail fittings will be taken by special
students of such phenomena as prac-
tice for the work of the coming No
vember. Some 800 radiant points are
now known. Of which fifty are def
'lnitely located. Among the more promi-
! lnent displays of the year are those Of
the Perseids, so called because their ra-
diant point is in the constellation
Perseus; and, as their maximum oc-
= ours about the 10th of August, they are
! usually known as the August Meteors.
However. the duration of the shower
r covers some thirty-fve days, and en-
braces a part of July. The Perseids, so
? called because theirradiant is as swift as
the Leondis. which advance directly
7 toward us.
, The Astrophysical Journal for June
' contains an interesting contribution
D by S. A. Mitchell upon experiments IN
g stellar photography with the direct
y concave grating specuoscope. Even
with very small grating sixteen lines
e of the hydrogen series were obtained
e in a photograph Of the spectrom oi
q Sirius. and this-which is very signifi
e Notwithstanding the jar dust
s and glare experienced on the sixth
|, floor of the Physical Laboratory Of the
n Johns Hopkins University.
e The process is simple, the apparatus
" consisting merely of a grating on it
n holder with its side and back adjust
E. ments and a focuss accessory for tn
% plate holder. The whole is enclosed il
J. wooden box clamped to the tube
an equatorial telescope which serve
merely as a carrier. The ruled line
OF the grating are made parallel to tn
equator by the position of the box o.
IS the tube and the slight irregularitie
of the driving clock are thus negative
in the definition secured, the move
he ment in declination being guarded b
q the use of a filar micrometer. No sll
D. is employed, and, as neither objectiy
u nor prism is employed, there is n
IN absorption of the ultraviolet ligh
u and the Photographic spectrum e'
ne tends far into that region. Absolul
ne wave lengths-and as a sequence m'
th ton in the line Of sight-can be d.
" termined. Valuable results were ol
MS tained also in photographs Of II
Great Nebula in Orion.
ne BY the favor of Professor Snyde
en- the writer recently enjoyed a glimpI
TO of a part of the new equipment of q
sa Philadelphia Observatory in its ten
porary sheltering place. The spe
Is trometer and comparator evince ra
he workmanship, and the dark element
o. lines in the solar spectrum produc
by the concave grating are startling
IT. distinct. suggesting, as one rang
TN the exquisite color band, the appare
Ius movement of the upright rods in
ne iron fence, when one walks leisure
AD along its base.
The third Astronomical and Astr
the physical Conference will be held
ht- Yerkes Observatory September 6
MY when the organization Of a permane
not society will probably be effected.
Of 'o''
he -