Delaware gazette and state journal. (Wilmington, Del.) 1883-1902, 1884-07-03
URANyLUaR ron JULY.

ing sky, leaving to the Moon and the fixed
stars the duty Of identifying the nights OF
July. We look up now TO different stars
from those which shone for us in midwinter
but they possess no less interest for the
astronomer. The blazing Sirius has gone
ia lost in the light Of the Sun-but the t'dog
days" remind us of his continued existence.
The ''dog star" and hydrophobic dogs form
strange links in chain Of ideas, easily ex-
planned however on the hypothesis that the
heat of midsummer when the SUMS path lies
nearest to Sirius, is provocative of rabies.
Vega is now the brightest of the visible
fixed stars and will be found nearly overhead
at II O'Clock in the evening. This is one of
the stars whose distance from the Earth has
been the subject Of long continued and
elaborate calculations conducted by the
Washington astronomers within the past two
or three years. Its parallax ia about one
quarter of second, point as difficult to
measure as the diameter OF quarter OF
dollar dozen miles away. The computed
distances of fixed stars are generally stated
in the number OF years it would require for
light from them to reach the Earth, supposing
light to travel through space at the same rate
OF speed that it passes through our solar
system, about $4,000 miles per second. At
this rate il would take light from Vega some
l6 years to reach the Earth. So far as We are
aware, however, there is nothing known
about the speed Of light outside OF our own
system, and it may be possible that it flashes
simultaneously or nearly so over tho billions
OF miles which separate one solar system
from another. II we are forced TO measure
with our own solar system yardstick the vast
distances which intervene between our Sun
and the millions of other suns which the tele-
scope reveals, We are driven to the conclusion
that, in looking at some Of the remotest stars
which powerful instruments render visible,
we are beholding them not as they appear
now but as they appeared centuries ago and
that they may be blotted from the sky hum
dreds of years before they cease to shine for
US conclusion which appears improbable
IL not incredible.
The phases OF the July Moon are Full
Moon, Sth, $40 a. M; last quarter, 18th, ASS
p. M; new Moon, 22d, 7.53 a. M; first quar-
ter, 29th, sol p. m. There will be no occul-
tations Of fixed stars worth looking at during
the month. The Moon will be in conjunction
with Neptune on the 18th Saturn on the
18th Venus on the 2lst Jupiter and Mer-
curry on the Esd, and Uranus and Mars on the
10Th. None of these approaches, excepting
the conjunction with Venus, is close enough
to possess much interest, and they are all of
doubtful visibility.
Mercury is at present morning star, but
will pass the Sun on the 18th and become an
evening star. He will not be visible during
July five could view his seeming track
through the stars during the month, we
should find him entering the western side Of
the constellation Gemini, passing across that
constellation, very nearly in the track OF the
Sun, then across Cancer, passing on the 10th
between the two stars known az the ASSET,
and closing the month quite near Regulus,
the brightest star in tho Lion. Mercury will
reach his greatest western elongation late in
August setting then nearly two hours behind
the Sun.
gfYenus has practically left the evening sky.
She reaches inferior conjunction with the
Sun at D O'Clock on the evening OF the 18th,
being then almost directly between the Earth
and the Sun and having her dark side turned
toward us, like the Moon when new. At her
last inferior conjunction, on December 9Th
1889, Venus passed directly between the Earth
and Sun, and was seen like a black ball
transiting his disc Those who witnessed that
transit will not live to zee another the next
occurring in the year 20O4.
On the 18th of July Venus will seem to
have completed one revolution, as viewed
from the Earth, since her transit. In reality
she has been twice around the Sun and is
pretty well advanced on her third revolution
since then the length of her year being 1924
days.
On the day after passing the Sun, going
westward, Venus crosses the track of Mer-
curry, coming eastward, and the two planets
will DO in conjunction at a m OF tho 18th.
There will be this difference however Venus
is on this side and Mercury on the opposite
side Of the Sun. The path of Venus during
the month il from the eastern side of Gemini
westward about half way across the southern
part OF that constellation. On the I'd OF
August she reaches the end OF her westward
journey and proceeds to retrace her course to
the eastward.
Mars will be visible as an evening planet
throughout July, but is moving rapidly from
M and diminishing in brilliancy. The
diameter of his disc is now about 81 seconds;
ii was 10 seconds in January. During juno
he passed across the greater part Of Leo and
is now rapidly nearing thep place in the heavens
occupied by the distant planet Uranus. On
the 11th of July Mars will be within
seconds of the spot occupied by Uranus
year before. The great difference in the
speed with which the two planets move
through the consultations will be appreciated
when it il stated that in eight days there
after, on the 10Th, Mars will be in conjunction
with Uranus; having apparently moved as far
In that short time IN Uranus has gone in
whole year. Mars reyolVes around the Sun in
22 months Uranus in 81 years. The two
planets are only II seconds apart ut conjunc-
ton, which takes place however in the day.
time and could hardly be observed oven
through the best telescopes. A telescope of
moderate power though, will show them
after sunset while they arc still quite close
to each other. Continuing his journey Mars
will pass on the night OF August I'd within
seconds OF the star Eta Virgins. This con.
junction may be visible through a good
telescope il the conditions prove favorable
for observation the planet and star will seem
to the naked eye, or even il viewed through
a spy-glaas, to collide.
Jupiter is evening planet throughout the
month, but too near tho Sun to DO we'll seen.
Saturn is now morning planet and rises an
hour and half before the Sun. At the
close Of the month he will rise three hours
ahead.
Uranus passes on the Both within two
minutes OF the star Beta yirginus. The
nearest approach takes place in the daytime,
but the planet and star will be close enough
to form an interesting spectacle in the tele-
scope on the evening of that day.