Delaware gazette and state journal. (Wilmington, Del.) 1883-1902, 1899-07-06
THE SKIES IN JULY.

In course of the month of July the
moon will pass through her phases,
as follows: New on the 7th, first
quarter on the 10Th, full on the 22d,
and last quarter on the Goth. On the
10th she will be in apogee and on
tho 23d in perigee. Since the 21st
of June the sun has been slowly moving
southwark. On the 1st Of July it was
90 degrees, minutes and 12 seconds
and on the last it will be little over
is degree, 16 minutes and "a seconds
north Of the equator, traversing during
the month an arc of a little over b
degrees. The exact position of the
sun north and south of the equator,
or, to use technical term, its dec
lination enters into SO many as
Economical computations and is Of SO
great an importance that the Nautical
Almanac gives it for every day in the
year with a correction for every hour.
The problem involving the calculation
of the suns rising and setting, con-
sequently the length of the days and
nights, of the points of the sun g rising
and setting ON the horizon, of the time
when the sun will begin and cease
to shine on the north and south walls
Of buildings, Of the length of twilight,
all of these and many more requires
q knowledge Of the declination, and
1t becomes, therefore, Of great import.
ance to compute it with great accuracy,
and to lay down the results in that
book SO indispensable to the mariner
and the almanac makers-the Nautical
Almanac, which is prepared under the
direction of the professors of the
United States Navy. For many years
| this important work has been directed
by that fine mathematician and as
tronomer, Prof. Simon Newcomb, to
whom the great perfection of the
| American Nautical Almanac is chiefly
due. While Mercury will he in Gemini
at the beginning of the month, ii
will be in Leo at its end. Venus will
| at first be at Taurus, but later in
Gemini. Rising between 3 and o'clock
in the morning, she will shine as morn
ing star and be visible for some time
even after the morning twilight has
considerably advanced. Mars in still
in Leo. AT the beginning of the month
this planet will set about 1890 in the
evening, and toward its termination an
hour sooner. AS soon as the first mag.
nitude stars become visible Mars may
be seen little less than midway be.
tween the meridian and the Western
horizon, conspicuous by its intense
redness. Jupiter is still lingering ir
Virgo, quite closely to Spica, the mosi
conspicuous star in that constellation
This beautiful planet will be visibl,
rs evening star until about midnight
Saturn is in Sagittarius and not yer,
far from a portion Of Ophiuchus, con
stellation to be described farther on
This planet will be on the meridian
at about O'Clock. Uranus is in Scor
pic and Neptune in Taurus, but oil
account Of their immense distance the,
are not visible to the naked eye, though
very keen eye may catch glimps
of Uranus on cloudless and moon
less night.
The correlation of sciences has be
come especially manifest In the case o
astronomy, the astonishing achieve
ments of which within this uentur.
are principally due to the msrvelou
discoveries in the physical and chemi
cal sciences, the greater perfection o
mathematical methods and the appli
cation Of the principles Of analytica
mechanics, all of which have lent thei
powerful aid in making astronomy on
of the most perfect in the whole ARA
Of sciences. Photography, especially
has been of inestimable benefit 70
astronomical observations and produces
results. that might not have been foun
by any other method. Prof. Pickerin
of Harvard University, has been on
of those who paid much attention t
observations by means of photography
especially in observations Of the eclipse
OF the satellites Of Jupiter. Photograph
J has been extensively applied TO oberva
ton of the moon, the nebular, the sofa
corona, the solar spots, and the transi
of Venus In making charts of tn
stars, which for many purposes ar
more convenient than mere catalogue:
photography has played, and is det
tined to play, a still greater par