The evening times., 1896-02-04

and pcri.ree on the 18th.
The sun is on the first of the month Il
deg. 9 min. sec, and on the last deg.
80 min, IS sec. south of the esuator, and
consequently approaching the equator at IA
more rapid rate than last month. During
the month the suns motion in right asccn-
sion is nearly % 4 deg.
On the 18th of the mouth an annual solar
and on the 2Sth a partial lunar eclipse
will take place. Solar and lunar oclipscs
are essentially different from each other.
In the former the moon interveneS between
the sun and the earth. hiding the former
from our view, and, therefore, the Ehe-
nomenon is really partakins mere of The
character of an occultatiOn than an eclipse,
while in a lunar eclipse the moon pluD:es
into the shadow OF the earth. and is. there
fore, itself affected, which is not the case
in Il solar eclipse.
Were the eye of the observer at the
vertex of the cone which the moons shadow
forms. the disk of the neon would cover
that of the sun. The radius OF the neon is
sometimes less, on account OF her varying
sometimes less. ON account Of her varying;
distance from the earth.
In the former case the eclipse is total
10 All tHoSt Dldtt> Nn.fih ci
the shadow as it crosses the earth: in the
latter case the eclipse is annular TO places
which lie near enough the path of the axis
of the shadow.
RING ON THE SUNS DISK.
The word annular comes from Il Latin
word meaning ring" because the moon
does not quite cover the sun. and thus u
ring is formed on the suns disk. Neither
OF the two eclipSes occurring in February
can be seen here. The planet Mercury will
be at the beginning OF the month in Aquar-
iuS. but 1T the middle and end in Capri
cornuS.
Venus will be in Sagittarius, but toward
the termination OF the month pass into
two planets will not be at gIeat dis
tance from each other.
Both Venus and Mars shine as morning
stars the former rising at about I:3O
O'Clock in the morning and the latter a
quarter OF an hour later Jupiter is in
Cancer and will shine as evening star until
nearly O'Clock in the morning.
Both Saturn and Uranus will rise soon
after midnight and shire as morning stars,
though the latter requires a magnifying
glass to become visible. Saturn is in Libra
and Uranus in scorpio. while Neptune is
still lingering i'll Taurus and might be seen
as evening star with the naked eye did not
its enormous distance preclude the posi-
bility.
A little before the morning begins to
dawn the earlier riser will see the beautiful
spectacle OF the two brilliant planets,
Venus and Mars above the eastern horizon,
Saturn right overhead and Jupiter on the
point OF vanishing beneath the western
horizon; Picture the beauty OF which is
enhanced by the proximity of Venus and
Mars Venus can be distinguished from
Mars 10y her greater brightness and some
what higher position in tie sky, while a
diStingu shing feature OF Mars is his Gcry
red color.
THE DOUBLE STARS.
II was but a century and a ha!f aGo that a
new feature of tie sidcreal world was dis
covered which added greatly TO the variety
and interest Of tie science of astronomy and
opened a new field for that wondcrfnl in
strumcnt-thc telescope. II is lie uIPose
to furnish in this article 4 de- cripiion. which
must needs he brief, of this E,w ficid-tbe
double stars which anterior TO the invent ion
of magnifying lenses could not hut he an
and under the circumstances
fact
1t is necessary to make 4 discrimination
between stars that are opticaliy and physi-
caIly double When we look a two objects
which are at such a distance as to make a
correct estimate Of ii uncertain, they may
appear as very near each other. and even
as one object. though one may be at a great
distance behind the other: in other words
both may be very nearly OF altogether in
the same line of vision. This is exactly the
case with opticaly double stars.
They may be a t an enormous distance from
each other but so nearly in the same line of
vision that they seem to touch each other.
and to the naked eye appear as one star.
or the 10000 couples OF double stars now
known, there are comparatively few that
are Optically double.
By physically double stars are understood
those which are physically connected and
form system of two suns. which by virtue
Of mutual attraction revolye about each
other, or to state it more strictly, about
heir common center of gravity. proving the |
'act that Newton's great law of gravitatiOn |
S not confined to our own solar system. but |
.xtends to the whole created universe in its |
nfinitude |
Such a system of suns revolving about |
,ach other is also called a binary system |
md double stars thus physically connected |
re called binary stars. The reader who is |
ware of the stupendOus stellar dis |
ances can easily imagine that the dis
inguishing of Optically and physically |
ouble stars was 10 easy matter. as ii must |
Il necessity require long periods of time
o catch such stars at their proper motion. |
II is certainly 10 be considered Il great |
riumph of the human mind. and a valid 4
estimony of what it is able TO accomplish,
hat such binary systems have not alone
een discovered. but that the periods Of /
evolution have with more or less accuracy
cen established. especially if we Ike into |
ccount that here we have not To deal with
he comparatively near planets of our solar
ystem, but with fixed stars whose dis
nnceS from us must he expressed in light
ears in order to enable us to acquire an
dequate conception of them.
HOW IT Is DONE.
To catch a fixed star at proper motion
equires the utmost patience and persever
nee. the most careful obscrvations~with
ne very best telescopes. and, above all. time.
he most distant of the planets of our
Dlar system. Neptune. performs one cir
nit about its luminary in 1854 years. which
Gems to be Il very long period, and which, |
ldeed, 1t is if 1t is compared with the
eriods of the moon and the planets of |
Iercury, Venus, Mars, and even Jupiter
nd Saturn.
But how finitesimally Snla II Is the dis |
ance of even Neptune compared with the