The morning news. [volume] (Savannah, Ga.) 1887-1900, 1896-04-12

Or 80 degrees, east of the meridian OF
| greenwich; If it reads o. clock, the vessel
- hours, or 30 degrees, west of the same
uleIlalan. Allowance must, of course, I've
made for the rate" of the chronometer
,Ihus our astronomer is able to place
ms niger triumphantly upon the very
SPOT on the map where the good ship is
salnng, and this masterful achievement
IS only subject to a possible inaccuracy
OF very few miles,
Where the latitude is known more
accurate local ~time" observa ton is made
When the sun is near the prime vertical -
ana IN all cases this must be treated by
Ihe equation of time" for the mean
In the absence of a chronometer the
position or the moon among the stars
serves 10 determine the longitude, the an
Sular Instance being observed with the
| sShtdnt, ana in like manner the moons
aiutude is made TO indicate the latitude.
,.i ne almanac positions of the moon as
RIsw~ed from Greenwich are contrasted
with the positions as viewed from the
Eessei, the whole process, which is rather
S,,I IeIl9us one, being termed clearing a
The stars which serve such valuable
purpose are Alpha Arictis, Aldebaran
A oiiiuIa, Keegulus, Spica, Antares, Alpha
1H{qulIae, Fomalhaut and Alpha Pegast.
Inc planets Venus, Mars Jupiter and
saturn are also made use OF.
1,a IN GiSS,Itain ATTITUDES the north star may
~ S utliINeu IN determining the latitude Ir
II were in the exact place of the mole 81
me .neavens its altitude corrected onlv
II up ana 'refeStion," would be also
5ne lautude. But, as it is now about a
oegree and a quarter distant from the
P, oie ana as the pole itself is changing
Slowly, another table of treatment in tbe
almanac must be consulted W
Inc latitude may also be found nv +ha
-, LUZ VI any OF the planets referred to
Dy uo9ole attitudes of the sun. or bv one
aiutuue taken near noon when tbe time
VI u observation is known; and the Ionef-
s seue may De aScertained by the ohserxSa
elS 3i VI various phenomena such as the
0IhP9SS OF the sun and the moon the oc-
SuIu!tatlohs OF stars by the moon and the
eSipses of Jupiter's satellites AS these
Plvioiield are seen at the same rnoment
IIoui al points on the earth's surface
witnln the angle of vision, the Observation
"a i tlSil furnishes the Greenwich time pre-
uIcteu by the almanac. But to observe the
movements of the little Jovian moons re
lures telescope of fair dimensions. and
~ ndhule THIS on the deck of a Waye-toss-
gu vessel would be a very troublesome OBJ
In the absence of sun. moon and store
the navigator relies solely upon his com,
pass ana the determination of his rate of
speed py the ships log. Each of the 70
pOlnls OF the compass, in whose center
Is Poised the mysterious magnetic needle.
marks an angle of IL degrees and * min
utes, and thus the sailing of the vessel
py oead reckoning becomes a simnle
problem, affected. of
course, by ocean currents, and the "yari-
auon or the compass"
Inc introduction of this benefcent in
Strument reVolutionized navigation and
heralded new era; while the splendid
services OF astronomy have not only made
every part of the world accessible for
purposes OF commerce, but have also ban
1Shed the fears of the untold thousan5s
who 'go down to the sea in shins'5 re1a9
1--WE 10 the disasters inevitable to attempt |
ca navigation in the far past