Public ledger. [volume] (Memphis, Tenn.) 1865-1893, 1873-07-26
PUBLIC LEDGER.
once; No. 10 Madison Street.
AdEMP HISS
saturday Evening, July ae, IS7s.
AN INTERNATIONAL MERIDIAN.

The adoption Of an international me
ridian, il is reported, is about TO be dis-
cussed in the French Academy OF Sci
ences. with the prospect that the circle
of longitude passing through Greenwich,
England. will be adopted. The conelu-
sion is hardly warrantable since the
meridian passing through Paris and ex-
tending far south into the sandy plans
of Algeria, was calculated and meas
ured with extreme accuracy ana NJ =
great expense by the most celebrated
French mathematician, aud It Is very
improbable that the French Government
would be so deficient in pride as to re
iect the results of the labors OF its men
of science and adopt the English stand
ard which was measured northward
through Scotland, and was subject TO
errors arising from the deviation OF the
plumb line caused by the high noun
tains OF that country. Paris is only
two degrees twenty minutes west oil
Greenwich, and this difference OF longi-
tude is too small to afford any argument
for measurement Of a new meridian
through France. The true state Of the
case IS probably this. Trouyille, rainy
seaport near the mouth OF the Seine,
is seven minutes east OF Greenwich,
and the Academy proposes to ex-
tend the meridian to this place
and there erect two columns in the line
OF Longitude so that vessels may correct
their instruments and chronometers &C
cording to English time. II is asserted,
however. that an international meridian
would simplify scientific works, and
would be serviceable in the signaling oil
latitude and longitude between ships at
sea. These advantages are oyerrated;
latitude is reckoned from the equator,
and the addition OF a single letter Il. or
P. to the signals would show whether
the meridian was that OF Greenwich or
Paris.
The above is from one Of our ex-
changes. Many years ago Commodore
Maury, then in charge OF the National
Observatory at Washington, wrote pa
per urging the adoption Of some prime
meridian to be used by all nations, and
recommended that of Greenwich. The
fact that the French have carefully
marked the line of their prime meridian
nto Algeria, or that the meridian OF
Greenwich has only been run into
Scotland, and that incorrectly, has
nothing to do with the case. IL
neither had ever been run anywhere,
they would answer just as good pur-
pose for a starting point as now.
In other words, Memphis could be
used equally as we'll as prime meridian
as either Greenwich or Paris. Cadiz is
the prime meridian of the Spaniards,
Berlin of the Prussians, st. Petersburg
of the Russians, and Stockholm OF
Sweden and Norway, which will show
that it is not necessary to set up monu-
ments on the line OF the meridian in
order to make it useful to the navigator,
and which will further show that when
passing vessels exchange their longitude
(they never ask for the latitude); more
letters than P. or G. are necessary,
neither of which, however, are needed,
as ships in meeting always display their
colors, which indicates their nationality
and the prime meridian from whence
they calculate their longitude. Longitude
is calculated by the difference of time at
two given places. All ships carry chro-
nometers to indicate the time at a GER
tain primary meridian; Just as Mem
phians frequently, when absent from
home, let their watches continue to keep
Memphis time. When the longitude is
desired an observation of the sun is
taken, and at the very instant the alti-
tude is observed the time to second is
taken by an assistant of the observer
from the chronometer. The observation
gives the true time at the place, and the
difference, reckoning one hour as equal
TO fifteen degrees, is the longitude. The
setting up two towers in the meridian at
Trouville would be Of no more practical
benefit than chopping a couple Of notches
on the sane number Of oak trees below
Fort Pickering.