Richmond daily times. [volume] (Richmond [Va.]) 1850-1853, 1851-05-08
Correspondence ofthe National Intelliqencer.

Correspondence otFhe National Iutelligencer.
| PARIS, April II.
On Monday the Assembly voted one million two
hundred thousand dollars for the completion of the
defences of the city harbor and road of Cherbouro
This military and naval station, within few
leagues of the English coast, and commandpg the
entrance of the channel, is rightly deemed one of
capital Importance. 1t is now very strong. but
additional expense must be incurred in order to
prevent rapid deterioration. All the Governments
of France, from Louis XIV to the present day.
have been alive to its importance, in case of war
with England. Napoleon called it san eve to
see, and an arm to strike" The round sum of
thirty millions of dollars has already been spent
in the building up of Cherbourg.
A report Just published shows that the number
OF dispatches transmitted by the electric telegraph
during the first month gifts establishment (March)
was 30l, producing an aggregate receipt of $6o6.
1t is not stated how many of these DISPATCHES
were forwarded by Government These would
be seen, fancy, to constitute large proportion
OF the 30l. During the first two weeks the re-
ceipts did not exceed 500. 1t would appear,
then, that there has been manifest improve
ment.
AT the sitting of the 7th instant, M. de Tes.an
communicated to the Academy of Sciences note
describing mode devised by him of varying the
experiment of M. Foucault, by means of which
the apparent movement, the measurable velocity,
may be double of that in the experiment as exhi-
bited by M. Foucaut:
Suppose, said he, ga rigid bar, suspended at its cen
tire OF gravity by UNFINISHED thread suppose the bar
relatively to the horizon. in state orepose will have
then, like the horizon direct rotary movement about
the vercathat is to say about the thread of suspen-
son Suppose then that the bar without departing from
the vertical plane which contains it, should operate
hv,r, hsnht Tho q
ends should be exactly reversed-the absolute amount
and direction of TIM real velocity of each one of the
points OF the bar about the vertical will not be chaneed
but, as each point will have changed sides in relation to
the vertical, the result will be that the real movement
about the vertical will be effected in direction inverse
OF what it was at first that is to say, it will be retro
grade and will have the same absolute velocity as be-
FORE The velocity of the relative movement with re.
gard to the horzon-that is to say its measurable veo.
city-w then be double of that of the real movement
Of thai horizon, and equal to the velocity of the hour
tude."
M. FRANcHor addressed to the Academy note
upon the same subject. His idea is to proongin-
definitely by means of clock-Work, the vibrations
of the pendulum used in the experiment of M
Foucault. The published minutes of the proceed.
ings of the Academy do not describe the mechan-
ism, which would be difficult to understand with.
out the aid of diagrams. Suffice it to say, that
clock-work is contained in the interior of the
sphere of the pendulum; and thus the apparatus,
having in certain respects the appearance of
pendulum Brequet, differs from it in the essential
particular that it receives an impulse absolutely
independent of the direction of the first oscillation.
When this note was read, M. FAYE remarked that
M. Franchot's notion of effecting, by means of
internal clock-work, periodical displacement of
the centre of gravity, and thus prolonging the os
citations of the pendulum, was communicated to
him by M. Foucault himself some time ago, at the
very commencement of the experiments made at
the Observatory. The Academy ordered refer
ence of the notes of MN. de lesson and Franchot
to special committee composed of Messrs. Ba-
bnet, Pou llet, and Despretz.
ought, perhaps, to have added in my last in
order to complete the description of Foucaut's
pendulum, that the thread by which the weight is
suspended is composed of steel wire of 10 mil
lemetres (OO5905 inch) in diameter and that,
though the top of the dome of the Pantheon is, as
mentioned, 26S feet above the pavement of the
place, this wire, stretching from the interior high
est point of the dome to within two or three feet
of the marble floor, is only 22O feet in length.
Capt. Bonnard, of the French Navy, Commssa-
ry of the Republic at the Island of Ta had the fe-
ctous idea of sending one Of his subordinates to
Honolulu, Sandwich Islands,) for the purpose
of observing there the total eclipse of the sun of
the 4th August, 1850. M. Arago, to whom the
report OF the observations made upon that occa-
sion was forwarded, submitted it on the 18th inst
to the Academy. The illustrous astronomer an
nounced his intention TO compare these observa-
tons, point by point, with those of the total
eclipse of lS42, and afterwards to make public the
clear and precise consequence which he might
deduce from the comparison.
The French papers are publishing an extract
from the "Travels in France" of Arthur Young,
in 1857, to prove that the original invention of the
Electric Telegraph belongs to France. 1t would
seem that one M. Lomond, an ingenious
French mechanic, had an electric telegraph in
operation between distant apartments of his house
upon the occasion of Mr.. Young's visit to Paris
in the year above mentioned.
AT the sitting of the Academy of Sences on
last Monday. M. NORM, Director of the Conser-
vatory of Arts and Trades in Paris, read paper
intended to prove that the invention of the steam
locomotive also belongs to this country, being due
TO an engineer named Cugno. His locomotive,
destined for ordinary roads, was constructed in
TITO, and deposited at the Conservatory in 1901.
The machine was intended to convey four per-
sons, and moved at the rate of six miles per hour.
Trials were had in presence of the Duke of
Choiseul and the then Minister of War, which
gave so much satisfaction that new engine up
on larger scale was ordered by Government to be