The Charleston daily news. [volume] (Charleston, S.C.) 1865-1873, 1869-06-30
OCEAN TELEGRAPHY.

We find the following interesting account OF
the working of the Atlantic cable in recent
lecture by the Hon. William ]. McAlpne, on
the subject Of Modern Engineering :" 81
Telegraphy may with propriety. be consid.
cred one OF the branches Of engineering, and
1s peculiarly OF modern development. A clever
writer says that it may be read by each OF the
five senses. NOn land lines each signal is made
by suspendiDg the fow of the electric current
ior @ Two different intervals of tune called 'dots
ders constitutes the alphabet of the telegraph.
When these ale printed they, are read by
''slght," but ordinarily the operator reads them
by "sound" as easily as musician reads the
Operato has no instrument he will grasp the
WIRE IN his hand and read the signals by sfeel-
ing" the intern ssions OF the Aow Of the cleo
tr1o current; In like manner by placing Che
lnterCaisslon. hut this is q dangerous expert.
mec6. And It'll said that the electricity can
be made to dissolve q chemical and produ,e q
can be read by ''smelling, )" but Tor this do not
vouch. believe that the method OF signalling
Through the Atlantic cable is known in detail
to but few persons. The operation is exactly
reversed from that OF the land wires.
The gutta-percha covering 81 Che copper
wires, under the pressure Of great depth of
water, becomes an absorbent of the electricity
wh1ch ~ ls beng set through them to the extent
wave OF 10 per cent. crosses the ocean (17OO
a,es) in two secon ., and IL would be followed
Dy succession OF waves from the restoration
been absorbed by the gutta- peroha in impulses.
and the signal would be repeated like eohoes
and produce not only confusion, but great de-
lay. To remedy this Professor variey nitro
quo Q key. which sends alternate currents,
positive aud negative. at such intervals as
allow the first wave of 10 per cent. 10 pass for
ward, and then that portion absorbed by The
covering @ y; Is ne1ralized BY it's opposite and the
pair OF currents. The battery ussd Is q very
small one. three, OF Daniel,s cups,) and the
signal being 10 per cent. Of this small current,
ments in nse on land. The instrument used
consists OF q minute polarized needle, suspend-
ed on single strand OF spider'E web, or one
minute needle 10 placed an almost microscopic
mirror, winch reflects single ray Of ii Z ht from
q powerful lamp. ,s.,S'''I- =
The currents Of electricity affect this needle
time corresponding TO that occupied in the sie-
nal OF the land-line. the same kind or alphabst
being used in Doth cases. The receiver mot
operat1r) sits in dark room. aud the small
mirror reflects the ray OF iight upon q piece of
white paper before him, ON which. ok line
is drawn, TO the right and left OF which the
nsnt is alternately reflected. The receiver
1eaos ee tnese sianal. by "sight and transmits
tnem lnto another person, placed outside OF
me q rk room; by means OF an Ordinary in-
strument A short time since General Rev
noids toa me that he had sent 8 message,
without either wire or cable, ntnety-tyyo m,les
across an arm VI L ke Superior. BY means OF
tne heho,rope or tmrror and on the return Of
tnis messenger. wno had Deen sent with o
written copv, be found tina, the heliotrope mes
sage g. had been received, underst God and obsyed.
He mad two assistants, who had been tele-
graphic operators. who had for whole sum-
n1er Deen amdslng themselves IN taking 10
each other with these Instruments, though
they were stationed ten twenty. or thirty.
niles apart. When the rebel General Morgan
OHIO ne captured one of my operators. and
SGmpeled coz hin TO telegraph, In General Lew
'Wauaoe's Dame to Cincinnati asking how
many regular troops wsre In that oity.. Morgan
Tesd i,s Dy sonnd, and therefore tho opera. or
1id not dare TO intimate that he wss under
durese, and con only venture to add an extra
initiaI 70 hts own signature. The receiving
operator at Cincinnati knew thAS Morwap vas
~ that ne'ghboIhood. and snspeoting from
ae sx!Sa initial letter that all svas oIrig IT,
replied greatly exa0 yevReinR the force OF rcgu-
% iars and the consequence was that More. IN
cnanRed his route 70 q c'rcuit Of twenty mica |
beyond the city, an thus saved is from n suOk. |
and the probable loes OF millions Of dollare.