The sun., 1890-11-09
HOW MESSAGES ARE CABLED.
WIRES IRON EUROPE TO BROAD
STREET. VA BROOkLYN BRIDGE.

sTxEET. vfA BRO0xLYN BRIDGE
No sssaAsrs Ussa. Bot the Operator Aeress
the Oessa Whites the WORDS Here with
Ink aaa with Pen sappiisd Here
All We Farnish 10 she Paper.
The manner In which messages are sent and
received over the transatlantic cables between
this country and Europe 10 very different from
that In which kilograms are transmitted across
ths continent on land lines. The two systems
OF submarine and overland tsleGraphy. al
though but two departments OF the one science.
and In many ways closely copnectsd. are yet
entirely different one from the other. The ap-
paratus. tho methods Of signalling. and even
the tsleGraphic characters that form tho alpha
bot. are altogether dissimilar. and the most
expert land-line operator would be - much At
Q loss In an attempt to send message over the
cable as would locomotive engineer.
Instead OF the loud clattor and din and the
incessant clicking Of brass saunders. so famil-
lar to every ono as the distinctive character
istic OF telegraph ONCE there Is In the cable
ofnce almost absolute silence. 80 far rs the
manipulation OF the instruments 10 concerned.
Instead OF tho messages being ratified noislly
of the tongue OF brass sounder into the ear
OF tho operator. they arc silently written
By q slender. mysterious finger on
ribbon Of white paper. which passes
quickly before the OPERATORS eyes. Tho
paper ribbon. about half an inch wide. Is
unwound from roll and drawn along By
aossless clockwork over sheli-liks desk In
front Of the operator. A delicate glass tube, no
thicker than an ordinary needle and crooked
like bent foreanger. which is suspended be.
tween the polos OF large upright magnet,
moves nervously to the right and left on tho
ribbon being drawn beneath Il. aud traces In
q thin line OF blue Ink characters that look
somethng like tho markings on barometer
chart or the quotation board OF tho Gold ana
Stock Board.
Tho instrument 10 tho THOMPSON eiphon
recorder an elaboration Of tho Thompson mir
ror instrument once generally used on sub
marine cables. with which messages we're read
by the flashing or wavorinR OF little dot OF
light on = graduated scale. In the recorder
the principle Ia the same. but the movements
OF the fash light arc recorded IN the paper
slip. On account OF the perfect Insulation OF .
submarine cable and for various other techni-
cal reasons 1t ia only necessary or safe to uss
Q very small amount Of electrical power to
transit messages through It. About thirty
volts Is all that 10 required to transmit mss-
sage under tho Atlantic from America to Eu.
rope similar force OF ourreht on a land line
would barely carry u message from the Post
once to Yonkers.
II the comparatively clumsy instruments
used for land tele9rapby were used GU the At
lantic cables scarcely one word minute could
be transmitted. whlle with the recorder
speed OF from flfteen to twenty-five words
minute is regularly maintained. The mirror.
which 10 still used on some cables is the most
delicate and perfect telegraph instrument ever
invented. 1t Is simply n small needle sus-
nandad in n m aunetiC coil. delicate and fraQiie
nsedle S i Is eiees oi watch spflns three .eieb.hs
small p[ec: ,oi sllvered glass affixed
but one and q half grains. The Instrument is
placed In . dark room. and Q ray OF Light from
alamp 10 centred through q lens on the mirror
cable enter the magnetic coll and cause the
%sons 70
actors. These minute vibrations are road of
By an operator who calls out sach 4; word M ss he
14ss Tbe prinsipe o, the mirror is. in tho main.
pal cables. but In place Of the small sol
large upright MAGNET u used and modiiea;;
S Ct t so poes Rss u
place Of the ailvered glass: Ono end Of the
osRs9 .n 5Si Il fae
Of The surface of the white paper ribbon which
through the siphon BY an electric process. and
as the tube moves to the right and
movements on the paper ribbon. As the
riboon passes before tie operator the markss
marks correspond in q sense to the dots and
the. downward to the dashes Of the Morse
alphabet Owing 70 the psegltarities Of
bef.. which cannot. be trsnsmi itted on the 70.
eprder, an entirely different combination Of
Unlike the Morse. the dots apd dashss Of which
are always alike. or should b. unless tho
operator II ham," the cable signals vary
cable. and from many other causes.
The drawings given below are reproductions
Of transatlantic cable slips. or ribbons The
MESSAGES traced thereon. were sent over the
cable by which THE Suns cable news Is re.
oetved from Europe: