The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1899-04-06

I4uOSL caD4es, because or eieCtrIcal re-
L.rQaCIon que 10 INDUCTION. Experience
mas SHOWN that onIy IeeDIe but dIsLIncl
impulses at the far end VIII do, ana,
oy i cunning arrangement OF eIectrlca.
devices POSITIVE and negative cnarac-
GERS are sent into the wires in sucn
Succession that they VIII tend TO "'eaL
up" the induction while leaving enough
OF themselves free to go ahead TO MAKE
the signals at the receiving end. That
these feeble discharges may do their
work, delicate receiving instruments,
susceptible to the slightest electrical
impulse, are ready TO translate them
into the several forms OF dots and
dashes Of which letters are formed
| These dots and dashes are not really
such as the Morse recorders of land
lines produce; they are either arbitra-
ry movements or wavering ZINES pre-
concertedly read as such
The simplest form of receiving in
strument, and one which, in expert
| hands, is capable of great speed. is
|
en- The messages are read in flashes
of light thrown either on a screen or
the writing pad OF the receiving clerk.
A flash to the left being a dot" while
flash to the right means a dash"
The speaker" is composed, first, of
a coil of wire with in
drical case. Through the cen
ter of this coil is placed a brass tube
supporting on thread at the inner end
small mirror backed by little mag
net. a semi-cylindrical magnet, sur
mounting the top of the coil and capa-
Bile of adjustment, facilitates centering
the mirror. Now, when a current is
sent into the coil, it, in turn, becomes
| a magnet, but ceases so to be the mo-
ment the impulse has passed through
to the earth. The coil becomes mega
tive or positive as the current or i'm
pulse is negative or positive and just
as the balance of the mirror magnet
is disturbed by the changing character
| of the coil, the mirror is swung light
| ly TO one side or the other When I'M
affected the spot of light falls on
| Zero or center line, on the translu-
| cent screen before the receiving clerk
| If the sending clerk has sent the letter
| "a he has started first a positive i'm
pulse, a dot, "Aand then NEGATIVE
one, dash" and the mirror of the
speaker" throws first spot of light
to the left and then a spot of light to
the right OF the center line, and "a is
read. The letters of the code
in combination, and as many as four
OF these elements go TO form come let
ters, while some numerals require even
more. On short stretches capital mirror
clerks have been able to read as many
as thirty-five five-letter words a min
ute. 1t is needless to say they don't
begin to count the elements of each
letter, but have learned to judge the
letter by the general character of the
signal. The greatest drawback to this
method is the fact that there is no
permanent record of the message and
in case of error or dispute there is
nothing left for reference, and, too, the
instrument could not be read success
fully if worked by one of the several
methods now used for very rapid trans
mission. This led Lord Kelvin, to
whom we are indebted for so many
things, to invent his siphon recorder.
tn, ,i,,Jo h; ,,l1x I0J,o to-
instrument is worked like the mirror
speaker" There is first powerful
electromagnetic, between which is a
coil of wire delicately suspended. This
coil is connected to the receiving end
of the cable, and, in turn, as the cur
rent passing through it TO the earth is
positive or negative, the coil becomes,
for the time, a positive or negative
magnet, and is drawn first to one side
and then 10 the other toward the poles
OF the neighboring electromagnetic.
This motion, by a silken thread, is
transmitted to a very fine glass siphon
connected at one end with a tank of
ink and at the other to a moving line
of paper tape AS the siphon through
the movements of the small magrlet
or coil. is drawn to right or left, OF
the center of the paper tape, a zig-zag |
course is traced, the points or peaks
above the center line being dots and |
those below, the ''dashes.'
The ablists who work at these ser |
nentine'' signals or "cabalistic zigzags
of the recorder are looked upon as the
aristocrats of the Geographic profess |
sion. and they, too, in their turn, be-
come so expert that they read these |
oc of the sinhnn iIISt as we |