The evening times. [volume] (Grand Forks, N.D.) 1906-1914, 1907-02-19
The Range Of Talk
Is Being Extended
Long Step Taken Last Year Towards Tele
Difficulties Already Overcome and Problems the
Future Must Solve.

Not the least among the achieve
ments Of 1906 in the Industrial world
Is the long step taken towards maxi
ing transcontinental telephony an ac-
complished fact. Thirty years ago
people scoffed when Alexander Bell
told them that by means OF the tele-
phone they could talk from one END
OF their town to the other. Today we
talk under rivers and harbors, over
the highest mountain tops, from the
lowest recesses of the deepest mines,
through snow-drifted wildernesses ana
across sun-baked deserts.
The work done in the past year In
Fastening the day when New York
can talk with San Francisco has been
that of development rather than that
involved in the making Of spectacular
discoveries. In bringing about present
day conitions under which q man can
talk by telephone more than half way
across the continent, there has been
a steady succession of improvements
In the telephone art many of which
have received little attention from the
telephone-using public.
In its early days the telephone used
the same sort of iron wire that the
telegraph employs, and the circuit
was completed through the ground.
This works very we'll for short dis
tances, but the transmission of every
incubation of the voice is much
more delicate matter than transmitting
the taps of telegraph key. The first
step, then, toward extending the dis
lance over which messages could be
sent by telephone was the invention
of process of hardening copper wire
SO that 1t would not stretch from its
own weight when strung from pole
to pole. And 1t is an interesting fact
that Thomas B. Doolittle, who invented
the method of doing this and thereby
made possible the use of copper con-
ductors in all electrical industries, is
still an active member of the engi-
neering force Of the Bell system which
has devised practically every improve.
.ment in telephone apparatus and
equipment since'Dr. Bells fundament-
al discovery
The first copper telephone wire was
about the size of the iron telegraph
wire it replaced. With improved long
distance" instruments, such as are
now in general use for all kinds OF
service, conversations can be con-
Quoted over wire of this size for about
$50 miles with what the engineers
call standard transmission" BY in
creasing the size of the copper strands
on their long distance lines, the Bell
engineers have more than doubled the
early limits of successful transmits
sion.
1t might seem as if all that was
necessary would be to keep on In
creasing the size of the wire indefi-
nitely, and thus extend the rangs OF
talking. Even were it not for sc1en-
tific difficulties, the cost of the metal
alone, at its present high price, for
much heavier conductors than are
now used would be practically pro-
hibitive. Neither can transmission
over greater distances be secured by
means of more sensitive apparatus,
for if the telephone instrument were
made more sensitive than it is, it
would become so microphonic, as it is
called, that noises that could reach
the diaphragm would cause such
tumble of sound that the words of
telephone message could not be UNDER
stood.
So the problem before the engineers
has been to find way to prevent the
telephone current from "decaying"
during the journey of message over
the lines. That is, the engineers have
sought means to counteract the in
evitable loss of efficiency in the cur
rent and to keep it as near as possible
at its original strength. Two methods
of doing this have been tried. Sepa-
rateiy they. have worked out we'll;
but as yet they have not been applied
commercially to the same line.
The two devices that promise so
much for the extension of the range
of long distance talking are the load
ing coil and the repeater. Though the
ends they accomplish are, to certain
extent, the same, the principles on
which they work are entirely different.
When the electrical current from the
transmitter Of one telephone starts
out on its journey to the receiver of
another telephone thousand miles
away, say, it loses strength very fast,
away by degrees until finally
it becomes too weak to reproduce VI
brations distinctly. The loading coil
which was invented by Professor
1. Pupin, of Columbia Uni
versity, acts as sort of stimulant.
1t consists of an iron core upon which
is winding upon winding of fine wire
which the talking current is passed IA
such a way that it is strengthened
against the decaying processes and
maintained at a level high enough to
give satisfactory transmission. These
coils are attached to a line two, four
Or maybe eight miles apart, and their
use approximately doubles the range
of' the telephone.
The repeater, which is later in
1ention, produced by one of the Bell
engineers, operates very differentl'.
As its name signifies, it actually re-
beats the message, which, coming
through receiver. reproduces itself
on transmitter. This
FLOWS at putting new current into the
inc, just as the original current is
Introduced at the transmitter of the
telephone. The result is
to start the message all