New-York tribune., 1907-01-27
Done in the laboratory
Why Not in Daily Busi-
ness?-The Reason.

Not the least among the achievements Of 1905 IN
the industrial world is the long step taken toward
making transcontinental telephones an accom-
plished fact. Thirty years ago people sconed when
Alexander Graham Bell told them that by means
Of the telephone they could talk from one end OF
their town 10 the other. To-day persons talk un-
der rivers and harbors. over the highest mountain
tops, from the lowest recesses or the deepest
mines through snow-drifted wildernesses and
across sunbaked deserts.
The work done in the last year in fastening the
day when New York talk with San Francisco
has been that Of development rather than that IN
volved in the making OF spectacular discoveries
In bringing about present-day conditions under
which a man talk by telephone more than nan
way across the continent there has been a STEADY
succession of improvements in the telephonic ART
many OF which have received little attention from
the telephone using public.
In its carly 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 well for short distances. but the
transmission of every modulation OF the voice is
much more delicate matter than transmitting the
taps OF a telegraph key. The first STEP then, tow
ard extending the distance over which messages
could be sent by telephone was the invention of
process cr hardening copper wire so that II would
not stretch from its own weight when strung from
pole TO pole. Thomas B. Doolittle invented the
method OF doing this and thereby made possible
the use Of copper conductors in all electrical in
dustr1es
The first copper telephone wire was about the
size Of the iron telegraph wire IL replaced. With
improved long distance instruments. such as are
now in general for all kinds Of service. con-
versations can be conducted wire of this size
for about $50 miles with what the engineers call
standard transmission" BY increasing the size
Of the copper strands their long distance lines
they have more than doubled the early limits OF
successful transmission.
II might seem IL all that necessary would
be 20 keep on increasing the size of the wire IN
definitely and thus extend the range of talking.
Even were II not for scientific difficulties the cost
of the metal alone. at its present high price. for
much heavier conductors than now used would
be practically prohbitive. Neitaer transmits
sion over greater distances be secured by means
OF more sensitive apparatus for II the telephone
instrument made moro sensitive than II Is II
would become so microphonc. it is called that
noises that could reach the diaphragm would cause
such tumble OF sound that the words of tele
phone message could not be understood.
So the problem before the engineers has been to
find a way 10 prevent the telephone current from
'decaying'' during the journey OF message over
the lines That is. the engineers have sought
means counteract the inevitable loss OF ef-
flciency in the current and 10 keep II near as
possible at ITS original strength Two methods OF
doing this have been tried. Separately they have
worked ont well; but yet Shey have not been
applied commercially TO the same line
The two devices that promise much for the
extension OF the range OF long distance talking
the loading coil and the repeater. Though the
ends they accomplish 10 a certain extent, the
same the principles which they work
tirely different When the electrical current from
the transmitter OF telephone starts out on its
tourney 20 the receiver of another telephone
thousand miles away, say, IL loses strength fast.
sinking away by degrees until finally It becomes
too weak TO reproduce vibrations distinctly. The
loading coil. which was invented by Professor
Michael ]. Pupin. OF Columbia University, acts
a sort OF stimulant. II consists OF iron
upon which is winding upon winding OF fine wire
through which the talking current is passed in such
a way that it is strengthened against the decaying
processes and maintained at a level high enough
10 give satisfactory transmission These coils
attached TO line two. four maybe eight miles
apart and their approximately doubles the
range of the telephone
The repeater, which is a later invention. operates
direreutly AS it's signifies IL actually
meats the message. which coming through a
ceiver reproduces itself automatically a trans
mi.ter This allows Of putting current into the
line lust as the original current is introduced at
,,a transrnitter the subscribers telephone. The
result Is practically 20 start the message all over
again with fresh lease Of life. though naturally
,be force that carries IL cannot be made quite
~ood os new repeater in the middle of long
S,s,ance circuit extends the range Of talking about
90 per cent
work which tend TO delay rather than hasten the
extension OF long distance service. The ideal trans
mission would be obtained over lines OF heavy cop
Der wire strung upon poles. In practice however.