The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1885-04-02
THE TALKING WIRE.
description Of the Mutual Telephone
COInpany's system.

P"HI' represen aatIVe of the z. 9. ADvEF
IIsER yesterday visSted the central Office G
sAe company, in the wo-story brick buildin
erected for their use 3. n the corner of Alake
and Merchant streets and was shown tn
practical working of the overhead cabl
system which the r,dutusl Company ha
adopted
The second storv of the building i
arranged with refe renee to the needs of tn
company the frsi il floor being available TO
store purposes,
ne rooms % q the second floor are of goot
slze' those on1Ethe left of the hallway, which
divides tn g second floor into two parts
Oelh9 use cd to store the instruments and
''her raf 4terial of the company; also, as an
A'f4 operating room, an Office for tho
t,erintendent, and a work room where in.
Struments are tested and repaired. On the
right hand side of the hall are Mr.. Pratt's
private apartments and the operating rSom.
Being introduced into the latter, and to
the lady operator who sits at the switch
board intent upon her work, our representa-
tive then examined with interest the
arrangement of this center of telephone in
telligence.
The cables that radiate from this build
ing throughout the city are brought into
this room through ports in the wall near
the ceiling, and are then carried above the
ceiling, out of sight, to point where they
come down to the back of an upright screen
standing behind the switch board. The end
of each cable is held in a cylindrical clamp,
and the lead covering being stripped of for
a short distance, the individual copper
wires that make mp the cable are properly
connected, by means of clamps on the back
of the upright screen, to the switch table in
! front Of the operator.
And now a word in reference to the
cables themselves. II should be understood
to begin with that the use of overhead cables
in telephony is for the purpose of doing
away with the network of individual wires
that would otherwise concentrate at the
central Office, and be a source Of incen-
yenience throughout the city. This is the
primary effect sought for. But it is also
claimed that though the first cost of
the cables is greater than that of an
equal number Of single iron wires,
they last much longer, and as at pres
emit constructed are quite as free from
" induction as the single wires stretched,
they are close to each other on the poles.
1t may not be out of place to explain what
is meant by '' induction" It is that ever
active desire which an electric current has
for going back to the earth from which it
may be said to have been drawn and pressed
into mans service. Electricity is the most
subtle of all the natural agencies that work
for US, and at the very first opportunity it
has it escapes from the line it is induced to
travel upon by by the facilities afforded it.
1t is ever seeking the shortest route to get
to the EARTH and if i'll traversing the slender
copper wire to whiclI it is assigned it finds
the minutest crevice, it will glide out and
take the nearest route home. Hence it fol-
lows that if a number of wires are grouped |
closely together, there may be some imper- |
lection in the insulation that allows the |
electric current to leave q wire and if it |
does So it will so to the other wires if it |
can.
The cables in use by the Mutual Company
are as carefully made as they can be. Each |
copper wire, about one-fortieth of an inch in |
is closely wound around with cot |
ervation. From twenty to thirty of these |
wires are then grouped around central one |
about one-eighth of an inch in diameter, |
and the whole is covered with a wrapper of |
cotton thread, parafine-coated. This rope |
of wire is then drawn through lead pipe, |
and mere parafine is forced into the pipe, |
filing every interstice. This completes the
cable.
Carefully as this cable may be made there
is still some chance Of the current in any one
wire being induced - to leave it and go to
an adjoining one. This would cause con-
fusion and interfere with the transmission of
the vibrations that are the result of sounds
made by the sender's voice, and resolve
themselves into sound again on the auditory
nerves of the listener.
For this reason the comparatively large
wire is placed in the center. tits but lightly
and has no connection with any
1t is grounded at each end
Of the cable in which it is embedded, and
lies in wait for any electricity that may es-
cape from the surrounding wires. By its
superior size and comparatively imperfect
it induces such currents to select
It as their paths instead OF one OF the other
wires for transmitting messages. The
superficial area Of this induction catcher"
as it is called, is greater than that of all the
wires combined.
The cable thus constructed is found to be
rs free from induction any system of
single wires, and as for the ''cross talk
that always occurs, even in the very best
regulated families of telephone wires, there
IS no more on the Mutual line than on any
other. What there is is proved to be due TO
The accidental interference of the open iron
wires with each other, because the amount
II sucn cross talk varies with the condition
If the atmosphere, which does not affect the |
cables, they being protected by their paraf-
inc coating and lead covering.
Behind the screen already referred to is !
series of shelves on which are arranged the
ars of the Office battery. Near a. hand is !
BOARD arranged so as to test the condition at
my time of the calling lines, delicate gal ]
showing by its movements
whether any or all the lines are in order.
Suitable arrangements are made for call
ng the operator at night, and instruments I
# the most approved pattern are being put {
u to subscribers houses at the rate of ten