Year: 1898

page_text: I, ALEXANDER MUIRHEAD, of The Lodge, Shortlands, in the County of Kent,
DSc, Telegraph Engineer, do hereby declare the nature of this invention to be
as follows,
My invention relates to improvements in the construction and arrangement
of the various parts which constitute a submarine or like telegraph cable circuit,
and in the method and means of transmitting and receiving signals through the
same, whereby an increase of speed in working such circuits is obtained.
In carrying out this invention I employ in the sending circuit of the system and
in conjunction with a suitable automatic transmitter, preferably of one of the
forms described in Letters Patent No 5508 dated March 16th 1894 on No. 11069
dated June 7th 1894, a suitable induction coil joined up either as a shunt to the send-
ing condensers or in series with the sending condensers between the latter and
Faith The induction coil for the purpose of this invention is to be constructed
without iron or other magnetic material and to consist of a seues of coils whose
inductance is of suitable amount relatively to the capacity of the sending con-
dense18 When the induction coil is used as a shunt to the sending condensers
an adjustable non-inductive resistance is sometimes included in the condenser
circuit to assist in equalizing the time constant of the two circuits, namely, the
condense cucuit and the induction coil circuit, when the induction coil is placed
in series with the sending condensers the contact levers of the automatic trans-
mitter or signalling key are so connected up to the sending condensers as not to
short-circuit the induction coil after battery contacts
"
The object of combining the automatic curb transmitter with self-induction
coils in the sending cucuit of a cable system in the manner above described is
to provide a ready and sufficient means of regulating the amount of "cuib
required to produce the most rapid changes at the beginning of the cable and
thus to obtain the best results in speed and sharpness or clearness of signals.
In the receiving encuit I employ the usual siphon recording instrument some-
times having a receiving condenser in connection with it and with an adjustable
shunt consisting of a series of self-induction coils, without iron or other magnetic
material in their construction, whose inductance can be varied readily in relation
to the resistance of the receiving instrument and the capacity of the receiving
condenser employed. Or sometimes I prefer to use a suitable transformer insert-
ing the receiving instrument in one of its circuits and joining the other circuit up
between the cable and the earth, with or without a receiving condenser and shunted
in the manner above described.
For the purpose of thus invention I prefer to construct the shunt of a series of
flat coils whose mean diameter is 34 times their sectional width, the section being
10und or square, without iron.
In order to adapt this invention to the case of duplex-working I sometimes
construct the bridge or differential circuit of two self-induction coils formed ad-

page_text: justable in connection with the usual blocks of condensers and shunting the latter
for the purpose of duplex-balancing both in resistance and in inductance, or some-
times in series with the bridge condensers I insert adjustable non-inductive resist-
ances and place a self-induction coil either as a shunt to the automatie tians-
mutter cucuit or in series therewith The receiving instrument together with
the receiving condensei, shunted in the manner above descubed, may be placed
according to this invention either between the cable and the artificial cable as
Munheads so-called double-block system of duplex, or between the index of
the low resistance rheostat and caith, as in the so-called Harwood s plan of duplex-
working When Harwood s plan of connexions is adopted and an induction coil
hunt to the encuit of the automatic transmitter or signalling key is emploved
the contact levers of the transmitter or hey are so connected up between the cable
and artiheal cable as not to shortencuit the induction coil shunt after batter
contacts
In cases where there are intermediate cable stations between any two points
of a cable system I insert at the intermediate stations leakage circuits composed
of self-induction coils, similar leakages if necessary being placed at corresponding
points of the artificial cable
In order to facilitate the final duplex balancing of the artificial cable against
the cable in the above combinations I sometimes constinct the coils of the rheostat,
which is usually inserted between the transmitter and the block or bridge con-
den eis, in such manner as to have self-induction of an amount which can be
readily varied in order to counteract the effect on the duplex balance of that of
the real cable In the construction of this rheostat one half of the coils are wound
non-inductively and the other half in such manner as to have the amount of self-
induction equined to balance that of the real cable And sometimes I construct
the beginning or fist portion of artificial cable of alternate sections of self-induction
and capacity, the self-induction being closed solenoids with or without non, the
total being equal to that of the real cable Between the earth and the carth
terminals of the inductive resistances which compose the artificial cable are some-
times placed coils of wire inductively wound, of in some cases an electromagnet
whose resistance and inductance can be readily adjusted
1
•
T
1000
A. F SPOONER,
323, High Holborn, London,
Agent for the Applicant
Improvements relating to Electric Telegraphs.
I, ALEXANDER MURI AD, of The Lodge, Shortlands, in the County of Kent,
D Se, Telegraph Engineer, do hereby declare the nature of this invention and m
what manner the same is to be performed, to be particularly described and ascei-
tained in and by the following statement.-
My invention relates to submarine telegraphy and it consists principally in
providing such cable circuits with improved means, and certain combinations and
organizations of parts, for transmitting and receiving signals, and whereby an
increase of speed in working the said cncuits is obtained and other conveniences
and advantages secured.
In the accompanying drawings, which are diagrams, Figure 1 depicts a typical
way of carrying out my invention, and Figure 2 serves to show certain modifira-
tious attendant upon the transposition of the transmitting and receiving circuits

page_text: Both diagrams show connections for "duplex" working, Crepresenting the
cable and the artificial cable, though obviously my invention 18 applicable to
other cable cucuits.
T represents the transmitting instrument which may advantageously be an auto-
matic transmitter such as one of those patented to me by pio1 Letters Patent
No 5508 dated March 16th 1894 or No 11069 dated June 7th 1894, and it is so in-
dicated in the diagrams, but other forms of signalling keys or their equivalents
may be employ ed
As will be understood, B indicates the batteries, E the earth connections, and S¹,
S, Sindicate condensers
According to my invention I employ, in the sending cucuit, a self-inductance
coil L joined up in parallel with the key or transmitter T and its battery B The
said instrument L is constructed without non or other magnetic material and
it consists of a series of coils whose inductance is of suitable amount relatively to
the capacity of the sending condensers S¹, Sz The contact levers of the auto-
matic transmitter (or the signalling key) are so connected up to the sending
condensers as not to shont-cncuit the self-inductance coil after battery contacts
The object of so combining with the sending condensers S1, S2 and the key on
transmitter T, a self-inductance coil in the sending cucuit of the system is to
provide a ready and sufficient means of regulating, by reason of the extra cur-
ient in the self-inductance coil, the amount of curbequed to produce the
most rapid changes at the beginning of the cable and thus to obtain the best
esults in speed and sharpness on cleaness of signals
"
In the receiving cucuit of the system I employ by preference the usual siphon
recording instrument as indicated at R, but it may be any other suitable instru-
mentality, and there may be a receiving condenser S¹
According to my invention I employ in the receiving cncuit, .18
an adjustable shunt, an instrumentality, L', consisting of શ selles of
selt inductance coils, without 11011 01 other magnetic material 111 then
construction, whose inductance Can be varied readily in iclation to
the resistance of the receiving instrument and the capacity of the
eceiving condense employed. When the receiving instrument and receiving
condenser S are thus shunted by the self-inductance coil L' more sudden changes
are attained in the circuit of the recorder The main current flowing out of the
cable encounters only a simple resistance in the loop, that is both the self-induction
of the shunt and the capacity of the condensei are cancelled in the effect. All
the first impulses of the current flow through the recorder; the steady current
through the self-inductance coil L' The more rapid the variations of potential
at the sending end, the more of the resulting disturbance at the receiving end
takes place in the recorde cu cuit.
For the purpose of this invention I prefer to construct the last mentioned shunt
of a series of flat coils whose mean diameter is about three-and-a-quarter times
then sectional width, the section being round, on square, without non
As will be seen by comparison of the two diagrams the receiving instrument R
together with the receiving condenser S shunted in the manner described may be
placed either between the cable and the artificial cable Cas m Munhead's 50-
called double-block system of duplex and as shown in Figue 1, or between the
index of the low-resistance rheostat Rh (that is usually located at the apex of the
"budge') and earth as shown in Figure 2
In the latter case I divide the lust mentioned self-inductance coil into two
parts such as those indicated at L, L adjustable in connection with the usual
blocks of condensers and shunting the latter for the purpose of duplex balancing
both in resistance and in inductance
In order to facilitate the final duplex balancing of the artificial cable C¹ against
the cable C I construct the coils a of the 1heostat Rh in the same manner as the
hereinbefore mentioned self-inductance coils so as to have self-inductance of an

page_text: amount which can be readily vaned in order to counteract the effect on the duplex
balance of that of the real cable. To the same end I may extend the pinciple of
the self-inductance coils of the theostat Rh and insert adjustable self-inductance
coils of low-resistance between the sending condensers S¹, S and the cable and
artificial cable respectively as indicated at L³, L³ These coils facilitate the duplex
balancing by diminishing the rate of variation of potential due to the outgoing
current from the signalling battenes at the points where the cable and artificial
cable are joined to the receiving circuit thus producing less "jar" on the receiving
instrument
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1 In a duplex submarine telegraph cucut, the combination of a transmitter
and its battery, sending and receiving condensers, a heostat, a receivel.
self-inductances serving to regulate the amount of "cubrequined to pio-
duce the most rapid changes at the beginning of the cable, further self-inductance
Belving as a shunt to the said receiver and its condenser through which the steady
current passes whilst current impulses or rapid variations of potential operate such
receiver, and other self-inductances serving to facilitate the final duplex baluncing.
2 In a submarine telegraph circuit, the combination, with a transmitter and
the sending condensers, of a self-inductance coil joined up in parallel with the
transmitter and its battery, serving to regulate the amount of curb" requied
to produce the most rapid changes at the beginning of the cable substantially as
set forth.
"
In a submarine telegraph cucuit, the combination with a receiver and its
condenser, of a self-inductance coil serving as a shunt to the said receiver and
condenser through which the steady current passes whilst current impulses 01
rapid variations of potential operate the receiver substantially as set forth
4 In a duplex submarine telegraph circuit, self-inductances serving to facilitate
the final duplex balancing substantially as set forth.
5 A duplex submarine telegraph circuit having, in combination, a transmitter
and its battery, sending condensers, a self-inductance coil joined up in parallel
with the transmitter and its batteiv, a heostat, a receiver and its condenser, and
a self-inductance coil serving as a shunt to such receive and condensei
Dated in
Lu18 16 a
O
TONNA
A. F SPOONER,
323, High Holborn, London,
Agent for the Applicant
A. F SPOONER,
323, High Holborn, London,
Agent for the Applicant