IMPROVEMENTS IN TELEPHONIC APPARATUS
Year: 1879

page_text: LETTERS PATENT to Herbert John Haddan, of the Firm of Herbert and
Company, Solicitors of Patents, of 67, Strand, in the City of Westminster,
Civil Engineer, for the Invention of "IMPROVEMENTS IN TELEPHONIC
APPARATUS." A communication from abroad by George Black, of Hamilton,
Electrician, and Abner Mulholland Rosebrugh, of Toronto, Doctor of Medicine,
both in the Dominion of Canada,
PROVISIONAL SPECIFICATION left by the said Herbert John Haddan at
the Office of the Commissioners of Patents on the 16th April 1879.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. " IMPROVE-
MENTS IN TELEPHONIC APPARATUS." A communication from abroad by George
Black, of Hamilton, Electrician, and Abner Mulholland Rosebrugh, of Toronto,
Doctor of Medicine, both in the Dominion of Canada.
This Invention consists, first, in the combination with a telephone of the apparatus
commonly known as a "condenser,” the object of this part of the Invention being
to enable telephones or other secondary current apparatus to be connected with the
wire of any galvanic circuit without interfering with the action of said galvanic
circuit. The Invention consists, secondly, in connecting two or more wires of a
telegraph line running in the same direction and using them as conductor, by
which arrangement the resistance of the line is very much reduced; and the
advantageous result obtained, that the length of line on which a telephone can be
used, is very much increased. The Invention consists further in "grounding" the
wire of a telephone circuit at one, two, or more intermediate points, and in the
insertion in said ground wires of a "condenser" for the purpose of diminishing
the injurious effect of foreign induced currents. The Invention consists, lastly, in
connecting two or more independent galvanic circuits by means of a "condenser"
for the purpose of forming a telephonic circuit without interfering with the action
of said galvanic circuits. In using n "condenser" in connection with a galvanic
signal the condenser may be secured either behind the board to which the telephone

page_text: or signal apparatus is attached, or it may be secured behind a wall bracket used for
depositing letters, papers, etc., and hung near the telephone; and in using a second
condenser for the purpose of being able to ground the telephone at pleasure, the two
condensers may be placed adjacent to each other. When two or more independent
galvanic circuits are connected by means of a condenser for the purpose of forming
a telephone circuit without interfering with the action of said galvanic circuits, the
condenser may be for convenience secured to the upper part of a telegraph pole or
other supporting medium for the galvanic circuit lines. Instead of the "condenser'
as herein described, and as a substitute therefor, a medium offering high resistance
to a galvanic current, but comparatively no resistance to an induced current,
could be used in substantially the same manner and relation as the condenser.
"

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Herbert John Haddan in the Great Seal Patent Office on the 8th
October 1879.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. "IMPROVE
MENTS IN TELEPHONIC APPARATUS." A communication from abroad by George
Black, of Hamilton, Electrician, and Abner Mulholland Rosebrugh, of Toronto,
Doctor of Medicine, both in the Dominion of Canada.
This Invention relates more particularly to a method of using a condenser, or in
lieu thereof a resistance medium or its equivalent, so that a telephone and an
induced current signal apparatus may be connected with the wire of a galvanic
circuit without interrupting the action of said galvanic circuit, and it relates,
first, to a method of attaching two or more branch lines to a galvanic circuit, so
as to establish a telephone circuit; second, to a method of connecting two or more
parallel telegraph wires, and using them as a single conductor for a telephone line,
for the double purpose of reducing the resistance of the line and diminishing the
injurious effects of foreign induced currents, as well as to be able to use wires that
are also used for ordinary telegraph purposes; thirdly, in a method of connecting
two or more parallel telegraph wires, so as to establish an induced current circuit
without grounding; fourth, to a method of connecting two or more indepondent
galvanic circuits, so as to be able to utilize the wires of said galvanic circuits for
the construction of an induced current circuit; fifth, in a method of grounding a
telephone line at pleasure; sixth, in a method of interrupting a galvanic circuit for
the purpose of signalling without breaking the induced current circuit when
telephones are used on same line; and, seventh, in an automatic circuit closer so
arranged that when the telephones are not in use the galvanic circuit is kept
automatically closed.
Figure 1 is a line plan for branch line; Figure 2 is a line plan for parallel wires
used as a single conductor; Figure 3 is a line plan of parallel wires used without
grounding; Figure 4 is a line plan connecting two or more independent galvanic
circuits; Figures 5 and 6 are line plans for using condensers in divided lines of
galvanic circuits and for grounding; Figure 7, 7, is an automatic switch; Figures
8 and 9 represent a fluid resistance medium; Figure 10 represents a resistance
coil; Figures 11 and 12 represent a method of using a resistance medium and a
condenser in combination on the same branch line or derived liue; Figure 13 is a
modification of automatic switch.
In using two or more parallel telegraph wires as a conductor for a telephone or
secondary current circuit the resistance of the line is reduced, and the injurious effects
of foreign induced currents diminished without interfering with the working of said
telegraph lines. Foreign induced currents on these telegraph parallel wires will
flow in the same direction, and will meet and neutralize each other. A complete
circuit is thus formed for these foreign induced currents, and the telephones being
outside of this circuit, namely, between the condensers and the ground, the
injurious effects of these foreign induced currents on the telephone is either
neutralized or very much diminished. In Figure 2, 1 and 2 are parallel telegraph
wires; 1 is connected with the H pole of the telephone and signal by means of the
branch wire B, a condenser or resistance medium C being inserted between B and H;
2 is also connected to H thro' the condenser or resistance medium C¹. The opposite
pole of the telephone and signal H' is connected with the ground at E. Again, a
condenser or a resistance medium and a telephone with or without a secondary
current signal apparatus at the two ends of a telephone line may be inserted
between two parallel telegraph wires, and form a secondary current circuit without
grounding and without interfering with the action of the galvanic currents used on
said parallel telegraph wires. In Figure 3, 1 and 2 are connected with one pole of

page_text: the secondary. current apparatus including the telephone, and 3 and 4 wires are
attached to the other pole. In this case as well as in the one hereafter to be
described the telegraph wires may be used simultaneously for the transmission of
messages both by the galvanic circuit and by the induced current, and in using
parallel wires the injurious effects of foreign induced currents is diminished.
Figure 4 represents the method of connecting two or more independent galvanic
circuits for the purpose of forming a secondary current circuit without interfering
with the action of said galvanic circuits. 1, 1, 1, represent the first galvanic
circuit; 2, 2, 2, 2, the second; 3, 3, 3, the third galvanic circuit. A condenser C³
is connected by one pole to the first galvanic circuit, and by the other poles to the
second galvanic circuit, and a condenser 03 is connected in a similar manner to the
second and third galvanic circuits. B represents the branch line attached to the
first galvanic circuit at 1, and grounded at E and B' is a branch line attached to
the third galvanic circuit at 3 and grounded at E¹; C is a condenser; and D is
a telephone with or without other secondary current apparatus inserted in the one
branch line; and C₁ and D³ represent corresponding apparatus in the other branch
line. By means of the condensers C2, Cs, the wires 1, 1, 1, of the first, 2, 2, 2, 2, of
the second, and 3, 3, 3, of the third independent galvanic circuits can be utilized
to form a secondary current circuit between the branch lines B and B¹. Referring
to Figure 1 the method of using the condenser in connection with a telephone and
signal apparatus on branch lines may be described as follows:-At any point on a
wire 4 of a galvanic circuit a branch line B is attached and connected with the
ground in the usual way. In this branch line a condenser C, or in lieu thereof a
resistance medium and a telephone D, with or without an induced signal apparatus,
are inserted so as to form part of the circuit between the line 4 and the ground E.
When a single wire is used the condenser or resistance medium may be placed
either between the telephone and the line, or between the telephone and the ground,
but when two or more wires are used as a conductor the condensers or high resis-
tance coils or tubes are inserted in the branch lines between the telephone and the
main line, as shewn in Figure 2, at C, C'. One or more branch lines may be con-
nected at different points with the same galvanic circuit with corresponding
apparatus inserted therein so as to be able to form one or more telephone circuits
without interrupting the action of the galvanic current used on said galvanic
circuit. For convenience of reference and description the telephone and a secondary
current signal apparatus are represented as being combined in one instrument.
They may however be separate, and the condenser, resistance medium, or both
combined, may, if more convenient, be inserted between them.
When a condenser or condensers are used on a derived line of a galvanic circuit,
or in cases where a galvanic circuit is used for signal purposes on a telephone line,
the arrangement is as follows, reference being had to Figures 5 and 6-1, 11, is the
line; F, F¹, screw posts of telephone board; G, electro-magnet of call bell; and H‚Í³,
screw posts of telephone; C and C are the condensers secured behind the telephone
board;
and J is the call bell connected by wires K, K¹, to the line at F, F'. One
pole of the condenser C is connected with the line at F, and the other pole with the
screw post L, by which it is connected with the telephone at H. One pole of the
telephone at H is connected with the line at F¹, and the other pole passing through
the post L connects with one pole of the condenser C through the screw post L. By
means of the condenser C the secondary current circuit through the telephone
remains unbroken notwithstanding the interruption of the galvanic circuit through
the coil G during signalling. In order to ground the telephone at will at an inter-
mediate station without interfering with the galvanic circuit a second condenser C5
is added, one pole C of which is connected with the screw post F', and the other
pole C is connected with the contact point M. In using a condenser in connec-
tion with a galvanic signal the condenser may be secured either behind the board
to which the telephone or signal apparatus is attached, or it may be secured behind
a wall bracket used for depositing papers, letters, &c., and hung near the telephone;
and in using a second condenser for the purpose of being able to ground the

page_text: telephone at pleasure the two condensers may be placed together. If the message is
from the direction of F the switch is turned to the contact point N which connects
it and one pole of the condenser C with the ground wire through the bending
post L. The induced current will then pass from F¹ through the telephone to H, to
the binding post L, and then to the pole C of the condenser C, the opposite
pole C¹ being grounded through N. If the messages is from the direction F, the
switch P is turned to the contact point M. when the induced current will pass
from F to C, and from C to L, H, and through the telephone to F¹, and thence
to C of the second condenser, the opposite pole c being grounded through M.
The arrangement of the automatic circuit breaker is shewn in Figure 7. D is
the telephone; D₁, the telephone board; D, the mouth piece; and E, the circuit
breaker; E is a brass spring connected with the wire F, which is connected with
the ground wire H; E² is a brass spring connected with the wire F³, and between
the points E¹ and E2 a brass strip G is secured to the block to which the mouth-
piece D is attached. The telephone board is secured in an upright position,
preferably to a wall, and the weight of the mouth-piece causes the brass-bar G to
make contact with E1, E2, and close the galvanic circuit. A signal can be given by
elevating the mouth-piece, and when the mouth-piece is in position for speaking or
listening the electro-magnet is shunted. In Figure 13 another form of automatic
circuit closer is suggested at A. When the circuit is broken by drawing on the
cord B, the cord B may for convenience be attached to a foot treadle. The spring C
closes the circuit automatically. In cases where high resistance is used in a branch
line in connection with the secondary current signalling apparatus a condenser is
used as a cut out, or by means of a switch either may be put in circuit at pleasure,
as represented in Figure 11, B being branch line; C, condenser; R, resistance
medium; E¹, ground wire; and X, a switch. If the attention of an operator is to
be attracted by means of a magneto-electric machine with bell attachment a
resistance medium in the branch or derived lines is to be preferred, but if attention
is to be called by means of pulsatory currents in the telephone a condenser is to
be preferred. The condenser is also preferable for conversation, hence the advantage
of combining a resistance medium and a condenser in the same branch line or the
same derived line.
In Figures 8 & 9 A is a glass tube; B, metallic caps fitting it air tight and
connected with platinum points C, to which the wires D, D₁, are attached. This
tube is filled with water, preferably distilled, or glycerine and water, the proportions
thereof being regulated according to the size of the tube or desired strength of the
resistance, or such other liquid or liquids as may be found suitable for the purpose.
If the caliber of the tube is very small the water may be slightly acidulated before
sealing.
The
In Figure 10 a sectional view is shewn of a novel method of constructing a
resistance coil of German silver or other insulated wire incased in a suitable tube
made of a non-conducting material, which is so arranged that by a proper connection
of the terminal wires a resistance, say, of five hundred, one thousand, or two
thousands ohms, may be obtained according to the requirements of the case.
non-conducting bobbin is wound double and the terminals connected with
strong copper wire. The coil is coated with shellac and incased in a hard rubber
tube. If two wires A, B, C, D, have a resistance, say, of one thousand ohms each
by connecting B, D, there will be a resistance of two thousand ohms between A
and C; but when A and C are also connected and the double wires used as a
conductor the resistance goes down to five hundred ohms. The wires B and D
may for convenience be connected permanently and only one terminal used. The
resistance of each medium should be marked in ohms. The amount of resistance
must be regulated in each case according to the strength of the galvanic current
and the resistance of the galvanic circuit. It should be sufficiently high to ensure
perfect safety to the galvanic circuit and not too high to make the induced current
of the telephone too feeble for practical use.
The method of constructing the condenser is fully described in electrical works

page_text: and is well known to scientific men. Its construction may be briefly described as
follows: A condenser is made to expose a large surface to inductive action, and is
constructed of alternate layers of tin foil and thin plates of mica, gutta percha, or
paper saturated with parrafine arranged like the leaves of an inter-leaved book.
Each alternate metal plate is connected so as to form a distinct series, and each
series is insulated from the other and connected with separate binding posts.
I do not claim broadly using two parallel wires as a single conductor for the
purpose of diminishing the injurious effects of foreign induced currents on telephone
lines; I do not claim the construction of electric telegraphs for the simultaneous
transmission of current signals and wave signals on the same wire and separate
receiving instruments, the one sensitive to currents of appreciable duration and the
other to electric waves or vibrations; I do not claim the construction of electric
telegraphs with, at the transmitting station, an instrument capable of originating
in the line wire a succession of rapid and regular electric waves.
I claim as new and desire to secure by Letters Patent,―
1. In two or more branch lines of a galvanic circuit the combination of a
resistance medium, a telephone, and a ground wire, so as to form a telephone circuit
without interfering with the action of the galvanic current used on said galvanic
circuit.
2. In two or more branch lines of a galvanic circuit the combination of a
condenser, a telephone, and a ground wire, so as to form a telephone circuit without
interrupting the action of the galvanic current used on said galvanic circuit.
3. In two or more branch lines of a galvanic circuit the combination of a
condenser, a telephone, a secondary current signalling apparatus, and a ground
wire, substantially as and for the purpose specified.
4. In two or more branch lines of a galvanic circuit the combination of a
resistance medium, a telephone, a secondary current signalling apparatus, and a
ground wire, substantially as and for the purpose specified.
5. On one or more derived lines of a galvanic circuit the combination of &
resistance medium and a telephone, substantially as described.
6. On one or more derived lines of a galvanic circuit the combination of a
condenser and a telephone, substantially as described.
7. In connection with two or any number of parallel telegraph wires and at the
two ends of a telephone line the combination of two or more resistance mediums
for the purpose of forming a telephone conductor with the object of reducing the
resistance of the line, diminishing the injurious effects of foreign induced currents in
the telephones, and so as to be able to construct an induced current circuit on wires
used simultaneously for ordinary telegraph work without interrupting the action of
the galvanic currents used on said wires.
8. In connection with two or any number of parallel telegraph wires and at the
two ends of a telephone line and in connection with a ground wire the combination
of two or more condensers for the purpose of forming a telephone conductor with
the object of reducing the resistance of the line, diminishing the injurious effects of
foreign induced currents in the telephones, and so as to be able to construct an
induced current circuit on wires used simultaneously for ordinary telegraph work
without interrupting the action of the galvanic currents used on said wires.
9. In connection with two or any number of parallel telegraph wires and at each
end of a telephone line, and in connection with a ground wire, the combination of a
telephone, an induced current signal apparatus, and one or more resistance mediums
so as to be able to form an induced current circuit without grounding and without
interrupting the action of the galvanic currents used on said telegraph wires.
10. În connection with two or any number of parallel telegraph wires and at
each end of a telephone line the combination of a telephone, an induced current
signal apparatus, and one or more condensers, so as to be able to form an induced
current circuit without grounding and without interrupting the action of the
galvanic currents used on said telegraph wires.
11. The combination of a resistance medium or mediums, the wires of two or

page_text: more independent galvanic circuits, and two branch lines (each branch line with a
resistance medium) induced current signal apparatus, and a ground wire) for the
purpose of utilizing the wires of independent galvanic circuits with the object of
forming an induced current circuit without interfering with the action of said
independent galvanic circuits, substantially as specified.
12. The combination of a condenser or condensers, the wires of two or more
independent galvanic circuits, and two branch lines (each branch line with a
condenser, induced current signal apparatus, and a ground wire) for the purpose of
utilizing the wires of independent galvanic circuits with the object of forming an
induced current circuit without interfering with the action of said independent
galvanic circuits, substantially as specified.
13. At an intermediate station on a telegraph or telephone line and on a derived
line of the same the combination of two resistance mediums, a telephone, a shunting
switch, and a ground wire, so that the telephone may be grounded at pleasure
without interrupting the action of the galvanic circuit used on the line.
14. At an intermediate station on a telegraph or a telephone line and on a
derived line of the same the combination of two condensers, a telephone, a shunting
switch, and a ground wire, so that the telephone may be grounded at pleasure
without interrupting the action of the galvanic circuit used on the line.
15. At an intermediate station on a telegraph or a telephone line and on a
derived line of the same the combination of a condenser and a telephone, so as to
be able to interrupt the galvanic current during signalling without breaking the
secondary current.
16. At an intermediate station on a telegraph or a telephone line and on a
derived line of the same the combination of a resistance inedium and a telephone,
so as to be able to interrupt the galvanic current during signalling without breaking
the secondary current.
In witness whereof, I, the said Herbert John Haddan, have hereunto set my
hand and seal, this Seventh day of October, A.D. 1879.