IMPROVEMENTS IN ELECTRIC TELEGRAPHS."
Year: 1874

page_text: In the Matter of a Patent granted to JOHN MUIRHEAD, junior,
of Stanley Villa, Thornton Hill, Wimbledon, in the County of
Surrey, for the Invention of "IMPROVEMENTS IN ELECTRIC
TELEGRAPHS." bearing date the 23rd day of October 1874 +

page_text: "accumulator or condenser is so proportioned as to make its resistance
" to the passage of a current the same as that of a given length of the
"real cable, whilst its surface is of such dimensions that (with the
"insulating material employed) its capacity to retain a charge may also
" be the same as that of the same length of actual cable.
$$
"It is obvious that two or more of these accumulators or condensers
may be coupled in continuous circuit, so as to obtain their combined
"effects in augmenting both resistance and capacity. Or they may be
coupled side by side, or in multiple circuit, so as to obtain their com-
"bined effects in augmenting capacity, whilst the resistance is decreased
"in the ratio of the number employed."
"
And I also strike out the paragraph com
menoing with tho words "The accumulators," in line 81 of page 5 of the said printed copy, and ending with the words "the
terminals," in line 33 of the same page,
J
And in order that the effect of this Disclaimer and Memorandum of
Alteration may be better understood, I annex a copy of the Specification
as it will appear when such Disclaimer and Memorandum of Alterations
has been made as aforesaid.
" TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
"MUIRHEAD, junior, of Stanley Villa, Thornton Hill, Wimbledon, in.
"the County of Surrey, send greeting.
66
66
66
"WHEREAS Her most Excellent Majesty Queen Victoria, by Her.
"Letters Patent, bearing date the Twenty-third day of October, in.
"the year of our Lord One thousand eight hundred and seventy-four, in
"the thirty-eighth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said John Muirhead, Her
"special license, that I, the said John Muirhead, my executors, ad-
ministrators, and assigns, or such other's as I, the said John Muirhead,
my executors, administrators, and assigns, should at any time agree
"with, and no others, from time to time and at all times thereafter.
"during therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain
"and Ireland, the Channel Islands, and Isle of Man, an Invention
" for "IMPROVEMENTS IN ELECTRIC TELEGRAPHS," upon the condition (amongst
others) that I, the said Jolin Muirhead, my executors or administra-
tors, by an instrument in writing under my, or their, or one of their
"hands and seals, should particularly describe and ascertain the nature
" of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Office
"
66
66
the term
A
'

page_text: "within six calendar months next and immediately after the date of
"the said Letters Patent.
"NOW KNOW YE, that I, the said John Muirhead, do hereby declare
"the nature of the said Invention, and in what manner the same is
" to be performed, to be particularly described and ascertained-in and
by the following statement thereof, that is to say :-
"
:-
"This Invention has for its object improvements in electric tele-
"graplis.
"
"In order to increase the sensibility of recording instruments by
diminishing the resistance to motion of the recording part or marker
"I employ as the marker a short piece of capillary tubing, rising
* directly from an ink cup. In instruments, such as the Morse ink
writer, I attach to one end of the armature lever an upright capillary
tube, which tube I sometimes make taper, larger at the lower end
than at the upper.
"
tr
"The ink rises to the upper end of the tube, and marks on a travelling
strip of paper. The marking tube is connected with the indicator of
the instrument, which raises it from time to time into contact with
"the travelling strip, so as to record dot and dash signals.
66
Figure 1 shows the vertical capillary marker attached to the arma-
"ture lever of an ordinary Morse ink writer. A is the marker; B, the
" armature lever; and C, the ink box. In those instruments, in which
"the indicator moves laterally, connection is made so as to convey to
"the marking tube such lateral movement, whilst the ink exuding from
its upper end traces a continuous line upon the travelling strip. A 1
"sensitive form of receiving instrument or indicator for this purpose
"consists of a polarized electro-magnet with semi-circular head pieces
"of soft iron, above which is suspended bifilarly a light piece of iron
"wire, but round at each end, and having attached to one end a
light aluminium rod carrying the vertical capillary marker, as above
" described.
"
"
Figure 2 shows a diagram of this arrangement. N, N, and S, S,
are the head pieces of the electro-magnet, and a is the light iron wire
suspended over it; a³, a¹, are its curved ends; and a², the arm con-
"nected with the marker.
"
"Another sensitive form of instrument I employ consists of a
moveable conductor conveying the line current, and constructed of a

page_text: "double coil or two coils joined up in proper order, so as to form
"
a figure 8. This indicator is suspended bifilarly, or pivotted between
"the poles of a powerful magnet either electro or permanent, and the
" compound coil turns about the middle point.
"The vertical marker above described is attached to the suspended
" coils by means of a light aluminium lever.
" Figures 3 show the arrangement of double coils suspended by two
"threads from a bracket above, and by one thread fixed below. A is
" the marker; B is the light aluminium lever; C, the ink box; D, the
"suspended coils; E, the magnets.
"Sometimes in place of marking by means of ink I employ a
"chemically prepared paper and a metal capillary tube dipping into a
"solution of caustic potash. By passing a current from a battery
through the paper the resistance to motion of the point of the tube on
"the paper is diminished. The current from the battery also assists the
"flow of liquid through the tube.
**
"Also in chemical recording instruments I employ hollow metal
"styles, through which a liquid is made to flow on to the travelling
"strip of chemically prepared paper, rendering it more sensitive to
"weak currents.
"Another part of my Invention has for its object to construct an
"accumulator or condenser in which the power of conduction is
adjusted. Such an accumulator or condenser can be constructed
"combining both the conduction and capacity resistance required to
"imitate exactly a real line.
"My accumulators or condensers are specially adapted for use in
duplex working systems, I proceed as follows:-I take two strips of
"tin foil (or other thin metallic sheet) and lay them one over the other,
"separated by an insulating material.………………………… One strip of metal
"is connected at each end with the connecting clamps of the instru-
"ment, and is arranged in one continuous line to the length required,
"
so that the resistance of the entire length of thin metal comes into
"play. The conducting sheets are made of proper dimensions to give
"the desired resistance and amount of surface. The two sheets
"with the non-conductor between them are folded into a convenient
shape.

page_text: The way in which I use this instrument in duplex telegraphy is as
"follows:-
-
"The current established by each contact made by the sig-
nalling key is caused to divide into two parts; one part is passed
through the actual cable and affects the indicator at. the receiving end, t
"and the other part is caused to pass through the accumulator or
"condenser by the continuous strip of thin metal attached as before
"mentioned to the connecting clamps, and so this portion of the
" current passes to earth. The other strip (or strips) of thin metal has
"also an earth connection or connections.
"The signalling currents passing into the cable and into the accu-
"mulator or condenser, which is made to imitate the cable, neutralize
"each other as to their effect on the indicator at the transmitting
" station.
1
"The resistance of the thin metal used in the accumulator or con- 1
"denser is ascertained by experiment, and the conducting sheet of the
" accumulator or condenser is so proportioned as to make its resistance
" to the passage of a current the same as that of a given length of the
"real cable, whilst its surface is of such dimensions that (with the
"insulating material employed) its capacity to retain a charge may also 2
" be the same as that of the same length of actual cable.
"
"It is obvious that two or more of these accumulators or condensers
may be coupled in continuous circuit so as to obtain their combined
"effects in augmenting both resistance and capacity. Or they may be
coupled side by side or in multiple circuit so as to obtain their com- 2
"bined effects in augmenting capacity, whilst the resistance is decreased
" in the ratio of the number employed.
"
"
$
Having thus described the nature of my said Invention and the
manner of performing the same, I would have it understood that I
"claim as my improvements in electric telegraphs,―
"First. The capillary marker, consisting of a tube dipping at its.
"lower end into an ink vessel, and at its upper end being brought into
" contact with and made to mark a travelling surface, either continuously
"or intermittently, substantially as described.
"
8
" Second. The apparatus combined with the said capillary marker for a
actuating it, substantially as described.

page_text: C
Third. The arrangement of the figure-of-eight coil and magnet for
use as a receiving instrument, substantially as described.
"Fourth. The use in telegraph receiving instruments of a hollow
style, through which a battery current is passed, and through which
a liquid is supplied, substantially as described.
"Fifth. The method of constructing accumulators or condensers
with the thin metal arranged in a continuous line, so that a resistance
is obtained corresponding with the length of metal employed, sub-
stantially as described."
In witness whereof, I, the said John Muirhead, have hereunto set
my hand and seal, this Sixth day of May, in the year of our Lord
One thousand eight hundred and seventy-five.
I hereby grant my fiat, giving leave to the above-named John Muir-
head, junior, to file in the Great Seal Patent Office, with the Specification
to which the same relates, the above written Disclaimer and Memo-
randum of Alteration, dated this Thirty-first day of May, One thousand
eight hundred and seventy-five.

page_text: LETTERS PATENT to John Muirhead, junior, of Stanley Villa, Thornton
Hill, Wimbledon, in the County of Surrey, for the Invention of
"
PROVISIONAL SPECIFICATION left by the said John Muirhead at the
Office of the Commissioners of Patents, with his Petition, on the
23rd October 1874.
I, JOHN MUIRHEAD, junior, of Stanley Villa, Thornton Hill,
Wimbledon, in the County of Surrey, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN ELECTRIC TELEGRAPHS," to be as
follows:-
This Invention has for its object improvements in electric telegraphs.
In order to increase the sensibility of recording instruments by
diminishing the resistance to motion of the recording part or marker, I
employ as the marker an upright capillary tube. dipping at its lower end

page_text: into an ink cup. The bore of the tube I make taper, larger at the lower
end than at the upper. The ink rises to the upper end of the tube and
marks on a travelling strip of paper. The marking tube is connected
with the indicator of the instrument which raises it from time to time
into contact with the travelling strip so as to record dot and dash
signals. Or the connection with the indicator may be such as to convey
to the marking tube a lateral movement, whilst the ink exuding from
its upper end traces a continuous line upon the travelling strip.
A sensitive form of receiving instrument or indicator for this purpose
consists of an electro-magnet with semicircular head pieces, above which
a light piece of iron wire is suspended having attached to one end the
vertical capillary marker as above described. Or to obtain a great
concentration of magnetic force I employ as an indicator a movable
conductor conveying the line current, and constructed of a double coil
or two coils joined up in proper order so as to form a figure 8. This
indicator is suspended or pivotted between the poles of a powerful
magnet, either electro or permanent, and the coil turns about middle
point.
Or
Sometimes I employ chemically prepared paper, and in place of
marking upon it with.a metal style connected with a battery, as is well
understood, I employ a capillary tube charged with a liquid through which
the battery current employed to act upon the prepared paper passes.
when not employing chemically prepared paper I sometimes apply a
battery in the manner stated to assist the flow of ink through the
capillary marking tube.
I construct a sensitive receiving instrument indicating by sound by
placing back to back two sheets of silvered paper stretched on a frame,
one connected with the line and the other to earth.
'
The signals are indicated by a noise made each time the silvered
paper is discharged..
A small mirror may be attached to one of the sheets and a beam of
light thrown upon it in order to render visible a slight motion which
accompanies the sound, so that the signals may also be read by the eye.
Or the line may be connected with a primary coil, the sounder being
connected with a secondary. The sounder may be replaced by a bar of
iron within a coil, which by a rapid succession of reverse currents can
be caused to emit a sound..

page_text: I construct an accumulator or condenser specially adapted for use in
duplex working systems by winding strips of tinfoil (or other thin
metallic sheet) separated by an insulating material in one continuous
length. The conducting sheet is made of proper dimensions to give the
resistance per unit of length required, and the insulating material is
adjusted to have a specific inductive capacity corresponding to that of the
line. Such an accumulator can be constructed combining both the
conduction capacity and resistance required to imitate a real line. The
inductive capacity of the insulating compound can be varied within
limits by varying the per-centage amount of the ingredients.
[ SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Muirhead in the Great Seal Patent Office
on the 23rd April 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MUIRHEAD, junior, of Stanley Villa, Thornton Hill, Wimbledon, in the
County of Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of October, in the year of our
Lord One thousand eight hundred and seventy-four, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Muirhead, Her special license,
that I, the said John Muirhead, my executors, administrators, and
assigns, or such others as I, the said John Muirhead, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
ELECTRIC TELEGRAPHS," upon the condition (amongst others) that I, the
said John Muirhead, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said John Muirhead, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
This Invention has for its object improvements in electric telegraphs.
.
In order to increase the sensibility of recording instruments by
diminishing the resistance to motion of the recording part or marker, I
employ as the marker a short piece of capillary tubing rising directly
from an ink cup. In instruments such as the Morse ink writer I attach
to one end of the armature lever an upright capillary tube, which tube
I sometimes make taper larger at the lower end than at the upper. The
ink rises to the upper end of the tube and marks on a travelling strip of
paper. The marking tube is connected with the indicator of the
instrument which raises it from time to time into contact with the
travelling strip so as to record dot and dash signals.
Figure 1 shows the vertical capillary marker attached to the armature
lever of an ordinary Morse ink writer. A is the marker; B, the
armature lever; and C, the ink box. In those instruments in which the
indicator moves laterally connection is made so as to convey to the
marking tube such lateral movement, whilst the ink exuding from its
upper end traces a continuous line upon the travelling strip.
A sensitive form of receiving instrument or indicator for this purpose
consists of a polarized electro-magnet with semicircular head pieces of
soft iron, above which is suspended bifilarly a light piece of iron wire
bent round at each end, and having attached to one end a light a
aluminium rod carrying the vertical capillary marker as above
described.
Figure 2 shows a diagram of this arrangement. N, N, and S, S, are
the head pieces of the electro-magnet, and a is the light iron wire
suspended over it; a¹, a¹, are its curved ends, and a² the arm connected a
with the marker.
Another sensitive form of instrument I employ consists of a moveable
conductor conveying the line current, and constructed of a double coil
or two coils joined up in proper order so as to form a figure 8. This
indicator is suspended bifilarly or pivotted between the poles of a 3
powerful magnet, either electro or permanent, and the compound coil

page_text: turns about the middle point. The vertical marker above described is
attached to the suspended coils by means of a light aluminium lever.
•
Figures 3 shew the arrangement of double coils suspended by two
threads from a bracket above and by one thread fixed below. A is the
marker; B is a light aluminium lever; C, the ink box; D, the
suspended coils; E, the magnets.
Sometimes in place of marking by means of ink I employ a chemically
prepared paper and a metal capillary tube dipping into a solution of
caustic potash. By passing a current from a battery through the paper
the resistance to motion of the points of the tube on the paper is
diminished, the current from the battery also assists the flow of liquid
through the tube. Also in chemical recording instruments I employ
hollow metal styles through which a liquid is made to flow on to the
travelling strip of chemically prepared paper, rendering it more sensitive
to weak currents.
Another part of my Invention has for its object to construct an
accumulator or condensor in which the power of conduction is adjusted.
Such an accumulator or condensor can be constructed combining both
the conduction and capacity resistance required to imitate exactly a real
line.
My accumulators or condensors are specially adapted for use in duplex
working systems; I proceed as follows :-)
-I take two strips of tinfoil (or
other thin metallic sheet) and lay them one over the other separated by
an insulating material. Each strip of metal is connected at one end
with one of the connecting clamps of the instrument, and is arranged in
one continuous line to the length required, so that the resistance of the
entire length of thin metal comes into play. The conducting sheets are
made of proper dimensions to give the desired resistance and amount of
surface. The two sheets with the non-conductor between them are
folded into a convenient shape.
The accumulators or condensors now in use give but comparatively
small resistance, the numerous metallic sheets employed being separately
connected with the terminals.
Having thus described the nature of my said Invention and the
manner of performing the same, I would have it understood that I claim
as my improvements in electric telegraphs,-
First. The capillary marker consisting of a tube dipping at its lower

page_text: end into an ink vessel, and at its upper end being brought into contact
with and made to mark a travelling surface, either continuously or
intermittently, substantially as described.
Second. In apparatus combined with the said capillary marker for
actuating it, substantially as described.
Third. The arrangement of the figure of eight coil and magnet for
use as a receiving instrument, substantially as described.
Fourth. The use in telegraph receiving instruments of a hollow style
through which a battery current is passed, and through which a liquid is
supplied, substantially as described:
Fifth. The method of constructing accumulators or condensors with
the thin metal arranged in a continuous line, so that a resistance is
obtained corresponding with the length of metal employed, substantially
as described.
E
1
In witness whereof, I, the said John Muirhead, have hereunto 1
set my hand and seal, this Twenty-third day of April, in the
year of our Lord One thousand eight hundred and seventy-
five.