IMPROVEMENTS IN ELECTRIC TELEGRAPHS
Year: 1866

page_text: LETTERS PATENT to Josiah Latimer Clark, of 5, Westminster Chambers,
Victoria Street, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN ELECTRIC TELEGRAPHS."
Sealed the 14th May 1867, and dated the 19th November 1866.
PROVISIONAL SPECIFICATION left by the said Josiah Latimer Clark at
the Office of the Commissioners of Patents, with his Petition, on the
19th November 1866.
I, JOSIAH LATIMER CLARK, of 5, Westminster Chambers, Victoria Street,
in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN ELECTRIC TELEGRAPHS," to be as follows:-
My first improvement consists in the construction of the iron posts or
standards used for supporting telegraphs. The standard is made of wrought
or cast iron of the usual form, and to steady the base in the ground I attach
to it one or more earth plates, each formed of two similar pieces of cast iron
bolted together around the standard, and forming two wings which may be
placed in any direction best suited to resist the strain. Projections are
formed on these wings at two opposite sides of the pole, and two light iron-
rods attached to the bottom of the pole- pass over these projections and are
led to the top of the pole, the rods being furnished with a means for tightening
them and at the same time strutting them to the standard at different points
[Price 8d.]

page_text: by means of right and left handed screws or twisted wires with struts attached
to them and to the body of the pole.
My second improvement consists in rolling the iron poles with two or more
flanges or longitudinal wings on opposite sides of the pole so as to give greater
strength and stiffness to the pole in the direction of these flanges, than in any
other direction, or the same object may be attained by making the poles
thicker on two. sides than the other sides and by giving it an oval section. I
prefer to make these stiffened poles by rolling two plates of iron upon a
mandril, the edges of the plates forming the two longitudinal ribs or flanges,
and they may be either of the same diameter throughout or tapered from top
to bottom. The iron should be thicker at one end than the other so as to
make the bottom of the pole the strongest. The plates are welded together at
their edges by passing them through a pair of rollers with a gradually enlarging
pair of grooves upon their surfaces, their circumference being equal to the
length of the pole required; the two plates at welding heat, with a mandril
between, slide on rollers into the grip of the wheels, which at one revolution
complete the whole length of the pole, or the plates may be rolled separately.
into form and the two halves passed together through the welding rollers with
or without a mandril. The plates are made thicker at one end than the
other by rolling them through ordinary rollers with the compression screws at
each end so regulated as to open or close the rollers gradually as the plates
pass through them; their motion being alternately reversed.
My third improvement consists in forming the body of the pole of wrought-
iron plates riveted together, and the top length which carries the arms and
insulators of a solid wrought-iron tube either cylindrical or tapered, by which
combination a maximum of strength with a minimum of weight is obtained.
My fourth improvement consists in the application to telegraph poles or
standards, whether of wood or iron, of a thick coating of asphalt or pitch, or of
a mixture of this substance with silica, chalk, or earthy powder, the mixture
being supported round the pole by a coarse fibrous felt. canvas, or cloth, which
retains it in position; this fibrous coat of asphalte in a hot condition may
be either applied in one sheet or wound spirally around the pole.
It may
be attached by nails driven into the timber, or if the poles be of iron by rivets.
While still hot fresh asphalte should be applied and the whole smoothed by a
hot iron.
My fifth improvement relates to the construction of the supports for the
insulators. I make the bracket or support of the insulators of a combination
of wrought iron with cast iron, or steel with cast iron. The base of the

page_text: bracket is of cast iron of the usual form; this may either be in two pieces
entirely encircling the pole and carrying either one or more insulators, or it
may be single and attached to the pole in the ordinary manner by screws or
nails. The arm or support which bears the insulator is either of iron or steel, .
and is cast into this base piece, the iron being moulded or cast upon it while
in a melted state; the other extremity of the arm is fitted to receive the
insulator.
į
;
My sixth improvement consists in the attachment of the insulators to the
supports, which is effected by means of a socket piece, either plain or screwed,
which is cemented into the interior of the insulator; this socket piece may be
of metal, vulcanite, or other suitable material, or of cloth or other fibrous
material saturated with glue or other adhesive matter. but I prefer to con-
struct the socket piece of lead or zinc. In fixing it into the insulator I first
fasten it or form it upon a screwed bolt or mandril, cement it into the insulator,
and afterwards withdraw the mandril, which may be used over and over again,
for forming or fixing fresh socket pieces. These socket pieces are applicable
either to the upright supports of insulators similar to those for which Letters
Patent were granted to the Inventor on the 29th Nov. 1856, (No. 2831), or
for those in which the wire is suspended beneath the insulator. When the
material of the insulator is one not likely to crack or be injured by the heat
the socket may be formed of melted metal within the insulator itself, the
mandril being afterwards withdrawn.
My seventh improvement is in the means of attaching the wire to the
insulator. When the insulator has a cast-iron bell or top I pass the iron over
the top between three snugs; two of these snugs are hooked or undercut .so as
to fit the wire; the third which is on the opposite side of the wire is furnished
with a screw or wedge which jams the wire into the two opposite hooks or
snugs, or one snug only may be used, the wedge or screw jamming the wire
downwards into a recess formed at the top of the iron cap for that purpose.
My eighth improvement consists in the use of lightning conductors com-
bined with an insulator, so that every insulator has its lightning protector.
These lightning conductors are attached either to the pole or to the arm, and
are kept in electrical connection with the earth; they are formed of iron
rods pointed at their extremities, and approach sufficiently near to the wire to
draw off the lightning electricity and prevent its bursting through the insulator.
The same end may be attained by attaching the pointed conductor to the wire
or the iron cap of the insulator and approximating the point of it to the pole
or neighbouring arm.

page_text: My ninth improvement relates to the instruments employed in signalling
hrough long submarine cables. In order to make the short sudden discharges
equisite for signalling through long cables I place the line in electrical con-
ection with a hard metal ball or hammer head fixed on an axis and furnished
ith a convenient handle. When the handle is moved to the right or to the
eft it strikes against one of two metallic checks, the one on the right connected
ith one pole of the battery, and the one on the left with the other pole, so that
ositive or negative currents can be sent into the line at pleasure.
The
ammer is attached to the handle by a spring with a stop on each side, 'which
ermits it to strike a momentary blow against the checks, but does not allow
to remain in permanent. contact with them. This system of momentary
ontacts by the ball may also be applied to the ordinary horizontal finger key.
or the receiving instrument I prefer to employ a light magnetised needle
uspended vertically either on an axis or a fibre; this needle is retained in its
ertical position by the attraction of the two poles of a larger magnet suitably
S
DN
placed for that purpose. Two nose pieces of soft iron S, S',
approach the upper end of the needle, one on either side of
it, and two other pieces N, N', similarly approach its lower
end. A permanent horse-shoe magnet unites the nose
pieces N and S on one side of the needle, and another similar
magnet units N¹ with S¹. The needle has its south pole
uppermost, which is consequently repelled by the two nose
pieces S, S', and its north pole downwards, which is similarly
epelled by the two lower nose pieces N, N'; it there remains in stable
quilibrium between them.. The nose pieces S and S¹, are also in connection
ith an electro-magnet wound with fine wire and placed in circuit with the
ne, and another similar magnet connects the nose pieces N and N¹, which is
Iso in circuit with the line, and is so arranged as to cause the needle to deflect
the right or left whenever traversed by a current. The signals may be read
irect from the needle, or the needle may be formed of polished steel ground
the form of a plane or concave mirror and reflecting an image on to a
creen in the usual manner, in which case the whole apparatus is best placed
orizontally.
My tenth improvement is an arrangement to obviate the inconvenience
aused by the wandering of the spot of light in working submarine cables too
uch to one side or the other of the scale, which is caused by earth currents
ending to deflect the needle continually to the right or left. I connect the
end of the cable to the earth, not directly but through a rheostal so arranged

page_text: that one end of the rheostal is connected to earth and the other end with a
battery which causes a current to flow continually through the rheostal. The
wire leading from the end of the cable presses upon the rheostal at some
point between the battery and the earth, and by revolving the rheostal some
point upon it will be found at which the tension exactly equals and neutralises
that of the cable. In order to mark the mean zero point upon the indicating
scale I use two coils and two mirrors both in connection with the cable; one
is of the ordinary construction, the other has its motions controlled and
rendered slow by a thin plate of talc moving in the air. Both pencils of light
follow each other from side to side upon the screen, one marking the signals
received and the other serving as a steady zero point from which the motions
of the lighter needle take their departure to the right and left.
by the said Josiah Latimer Clark in the Great Seal Patent Office on the
18th May 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME,
I, JOSIAH
LATIMER CLARK, of 5, Westminster Chambers, Victoria Street, in the County
of Middlesex. send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of November, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her 'rèign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said Josiah Latimer Clark, Her special licence that I, the said Josiah
Latimer Clark, my executors. administrators, and assigns, or such others
as I, the said Josiah Latimer Clark, 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 TELEGRAPES," upon the condition (amongst others)
that I, the said Josiah Latimer Clark, 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 caiise the same

page_text: to be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Josiah Latimer Clark, 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:--
My first improvement consists in the construction of the iron posts or
standards used for supporting telegraphs. The standard is made of wrought
or cast iron of the usual form, and to steady the base in the ground I attach
to it one or more earth plates, each formed of two similar pieces of cast iron
bolted together around the standard, and forming two wings which may be
placed in any direction best suited to resist the strain, projections are formed
on these wings at two opposite sides of the pole, and two light iron rods
attached to the bottom of the pole pass over these projections, and are led to
the top of the pole, the rods being furnished with a means for tightening
them and at the same time strutting them to the standard at different points
by means of right and left handed screws or twisted wires with struts attached
to them and to the body of the pole.
Figures 1 and 2 shew two opposite side views of an iron post or standard
suitable for supporting telegraph wires, and constructed in the manner above
described. The post shown in the Drawing is a wrought-iron post, formed
as will be presently described with its greatest diameter at a short distance
above the lower end of the post; the post may, however, if preferred, be
divided at its greatest diameter, as shewn at Figures 3 and 4, in this case I
prefer to connect the two parts together by .a pin passing into the adjoining
ends of the two tubes, as shewn in these Figures, and to hold the two parts
together by bolting them up with cast or wrought iron feet or earth plates,
which are to steady the poles in the earth.
In these Figures a are the poles which are rolled with ribs as herein-after
described; b, b, are two cast or wrought iron earth plates, one near the lower
end, of the pole, and the other a short distance above it so as to be a short
distance below the surface of the earth, as shewn; c, c, are twisted wires fixed
at their lower ends to the lower foot or steadying piece b, led over the outer
ends of arms b¹ of the upper steadying piece b, and fixed at their upper ends
to a ring d affixed to the pole near its upper end; the wires are twisted up to
tighten them by turning the struts e; the struts are then fixed to the poles and
the wires are thus held tight. Each of the earth plates b is formed in two
halyes, which between them encircle the post and are caused to clip it by

page_text: bolts, as shewn at Figures 5 and 6, which shew respectively plan views and
sections on a larger scale of the lower and upper earth plates; the views
shewn at Figures 6 of the upper earth plate also shewn clearly the manner of
carrying the arms or projections b' above mentioned.
2007 1
My second improvement consists in rolling the iron poles with two or
more flanges or longitudinal wings on opposite sides of the pole, so as to give
greater strength and stiffness to the pole in the direction of these flanges
than in any other direction, or the same object may be attained by making
the poles thicker on two sides than the other side, and by giving it an oval
section. I prefer to make these stiffened poles by rolling two plates of iron
to the shape required for forming one-half of the pole, the edges of the plates
forming the two longitudinal ribs or flanges, and they may be either of the
same diameter throughout or tapered from top to bottom. The iron should
be thicker at one end than the other so as to make the bottom of the pole the
strongest. The plates are welded together at their edges by passing them
through a pair of rollers with a gradually enlarging pair of grooves upon
their surfaces, their circumference being equal to the length of the pole
required, the two plates at welding heat with or without a mandril between
slide on rollers into the grip of the wheels, which at one revolution complete
the whole length of the pole, or the plates may be rolled separately into form
and the two halves passed together through the welding rollers with or without
a mandril. The plates are made thicker at one end than the other by rolling
them through ordinary rollers with the compression screws at each end so
regulated as to open or close the rollers gradually as the plates pass through
them, this motion being alternately reversed.
Figures and 8 shew two opposite side views of a telegraph post with solid
flanges on two opposite sides, as above described.
Figures 9, 10, and 1 shew a front view and sections of a pair of rolls
suitable for shaping the two longitudinal halves or parts of such a
pole, and
also for welding together the flanges of the two halves so as to form a pole
with longitudinal wings on its two opposite sides. The pole shewn in
Figures 7 and 8 is similar to the poles shewn in Figures 1 and 2; these poles
are made, as 1 now prefer, with their greatest diameter at a point a short
distance above the lower end of the pole, and to taper from this point towards
the two ends of the pole, as shewn.
To form a pole such as shewn in the Drawings two strips of metal each
suitable for forming one longitudinal half of the pole are first passed through
the grooves a of the rollers shewn at Figure 9, the two halves are then brought
:

page_text: to a welding heat and are together passed through the grooves b of the rollers,
by which the flanges or edges of the two halves are welded together; or to
weld the flanges of the two parts together the plates may be drawn together
through rollers or through draw tongs, or other arrangements may be adopted
for producing a pole with solid or welded flanges projecting from it, as above
described.
My third improvements consists in forming the body of the pole of wrought-
iron plates rivetted together, and the top length which carries the arms and
insulators of a solid wrought-iron tube, either cylindrical or tapered, by
which combination a maximum of strength with a minimum of weight is
obtained.
My fourth improvement consists in the application to telegraph poles or
standards, whether of wood or iron, of a thick coating of asphalt, or pitch, or of
a mixture of this substance with silica, chalk, or earthy powder, the mixture
being supported round the pole by a coarse fibrous felt, canvas, or cloth,
which retains it in position; this fibrous coat of asphalt in a hot condition may
be either applied in one sheet or wound spirally around the pole. It may be
attached by nails driven into the timber, or if the poles be of iron by rivets,
while still hot fresh asphalt should be applied, and the whole smoothed by a
hot iron; or cords or strings of fibrous material may be wound around the
posts and the asphalt be afterwards applied. The peculiarity of this part of
the Invention consists in the supporting the asphalte upon the pole by fibrous
materials.
My fifth improvement relates to the construction of the supports for the
insulators. I make the bracket or support of the insulators of a combination
of wrought iron with cast iron, or steel with cast iron. The base of the
bracket is of cast iron of the usual form; this may either be in two pieces
entirely encircling the pole and carrying either one or more insulators, or it
may be single and attached to the pole in the ordinary manner by screws or
nails; the arm or support which bears the insulator is either of iron or steel,
and is cast into this base piece, the iron being moulded or cast upon it while
in a melted state; the other extremity of the arm is fitted to receive the
insulator, or in place of this the base piece may be cast separately and the
arm be afterwards fixed into it by rivetting, as shewn at Figure 12.
My sixth improvement consists in the attachment of the insulators to the
supports, which is effected by means of a screwed socket piece, which is
cemented into the interior of the insulator; this socket piece may be of metal,
vulcanite, or other suitable material, or of cloth or other fibrous material,

page_text: saturated with glue or other adhesive matter, but I prefer to construct the
socket piece of lead or copper; in fixing it into the insulator I first fasten it
or form it upon a screwed bolt or mandril, then cement it into the insulator,
and afterwards withdraw the mandril, which may be used over and over again
for forming or fixing fresh socket pieces; these socket pieces are applicable
either to the upright supports of insulators similar to those for which Letters
Patent were granted to the Inventor on the 29th November 1856, (No. 2831,)
or for those in which the wire is suspended beneath the insulator. When the
material of the insulator is one not likely to crack or be injured by the heat
the socket may be formed of melted metal within the insulator itself, the
mandril being afterwards withdrawn. At Figures 13, 14, and 15 are shewn
examples of insulators, having cemented within them socket pieces, by which
the insulators are attached to the stems or supports which are to carry them;
the socket pieces are for this purpose formed with an internal screw thread to
screw on to an external thread on the end of the stem or support. In the
Drawings the stems are marked a, and the socket pieces b; the stem of any
insulator, such as shewn at Figure 13, may be affixed to a telegraph post in
the manner shewn in Figure 14, or the stem may be carried by an arm from
the post, or otherwise. When the socket pieces are formed of metal I prefer
to form each socket from a length of tube by inserting into the tube a
mandril, such as shewn at Figures 15*, and compressing the tube on to the
end of the mandril by two half discs formed with internal screw threads, so
forming both an internal and external screw thread upon the tube, the external
screw thread is not made quite complete, but narrow strips b' are left upon
them, which prevent the socket from unscrewing from the insulator after
it has been cemented into it.
My seventh improvement, which relates to the means of attaching the wire
to the insulator, is shewn applied to the insulator represented at Figure 15;
the insulator has in this arrangement a cast-iron bell or cap z, shewn
separately at Figure 16, carrying on its top a hook or snug y which laps
over a curved recess z. The wire is passed under the hook or snug y, and
the end of a screw w screwing through this snug is then screwed down on to
the wire jamming it downwards into the recess x, so bending the wire and
preventing it slipping through the insulator.
My eighth improvement consists in the use of lightning conductors combined
with an insulator, so that every insulator has its lightning protector; these
lightning conductors are attached either to the pole or to the arm, and are
kept in electrical connection with the earth; they are formed of iron rods

page_text: pointed at their extremities, and approach sufficiently near to the wire to
draw off the lightning electricity and prevent its bursting through the insu-
lator; the same end may be attained by attaching the pointed conductor to
the wire or the iron cap of the insulator and approximately the point of it to
the pole or neighbouring arm. A lightning conductor so arranged is shewn
at Figure 15, to be applied to the stem of the insulator; it might, however,
if preferred, be applied to the arm or post that carries the insulators, or to the
wire, as before explained. The point of the conductor is brought sufficiently
close to the wire to draw off lightning electricity from the wire and prevent
its bursting through the insulator. Lightning electricity can thus pass off
from the wire to points fixed at each insulator in place of employing a protecting
instrument composed of a double set of points, as heretofore usual.
My ninth improvement relates to the instruments employed in signalling
through long submarine cables in order to make the short sudden discharges
requisite for signalling through long cables. i place the line in electrical
connection with a hard metal ball or hammer head fixed on an axis, and
furnished with a convenient handle. When the handle is moved to the right
or to the left it strikes against one of two metallic cheeks, the one on the
right connected with one pole of the battery, and the one on the left with the
other pole, so that positive or negative impulses can be sent into the line at
pleasure. The hammer is attached to the handle by a spring with a stop on
each side, which permits it to strike a momentary blow against the cheeks,
but does not allow it to remain in permanent contact with them. This system
of momentary contacts by the ball may also be applied to the ordinary hori-
zontal finger key.
1':
Figure 17 shews a Diagram view of a transmitting instrument arranged in
the manner above described. In the arrangement of transmitting instrument
shewn by the Diagram the hard metal ball a is connected by a metal spring a¹
with the lever b, furnished with a handle 6. On each side of the lever is a
stop c, which limits the movement that can be given to it in either direction.
On each side of the ball a are cheeks d, one of which is connected with the
positive pole of a battery, and the other with the negative pole of another
battery; and, as before stated, the lever carrying the ball is in electrical
communication with the line wire. When the lever is moved to one side or
the other by its handle its movement is suddenly arrested by one or other of
the stops c; and the hard metal ball a is thus jerked forward against one of the
cheeks d, and is then at once drawn back by the spring a¹, by which a short
sudden discharge is sent through the line wire. In place of one ball being

page_text: employed to work between two cheeks connected with the batteries two balls
may be employed, both put in electrical connection with the line wire, and
one ball being employed to transmit negative currents only, whilst the other
ball is employed to transmit positive currents only, the levers carrying the
metal balls may also, as before stated, be acted on by the ordinary finger keys.
For the receiving instrument I prefer to employ a light magnetised needle
suspended vertically either on an axis or a fibre; this needle is retained in its
vertical position by the attraction of the two poles of a larger magnet suitably
placed for that purpose.
Two nose pieces of soft iron S, S¹, approach the
upper end of the needle, one on either side of it, and two other pieces N, N¹,
similarly approach its lower end. A permanent horse-shoe magnet unites the
nose pieces N and S on one side of the needle, and another similar magnet
unites N' with S¹. The needle has its south pole uppermost, which is con-
sequently repelled by the two nose pieces S, S¹, and its north pole downwards,
which is similarly repelled by the two lower nose pieces N, N¹; it there
remains in stable equilibrium between them. The nose pieces S and S¹ are
also in connection with an electro-magnet wound with fine wire and placed in
circuit with the line, and another similar magnet connects the nose pieces N
and N¹, which is also in circuit with the line, and is so arranged as to cause
the needle to deflect to the right or left whenever traversed by a current.
A Diagram view of this arrangement is shewn at Figure 18; a slight modifi-
cation of this arrangement is shewn at Figure 19; this latter arrangement
only differs from the arrangement first described in this respect that the poles
of the electro-magnets are themselves placed on opposite sides of the needle
in place of being employed to magnetize horse-shoes of soft iron, as in the first
arrangement. The signals may be read direct from the needle, or the needle
may be formed of polished steel ground to the form of a plane or concave
mirror, and reflecting an image on to a screen in the usual manner, in which
case the whole apparatus is best placed horizontally.
My tenth improvement is an arrangement to obviate the inconvénience
caused by the wandering of the spot of light in working submarine cables too
much to one side or the other of the scale, which is caused by earth currents
tending to deflect the needle continuously to the right or left. I connect the
end of the cable to the earth not directly but through a rheostat, so arranged
that one end of the rheostat is connected to earth, and the other end with a
battery which causes a current to flow continually through the rheostat. The
wire leading from the end of the cable presses upon the rheostat at some point
between the battery and the earth, and by revolving the rheostat some point

page_text: upon it will be found at which the tension exactly equals and neutralizes
that of the cable. In order to mark the mean zero point upon the indicating
scale I use two coils and two mirrors, both in connection with the cable; one
is of the ordinary construction, the other has its motions controlled and
rendered slow by a thin plate of talc moving in the air. Both pencils of light
follow each other from side to side upon the screen, one marking the signals
received, and the other serving as a steady zero point from which the motions
of the lighter needle take their departure to the right and left.
In witness whereof, I, the said Josiah Latimer Clark, have hereunto set
my hand and seal, this Seventeenth day of May, in the year of our
Lord One thousand eight hundred and sixty-seven.
JOSIAH LATIMER CLARK. (L.S.)