IMPROVEMENTS IN THE MANUFACTURE OF TELEGRAPHIC CABLES OR CONDUCTORS, AND IN APPARATUS THEREFOR
Year: 1880

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Company, Patent
Solicitors, at Frankfort on the Main, in the Empire of Germany, for an
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF TELEGRAPHIC CABLES
OR CONDUCTORS, AND IN APPARATUS THEREFOR." A communication from
Marcus Marcellus Manly, Robert Patterson Manly, and William James Philips,
of Philadelphia, in the County of Philadelphia and State of Pennsylvania,
United States of America.
COMPLETE SPECIFICATION filed by the said Frank Wirth at the Office
of the Commissioners of Patents on the 10th April 1880.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort on the Main, in the Empire of Germany. "IMPROVEMENTS IN THE
MANUFACTURE OF TELEGRAPHIC CABLES OR CONDUCTORS, AND IN APPARATUS
THEREFOR.' A communication from Marcus Marcellus Manly, Robert Patterson
Manly, and William James Philips, of Philadelphia, in the County of Philadelphia
and State of Pennsylvania, United States of America.
"
The Invention relates to an improvement in the manufacture of insulated and
protected telegraphic cables or conductors, consisting of wires or a wire surrounded
by a tube and enclosed insulating material.
In a process heretofore used for the manufacture of such cables the enclosing
tube and wire are kept under tensile strain while the tube is being filled with
molten insulating material, and during the entire operation of filling there is applied
to the outside of the tube a degree of heat equalling about that of the melting
point of the insulating material. In the apparatus for carrying out this process
the tube and wire are suspended vertically, secured at their upper ends and strained
downward, and the insulating material is poured into the upper end of the tube.
The heating of the tube outside was intended to expel the air therefrom and
prevent the formation of bubbles or air pockets in the composition, to prevent the
too sudden cooling and resulting shrinkage of the composition from the tube, and
also to prevent the congelation of the composition during its descent and before its
proper settling. Satisfactory results are not obtained from this old process, for
notwithstanding the precautions taken bubbles or air pockets will occur in the
insulating material in great number, and an equable and compensating expansion
and contraction does not take place between all the elements of the cable..

page_text: To overcome these disadvantages of the old process is the object of the present
improvement, which consists,-
First. In fixing the tube and wire at their lower onds, straining them constantly
upwards, and filling the tube by forcing the molten insulating material into its
lower end. The insulating material rising in the tube against the action of gravity
forces the air out before it, and is kept well condensed, so that there is no danger
of the formation of bubbles or air pockets or vacuums. The gradual rise of the
heated material causes the tube and wire to expand longitudinally before it, and
this expansion is taken up by the upward strain upon them, so that they will not
siip or become separated from the composition. By this improvement I am enabled
to dispense with the external application of heat to the tube, and have secured
much better results as regards the avoidance of bubbles and vacuums than by the
old process.
A further improvement consists in keeping the wire and tube under a yielding
tensile strain while cooling after filling, and keeping the insulating material at
the same time under pressure, applied at both ends of the tube, through columns of
said material in a molten state, thus furnishing a constant supply to compensate
for any contraction which may occur.
Another improvement relates especially to the manner of introducing the wires
into the tube when a cable is to be formed having more than one wire. This
improvement consists in threading the ends of the wires through perforations in two
plugs, one of which is of a size to pass through the tube to be filled, and the other
adapted to be secured in the end of said tube, securing the said ends of the wire to
the plug for passing through the tube, then placing the two plugs in the upper
end of a tube, the travelling plug being introduced first, and the other secured
against inward movement, and then drawing the travelling plug and with it the
wires through the tube to its opposite end. The wires are thus prevented from
becoming entangled with each other, and the movement of the close-fitting plug
corrects any bends or indentations in the tube.
This Invention also consists in cooling from the bottom gradually upward a
vertical tube surrounding wires under yielding upward tension, and filled with
molten insulating material, and being 'itself under upward tensile but yielding
strain. By this improvement the contraction of all the members of the cable is
caused to be in a downward direction, and shrinkage of the cooling insulating
material either from centre or circumference at any point is compensated by the
settling of the superincumbent molten material. In the old process the introduction
of cold air into an enclosure surrounding the entire tube, and cooling said tubo
throughout its whole length at the samo time frequently resulted in detachment of
the insulating material from the tube by shrinkage from its circumference, and
at other times in separation of the cooled material at various points.
Still another improvement consists in twisting each section of cable (the wires
and insulating material) after it has been filled and cooled. This is to permit the
cable to be reeled without displacing the wires. When the wires were left straight
and the cable was wound upon a reel it was found that the ends of the outer wires
were drawn inwardly from the ends of the tube, and the inner wires were forced
into contact with each other; but when the cable is twisted each wire continually
changes position on account of the spiral form given it, and therefore when the
cable is reeled all the wires are equally inner and outer wires, and bend equally
without interfering with each other. Neither are they drawn into the tube, as the
coils permit them to extend and contract in correspondence with the coils of the
tube around the reel. To twist a section of cable I clamp a fly wheel to its lower
end, the section being suspended and firmly fixed at its upper end, and turn the fly-
wheel about fifteen times, more or less.
This Invention further consists in certain improved constructions of mechanical
devices for carrying into effect the improvements hereinbefore set forth, and which
will be hereinafter described.
The Invention also relates to an arrangement of the wires in a multiplex insulated

page_text: telegraph cable having for its object to reduce retardation and interruption of the
electric currents by the inductive influence of the wires upon each other. It
consists in providing a telegraphic cable comprising two or more conducting wires
with an independent wire adapted for connection with the ground at points inter-
mediate of the length of the cable; the independent wiro is not connected with the
conducting wires of the cable at any point, nor with any other than ground
terminals, and its office is to receive and conduct to the ground a portion of the
currents induced by the cable wires, said induced currents Howing over the ground
wire as the shortest route to an equilibrium, or that having least resistance of any
conductor within the inductive influence of the said cable wires, all as more fully
hereafter described and explained.
In the Drawings,―
Fig. 1 is a vertical section of the apparatus for the manufacture of the separate
sections of the cable.
•
Figs. 2 and 3 are detached views of the upper and lower heads for holding the
tube.
Fig. 4 is a detail sectional view illustrating the manner of introducing several
wires simultaneously into a tube.
Fig. 5 is a view of the lower retaining plug.
Fig. 6 is a diametric section of joint which may be used between two sections
of cable.
Fig. 7 shows two lapping wires enclosed by a sleeve.
Fig. 8 shows the wires as simply abutting in the sleeve, and connected by solder
joint.
Fig. 9 illustrates the mould for forming the joint of insulating material.
Fig. 10 shows a clamp used for compressing the joint sleeve.
Fig. 11 illustrates the modo of twisting the cable.
Fig. 12 represents a diametric section of a portion of a telegraphic cable con-
structed with a central independent wire for ground connection.
Fig. 13 shows two sections of tube connected by a sleeve, and the ground wire
in position to be inserted.
Figs. 14 and 15 respectively illustrate additional modes of forming joints between
two sections of cable.
The letter A in Fig. 1 designates a lead tube with one wire arranged therein and
ready to be filled with an insulating material. The lower end of this tube is firmly
secured to a centrally bored stationary head B, which is secured in position by
three tie rods C, which are secured to said head by having their screw-threaded
upper end passed through ears c projecting at equal distances apart from the
perimeter of the head, and retained by suitable nuts. The lower ends of these tio
rods are also screw-threaded and pass through beams D, which form a portion of
the structure enclosing the apparatus, and also through oblique faced nut seats d
arranged upon the under sides of the beams, and against which are screwed the
retaining nuts d². Any other suitable means may of course be used for securing
the head B in position. The bore of this head is of size to receive snugly the
tube A, and flares downwardly, so that when the end of the tube is inserted
therein, and is by a suitable tool flared snugly against the surrounding wall of the
head, as shown in Fig. 1, said tube will not be withdrawn from the head by the
upward tensile strain to which it is to ho subjected. The head B is provided with
a lateral passage b connecting with a supply pipe I, to be hereafter described, and
the lower end of said head is threaded to receive a screw cap B'. The upper end
of said head is also screw-threaded for a purpose which will be hereafter
explained.
The letter E indicates a vertically movable upper head arranged directly above
the lower head B, and having a similar central bore flaring upward for a similar
purpose. The upper end of pipe A is shown flared in this upper head. This head E
has a lateral passage e connecting with its boro and with an attached pipe E' bent
upward and terminating in a funnel e', and said head is provided with two radial

page_text: projecting cars diametrically opposite each other and pierced to embrace guide
rods F which extend vertically between and are secured to the cross-benins DI and
D" of the enclosing structure. When the head is in its lowermost position the ears
frest upon the beams D". The head E is provided with other and shorter ears g
also diametrically opposite each other, and to which are secured the feet or lower
ends of an elongated bail or arched rod G, and to the top of this bail is fastened a
rope extending upward over a pulley h, and thence to a windlass H provided
with a drum wheel H' having around and depending from it an endless rope H",
after the manner of hoisting apparatus, said rope being provided with loops or
rings to which may be attached weights w, the purpose of which will be hereafter
explained.
-The-supply pipe I, heretofore referred to as connected with the passage b in the
lower head B, extends horizontally to a convenient-distance-from the head, and then
vertically to a point somewhat higher than the upper head E will ever be drawn in
usc. The pipe I terminates at its top in a reservoir J having a capacity preferably
somewhat greater than that of the tube sections which the apparatus is intended to
fill, and this reservoir J and the supply pipe 1 (the latter to a point a short distance
from the head B) are surrounded by a continuous steam jacket K connected by a
pipe with a suitable steam generator, which may be located as convenient. From
the upper portion of the steam jacket K a pipe i leads to a smaller steam jacket K¹
which surrounds but is disconnected from the pipe E' leading from the upper
head E. The lower and horizontal portion of the main steam jacket K rests upon
standards L, preferably of cast iron, cast with seats to receive it, and standing upon
the lower floor of the enclosing structure. The pipe I is provided with a stop-cock
between the head B and the lower terminus of the steain jacket K.
The letter M indicates a vertical tube of, say, about four or five times the diameter
of the cable tubo A, and having its upper end flanged and secured to the beams D₁.
The lower end of this tube M terminates at a suitable distance (in practice about
four feet) above the lower head B, and has at its edge a slightly projecting flange m
screw-threaded on its periphery. At a distance above this flange, equal to the
distance between the end of the tube and the head B, said tube has another flange
m¹ projecting the same as the lower one, and also screw-threaded on its periphery.
The diameter of these flanges is the same as that of the upper screw-threaded portion
of head B. The letter M designates a movable tube section having a diameter
slightly greater than that of tube M. This tube section has at each end a very
narrow inwardly projecting rim, internally screw-threaded and of a size to engage
with the upper screw-threaded portion of head B and flanges m and m¹. Near its
lower end the section M' carries a screw nipple m" which may be connected by a
suitable hose or pipe m³ with the discharge pipo of a force pump M², while a waste
pipe leads from its top outside of the building. Said tube M serves as a water
jacket for the tube A in the process of cooling. The lower portion or section M¹ of
this water jacket is secured to the lower head by its screw connection, and to the
upper portion by means of a screw flange m when in use, and may be removed
upward and secured to permit access to the tube for twisting, as hereinafter
explained and as illustrated in Fig. 11. If the mass of metal (tube and wires)
preponderates over that of the filling, as in the case of many large conductors in a
large tube, the temperature of said mass may be brought to the proper point before
filling the tube by filling the jacket with warm, say, steam heated water, and
changing the temperature of the latter as the process of cooling may require.
Now supposing the apparatus to be adapted to treat sections of tubing of a length
of one hundred feet, more or less, lead tube being generally used, such a section is
cut from a reel or coil and passed downward through the upper head E and the
water jacket, one end flared by a suitable tool in the upper head E, and the other
lowered into the lower head B and flared therein. Flaring plugs should be tem-
porarily forced into the end of the tube. The upper head E is then drawn upward
by means of rope and windlass until the tube is stretched straight as nearly as
possible by this means, and then weights are attached to the hoisting rope to keep

page_text: the tube in this condition under upward tensile strain. A uniform, and at the saine
time adjustably uniform, tension for all of the operations of expansion, stretching,
insertion of wires, and tension during the process may be also obtained by substi-
tuting an adjustable friction clutch on the shafts to which the ropes are attached,
in place of the windlass and weighted rope. The plugs are now to be removed, and
with a suitable tool the tube is pierced with openings coinciding with the passages
b and c in the upper and lower heads respectively.
The required number of sections of wire W (somewhat exceeding the tubo in
length, for convenience of fastening at their ends) is now to be cut from a reel or
coil and given a preliminary stretching for straightening, and one end of each is
then passed through a perforation in each of two plugs N and N¹ placed end
to end, as shown in Fig. 4, but before these plugs are inserted in the tube. The
former of these plugs (N) has its main portion (n) formed of a size to fit snugly
within the normal bore of tube A, while its other end flares to fit within the
portion of said tube which is flared within the upper head E. The plug N', which
is in fact only a half plug, as will presently appear, is hollow and is formed
throughout its length to fit the bore of the tube, and is provided at one end
(intended for its lower end) with an internal screw thread, into which may be
screwed a plug n provided with a bail n".
After being passed through the plugs the ends of the wires are knotted or wound
upon a pin or bar to provent them from being withdrawn from plug N', and the
plug n¹ is theu screwed into said plug, and a steel tape or ribbon o has then one
end secured by a hook to the bail n on the end of plug n¹ while the other end
is passed down through the tubo A under a pulley p mounted on the floor of the
building, and thence to a windlass P to which it is secured. The two plugs N
and N₁ are then placed in the mouth of the tube, the plug N' first, and by means
of the windlass and tape this plug N' is then drawn downward (and with it the
wires) through the tube below the supply pipe I. The plug n is then removed
from plug N and a plug N2, the lower portion of which is flared to fit the flared
end of the tube, is screwed into the bottom of said plug N¹. The practice is to
first draw upward through the tube a steel mandril slightly larger than the tube,
which expands it proportionately, and as it is under tension at the top (as herein-
before explained) this operation gives it a uniformly slight stretch at every point
of its length and renders it perfect at every point.
The wires may be threaded directly from a rack of spooled wires, and it may be
found desirable to draw them upward instead of downward, putting the solid plug
at the bottom and the plug in two parts at the top.
The upper ends of the wires are knotted together and attached to the end of a
roper passing directly upward over a pulley & properly supported under the arch
of the bail G so as not to interfere with the movement thereof, and from this pulley
the rope passes to a windlass R constructed and equipped in all respects similarly
to the windlass H heretofore described. By means of the windlass R and its rope
the wires are now to be stretched upward to a degree of tension which has been
found by previous experiment (with wires outside of a tubo) to be sufficient to
render them straight and taut, and they are maintained under the upward tensile
strain by means of weights w' attached to the hoisting rope R". Or instead of
the weighted ropes friction clutches may be applied to the windlasses, as before
stated.
The tube and wires having been thus placed under upward tensile strain the
reservoir J is filled with insulating material in cakes or lumps of suitable size, and
the cock in the steam pipe k is turned to admit steam from the steam generator
within the steam jacket K. The steam soon causes the insulating material in the
reservoir to melt and flow downward through fine strainers properly arranged in
the supply pipe. After it has been thoroughly melted and fills the pipe I more
material is placed in the reservoir and allowed to melt until both reservoir and pipe
are full, and then the cock i¹ of the supply pipe is turned to permit the molten
material to flow into the tube A through the passage b and the coincident aperture

page_text: in the tube, and as it rises in said tube the air is driven out before it and escapes
through the pipe E. The reservoir is supplied with more material as the level of
that melted falls, and when the molten material reaches the top of tube A it flows
into the pipe E¹ and rises to the level of that in the reservoir, being kept melted
in the pipe E by steain passing through the pipe i and the small steam jacket K².
Thus it will be seen that the column of molten material within the tube A is
brought under pressure of the columns in the pipes I and E¹ respectively, so
that any contraction by cooling is constantly compensated. The steam is
allowed to flow through the steam jackets for some minutes after the filling
is completed to insure a perfect setting of the material, and when it is cut off
the-force pump M² is put in operation to force water through pipe m³ into the
lower end of the water jacket or section 1; in which it is caused to gradually
rise around the tube A, cooling it gradually upward so that the contraction of
all the members of the cable is downward, and the insulating material assumes its
ultimate condition and position in proper relation to the wires and tube to obviate
its separation from the same and to insure the perfect filling of the former. After the
water jacket has become filled the water is allowed to overflow through the waste pipo
until the cable is coll. A modification (perhaps preferable) of the mode of operation
consists in admitting the insulating material within the tube at the bottom, and at
the same time admitting water or a cooling compound within a jacket surrounding
the same, and permitting the material forced in at the bottom to overflow through
the opening in the upper movable head. The action of the water or cooling
compound is to gradually line the tube with the solid insulating material from the
circumference to the centre, and the presence of the surrounding liquid removes any
vibration that might be communicated from the earth, and renders possible the
manufacture of the tubo in lengths of one hundred feet and upwards. When the
material ceases to overflow at the top the upper column above spoken of is attached
and remains until the water is withdrawn. The overflow is replaced in the
reservoir. After the cable has cooled the lower section M¹ of the water jacket is
by means of suitable handles unscrewed from the head B and flange m, and elevated
so that its upper thread can engage with flange m¹ and its lower thread with
flange m, and it is thus supported out of the way. The section of cable is then
sawed off at a convenient distance above the head B, and a fly wheel Z³, Fig. 11,
slipped on and clamped firmly, and the upper end of the tube being tightly clamped
in the upper head E the entire cable is twisted as much as may be desired, say,
by turning the wheel about fifteen revolutions. The wheel is then removed, the
tube sawed off at the upper end (the head E being raised for this purpose) and
lowered by means of rope and windlass to the joining table, the wires being left
projecting properly at each end to facilitate the joining of sections together. In
joining sections they are so placed that the wires lap about three fourths of an
inch, and each two adjacent lapping wires are then soldered together, commencing
first to solder the lowermost wires as the cable lies. Before commencing to solder
the wires a rather close fitting sleeve with slightly flaring ends of the same metal
as the tubes, indicated by V, Figure 6, is passed over the end of one of the sections.
While the wires are being soldered they are supported in proper position by very
thin perforated plates or templates v and v of hard rubber or mica, or cast in
hardened shellac or other insulating compound, the templates V having their
perforations somewhat further apart than the wires in the tubes. After the wires
are then soldered the joint is enclosed by a mould U, Fig. 9, composed of two semi-
cylindrical sections hinged together at two of their longitudinal edges and provided.
with latching devices at their opposite edges. From the middle of one of these
sections leads a pipe U curving and extending above the other section and
terminating in a funnel u'. From the middle of the other section a short straight
pipe U projects vertically. This mould is of a proper length to overlap, and of a
proper diameter to snugly embrace the ends of both sections of cable, say, about
three inches, and when applied thereto both the pipes U₁ and U" extend upward,
the former serving as a filling pipe and the latter as an air vent.
Molten insulating

page_text: material is then poured into the funnel u¹ and flowing through the pipe U' rises
in the mould, surrounding the wires and forcing the air out through the tube U".
When it begins to overflow the vent tube the pouring is stopped and it is allowed
to cool. When cold the mould is removed, the joint is wiped with a non-hardening
insulator, such as balsam of fir, to prevent any capillarity, the sleeve V is drawn
over the joint overlapping the ends of both sections, and is compressed upon said
ends and the joint by means of clamp X, shown in Fig. 10, the construction and
operation of which will be readily understood from the Drawing. Care should be
taken to avoid compressing the flared ends of the sleeves. When the sleeve has
been compressed a plumber's wipe-joint VI should then be formed at each end of
said sleeve, the metal of the joint extending into and also enclosing the flaring
ends of the sleeve, as shown. This forms a very strong connection between the
cable sections. While the wipe-joints are being formed cold water, preferably ico
water, should be caused to flow or pour around the tube and sleeve at each side of
said joints in order to prevent the wires from settling.
The plug N may have its screw thread omitted and be perforated to correspond
with plug N', and after the latter is drawn to its place at the lower end of the
tube, the ends of the wires may be straightened and passed through said plug N
and wrapped around a cross bar or ring to prevent their withdrawal, the plug N'
being then inserted in the flaring end of the tube and drawn snugly therein when
the wires are tightened. When this arrangement is used the cap B² should be
screwed upon the head B to prevent leakage of the composition or insulating
material. The cap may also be left off the lower head B, and the wires may pass
through a perforated flaring plug and be secured below said bead to a ring in the
floor or to other permanent fastening.
If the tube should be much battered or indented it would be well to draw a
steel cylinder through it by means of the steel ribbon and windlass.
Instead of simply soldering the wires together in forming the joint, as heretofore
explained, the lapping ends of. each two wires may be enclosed in a light copper
sleeve and the sleeve and wires soldered together, as shown in Fig. 7, in which 8³
designates the sleeve, and w, w, the wires.
If the solder should break, the sleeve still connects the wires.
In cables where the wires are close together the wires do not lap, but simply
abut end to end, and the sleeve which connects them is circular as shown, a',
Fig. 8, except a small aperture in the top, and has thickness equalling the mass (in
cross section) of the wires to be joined. The sleeves are also tinned on the inside
in order to insure good electrical connection with the wires.
Referring to Fig. 12, the letters A*, A*, indicate the ends of tubes enclosing the
several wires b* forming the direct conductors of a telegraphic cable, and a suitable
insulating material surrounding and supporting said wires, which project beyond
the ends of the tubes to permit of splicing in the ordinary manner, as shown at
c. The letter D* designates the independent wire which receives a portion of the
inductive influence of the other wires, and conducts the currents to the ground.
This wire 1 prefer to locate in the centre of the tube, and equidistant from the
other wires which surround it. As shown in Fig. 12, the ends of the independent
wires D project somewhat beyond the ends of the tubes, and are provided
at their tips respectively with right and left hand screws. These tips are
connected by a sleeve e screw-threaded to correspond therewith, and having a
projecting collar f* which is also screw-threaded to receive the end of a ground
wire g, the opposite end of which terminates in a ground plate h°. This ground
wire y passes through a holo in a sleeve 1 which connects the two tubes A*, A*,
and when not applied is provided with an aperture 1*.
The complete section of cable may be manufactured by any of the known
methods of making this class of cables, the arrangement of the wires being
preferably as above described. In joining the ends of the sections of cable, as
shown in Fig. 12, the sleeve I* is first slipped upon one of the sections, and after
the splicing and connecting of the wires is completed, said sleeve is moved to

page_text: embrace the ends of both sections as shown, taking care that the lower hole in the
sleeve I shall come in line with tho screw-threaded collar f* projecting from the
coupling sleeve e*. The ground wire g is then inserted through the hole in the
sleeve 1, and its screw-threaded tip engaged with collar f*. Care must be taken
of course that the ground wire g* does not come in contact with any of the wires
6*. The connections having all been properly made, and the sleevo in proper
position, it is then firmly soldered, preferably with the ordinary plumber wipe-
joints, and then is filled through the aperture i* with molten insulating material,
similar to that used in the tube section. The aperture and the hole through
which the ground wire passes, are closely sealed by soldering, and the joint is
complete. Fig. 13 shows the sleeve I* screwed in place, and the ground wire in
position for insertion....
Instead of using the screw coupling for the independent. wire, this wire may be
spliced in the same manner as the other wires. In this case the ground wire must
be connected with the independent wire by winding or coiling the former around
the latter, and the free end of the ground wire is then passed into the sleevo I*
(which should be draw partly off the tube for that purpose, as shown in Fig. 15),
and out through the hole therein, the sleeve I* may then be moved to the position
shown in dotted lines, the ground wire drawn straight (as also shown by dots), the
ground plate attached, and the subsequent steps in forming the joint are the same
as above described as to the soldering and filling of the sleeve 1* with insulating
material.
In the mode of joining the sections illustrated by Fig. 14, after the wires are all
spliced and the ground wire attached, a sleeve like mould, which is composed of
two longitudinal parts, and provided with a pouring aperture and an aperture
formed by recesses in the edges to surround the ground wire, is placed around the
ends of the tube sections, and an insulating joint moulded. The mould is then
removed, the insulator and adjacent ends of tubing wrapped with sheet lead, as
shown in section at 8*, Fig. 14, and another mould, one half of which is shown at
m, having an interior concavity similar to the exterior shape of the sleeve I*,
Fig. 12, is placed around the joint. This mould is then filled with molten lead,
and a solid joint is thus cast, connecting the two sections of tubing. The mould
should be then removed. The sheet lead 8 it will be understood is simply to
protect the insulating joint from being melted while the molten lead is being
poured in the mould. Instead of casting the lead joint, it may be "wiped" on
according to the practice of plumbers.
I do not confine myself to cables having enclosing tubes and fusible insulating
material surrounding the wires, as it is obvious that ground connections may be
applied to an independent wire in any cable having two or more direct conducting
wires, and the manner of applying uy Invention will be suggested by the circum-
stances and general character of the cable in connection with which it is proposed
to be used.
Having now described the nature of the said Invention, as communicated to me
by my foreign correspondents, and the best modes known to me of carrying it into
effect, I wish it to be understood that what I believe to be new and desire to
protect under the hereinbefore in part recited Letters Patent is,―
First. The improvement in the process of manufacturing insulated and protected
telegraphic cables, the same consisting in keeping a metallic tube and an enclosed
wire or wires under upward longitudinal tensile strain, and at the same time intro-
ducing a molten insulating material into the lower end of said tube, and causing it
to gradually rise and fill the same and surround the enclosed wire or wires, the
tube and contained insulating material being then cooled and prepared for use in
any desired manner.
Second. The improvement in the process of manufacturing insulated and protected
telegraph cables, tho same consisting in keeping a metallic tube and an enclosed
wire or wires under yielding upward tensile strain, and at the same time introducing
a molten insulating material into the lower end of said tube, and causing it to

page_text: gradually rise therein and fill the same, and subsequently keeping the insulating
material within the tube under pressure while cooling by means of columns of
similar molten insulating material bearing against the opposite ends of tho column
within the tube.
Third. The improved method of introducing a scries of wires into the tube, the
same consisting of threading the ends of the wires through the tube perforated or
template plugs, securing them to the plug adapted to pass through the tubo, and
then forcing said plug through the tube.
Fourth. The improvement in the process of manufacturing insulated and protected
telegraph cables consisting in filling the tube with molten insulating material while
said tube and its enclosed wire or wires are under a yielding upward tensile
strain, and then cooling said tube and its contents gradually from their lower onds
upward.
Fifth. The combination of the clevated reservoir, the supply pipo leading down-
ward therefrom, the stationary lower head B connected with said pipe and adapted
to receive and retain the lower end of the tube, the upper vertically movable head
adapted to receive and retain the upper end of the tube, and a suitable mechanism
for moving said head upward.
Sixth. The combination of the clevated reservoir, its supply pipe leading down-
ward, the stationary lower head connected with said pipo, the upper movable head
and mechanism for moving it upward, and devices for supporting a wire or wires
under tensile strain through a tube supported vertically by said heads.
Seventh. The combination of the upper head E, the lower head B, the plugs N
and N¹, the tube A, and means for forcing the plug N¹ through said tube.
Eighth. The combination of the upper and lower heads for holding the onds of
the tube, means for forcing molten insulating material into the lower end of the
tube, and a device for cooling the tube gradually from its lower end upward.
Ninth. The improvement in the process of manufacturing insulated and protected
telegraph cables consisting in twisting the tube and enclosed wires and column of
insulating material after the section of cable has cooled.
Tenth. A telegraphic cable comprising two or more conducting wires proper or
for direct current, and an independent wire adapted for connection with the ground
at points intermediate of the length of the cable.
Eleventh. The mode of joining two sections of telegraph cable composed of tubes
enclosing wires surrounded by an insulating material which fills the said tube, the
said mode consisting in locating the ends of the tube at a suitable distance apart,
spreading the projecting wires slightly and supporting them by templates of insu-
lating material, then forming joints between the wires, next surrounding the wire
joints with insulating material by means of a suitable mould, and then slipping a
sleeve with flared ends from one of the tube sections upon which it has been pre-
viously placed, so that it will overlap the adjacent ends of both tube sections, and
finally securing said sleeve to both of said tube sections by solder wipe-joints
surrounding and entering the flared ends of said sleeve.
Twelfth. The combination of the two tube sections, the sleeve V having flaring
ends, the wipe-joints V₁ securing said ends, the wires connected by suitable joints,
the templates and v₁ of insulating material supporting said wires, and the
insulating material in said tube sections connected by a similar insulating material
in the sleeve.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand
and seal, this Tenth day of April, in the year of our Lord One thousand
FRANK WIRTH. (L.S.)