IMPROVEMENTS IN ELECTRIC TELEGRAPH CABLES
Year: 1858

page_text: LETTERS PATENT to Félix Marie Baudouin, of Paris, in the Empire of
France, Manufacturer, for the Invention of "IMPROVEMENTS IN ELECTRIC
TELEGRAPH CABLES."
Sealed the 14th August 1858, and dated the 20th February 1858.
PROVISIONAL SPECIFICATION left by the said Félix Marie Baudouin at
the Office of the Commissioners of Patents, with his Petition, on the 20th
February 1858.
I, FELIX MARIE BAUDOUIN, of Paris, in the Empire of France, Manufacturer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
ELECTRIC TELEGRAPH CABLES," to be as follows:-
Instead of employing an insulated copper conducting wire in the interior,
surrounded on, the exterior with a covering of wire twisted or wound round
the insulating material in the form of a screw, I dispose in the interior of
the cable the strength and elasticity which hitherto has been applied in the
external.covering of the wires, and at the same time I utilise this wire core or
heart as a conductor of electricity.
I form, for example, a cable thus: For the copper wire I substitute an
iron wire cord or rope (of six and a half-times greater cross section, in order
that it may possess equal power of conducting electricity,) composed, for
example, of six wires twisted together round a hempen heart or core covered
with bitumen, or it may be around a seventh wire surrounded by a thin
covering of hemp prepared with bitumen. The wire cord is then coated with
insulating material in the ordinary way.
If an outside bracing or covering is necessary for this new cable, I make it
in the following manner :-

page_text: First, I apply a covering of fine wires twisted in the form of a screw round
the insulating material.
Secondly, I apply a covering of hemp prepared with bitumen over the first
covering, and I repeat these two coverings alternately as often as it may be
necessary.
For paying out the cable I propose to coil it on board ship without the
outer covering, and as fast as it is payed out the covering is put on; the
number and strength of the coverings may be varied according to the conditions
of strength to be fulfilled by the various parts of the cable. If several con-
ductors are required in the cable, I prepare several cables as above and twist
them together; if the section of this compound cable should
-employ an insulated.iron conducting core or heart, between the
insulated copper conductors are inserted.
be too large, I
coils of which
I also propose to use wires of aluminium, or of alloys of aluminium, for
conducting wires.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Félix Marie Baudouin in the Great Seal Patent Office
on the 18th August 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FÉLIX
MARIE BAUDOUIN, of Paris, in the Empire of France, Manufacturer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of February, in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Félix Marie Baudouin, Her special licence that I, the said Félix
Marie Baudouin, my executors, administrators, and assigns, or such others
as I, the said Félix Marie Baudouin, 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 In-
vention for "IMPROVEMENTS IN ELECTRIC TELEGRAPH CABLES," upon the condition
(amongst others) that I, the said Félix Marie Baudouin, 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

page_text: 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.
NOW KNOW YE, that I, the said Félix Marie Baudouin, do hereby
5 declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :-
My Invention consists, first, in reversing the mode hitherto adopted in the
manufacture of submarine telegraph cables. I place in the interior of the
cable the strength of resistance, and the elasticity which hitherto has been
only in the iron wires wound on the exterior, and instead of making use of a
wire of little strength, such as copper, for the conductor (of which the tenacity
is only a fourth part that of the iron composing the external envelope,) I con-
struct my cable in such manner that the conductor of the electricity has on
the contrary a tenacity superior to that of the protecting envelope. I use for
this purpose, as the conductor of the electricity, the iron wire which has
hitherto been only employed to consolidate and protect the exterior of the
cable. For the wire or cord of copper which usually forms the electrical
conductor of submarine cables, I substitute an iron wire cord of a section six
and a half times greater, in order to obtain an equivalent conducting power.
It is sufficient to take, for example, six iron wires of about one-twelfth part of
an inch in diameter, twisted together around a core of hemp saturated with
bitumen or with other non-conducting material, or it may be round a seventh
wire of iron.
I insulate the iron wire cord thus formed by one of the several means of
insulation usual, for example, by the aid of two or three sheaths or coatings
of gutta percha, or by the aid of a single coating of this material, further
enclosed in a coating of hot bituminous matter and by a strip or ribbon of
woven material impregnated with bitumen, for the purpose of making good
the imperfections in the continuity (often imperceptible) which may exist in
the gutta percha; I then apply to this insulating envelope an envelope or
coating of hemp thread or thread of other fibrous material, rendered impervious
to electricity and to water, and lastly, to protect the insulating envelope
against injuries which may result from friction during the shipping and stowing
the cable, and also in the paying out to submerge it, and, lastly, to increase
he strength and resistance of the cable and to augment its volume and at the
ame time to diminish its specific gravity, and as a consequence, lessen the
veight of each yard immersed in the water.
Secondly, for the parts. of the cable thus constituted which require a very.

page_text: strong protecting cover, for example, the parts intended to be submerged near
the shores, where they may be injured by ships' anchors, or beaten, or dragged
by the waves against sharp projecting rocks, I apply an extra covering of iron
wire in the ordinary manner of applying such coverings to telegraph cables.
In certain cases I add to this means of protection the following improvement:
-Instead of making the covering of iron wire of a single thickness,
instead of leaving this iron wire bare, I cover the internal cable so made with
a first covering of small iron wire; I then apply a coating of hemp thread or
other fibrous material rendered non-conducting and waterproof, 1 now apply
thereto a second coating of iron wire and then another coating of hemp thread;
I compress the one coating tightly on the other of these successivo envelopes,
(which can be superposed mechanically at one time one the other; I repeat
these alternate applications of iron wire and hemp thread as many times as
necessary to afford the strength of cable required (observe the aim of this
manner of operating). It is well known that it is the superficies of the
wires which offers the resistance, and that if once impaired they break easily.
The arrangement and disposition of the parts I have indicated will have the
effect of offering greater resistance with a less mass of wire employed, and
further, to dispose the resistance so as to obtain several defenses independant
of each other which cannot be attacked except on succession.
Thirdly, in order to render the uncoiling of the cable when submerging it
easier and more sure, as also that the whole may be at first less voluminous
and less cumbersome, and that its embarkation or shipment may also be
rendered easier, I propose to delay until the time of immersion the application
of the exterior coatings or envelopes intended to lighten the cable and
augment the resistance to rupture, only applying on land on the electric
conducting core the insulating and protecting coatings which are absolutely
necessary for the preservation of the electric wire during the several operations
Having thus manufactured in the factory, with all the care and precautions
necessary, a first cable, as small as possible, I wind it on a large windlass o
drum; or it may be simply coiled in the ordinary manner in the vessel. At the
moment of immersion are added the supplementary coatings intended to lighter
the cable by increasing the volume of water it will displace when immersed
and consequently increase its comparative strength. For this purpose,
organise in the vessel destined for the purpose a system of reels or bobbin
charged with hemp threads of a suitable strength, and disposed in a manne
analogous to that employed in roperies for the manufacture of ordinary cables
All the threads coming from these bobbins converge towards a point b
means of a disc pierced with holes disposed regularly around a central openin

page_text: through which the cable in its primitive state passes, which becomes thus the
centre or core of a new cable of larger diameter, which will be manufactured
a size in proportion to the application of more or less of these outer coverings.
All the hemp threads having been attached as a covering to the internal
cable which contains the electric conductor will be drawn in by it when it is
lowered into the sea, and which threads are thereby applied to the surface in
so many lines parallel to its axis. The whole will form a tubular bundle,
which is compressed and regulated by means of grooved rollers.
All the threads composing this coating can be cemented together by means
of a viscous and impervious composition or matter through which the cable
may be passed before dropping it in the sea, or they inay be bound together
by suitable ties and especially by the spirals of hemp thread or of iron wire
supplied by bobbins carried by a plate revolving on a hollow axis, through
which the cable passes, and analogous to those used for certain rope or lace-
making purposes.
Care should be taken that several bobbins are never
empty at the same moment, and to replace them by full bobbins.
The same system of rotating plates with hollow axes may be used for
carrying all the threads of the coating, in order that they may be disposed in
a spiral direction, but the necessity of substituting full bobbins for empty ones
requires several relay plates. This arrangement besides would necessitate
á heavy and complicated mechanism while the other disposition of the threads
is simpler, and is so far preferable that, as the cable is immersed so soon as it
has received its coating or envelope, it is of no importance that this envelope
should have a perfectly regular form, provided that the threads of which it is
composed all take their share of the tension, and that they are sufficiently
connected to the cable for accompanying and taking part of the strain for
lightening it in its descent.
This mode of operating not only facilitates the embarkation of the cable by
rendering its original size or volume less, and of shipping separately the
threads intended to form the envelope which is to complete it, but it also
permits of varying the nature and the strength of the outer covering or
envelope, and also to proportion it to the conditions of strength that may be
required for the various parts of the cable according to the depth and the
nature of the places in which it is to be deposited. For instance,. for the
5 hemp threads intended for lightening the parts of the cable immersed in great
depths, I can substitute or add to the parts intended to lie on rocký bottoms
of little deptli iron wires, the strength and the number of which would.be
according to the average risks to which the cable would be exposed.
Considered as a means of lightening the cables this mode of operating can

page_text: be advantageously applied to existing cables covered with iron, and the
immersion of which presents so many difficulties in great depths.
I therefore claim the application of this mode of lightening cables at will
at the moment of their immersion, as a means of getting rid, for the most part,
of the difficulties which have been presented in the immersion of cables
charged or covered with iron because of their too great specific gravity.
For the transatlantic cable, for example, by dropping in the sea and simul-
taneously with the cable, a covering of threads of a textile material, or even a
covering of small cords supplied by separate bobbins, the volume of water
which the cable would displace would be increased, and thereby lighten or
diminish the weight of every yard of the cable immersed; and as the strength
of the threads or cords so applied would be added to the strength of the
cable (which auxiliary threads will in themselves be of little or no weight in
the water), it will result that the proportion between the absolute strength of
the whole or finished cable, and the weight of every submerged yard of the
same will increase in two ways; in other words, the number of yards suspended.
in the water which the cable would support will be increased two-fold; the
unwinding of the bobbins supplying the auxiliary threads can be regulated by
light brakes, the separate action of which will be very slight, but united.
would constitute a considerable amount of resistance, and sufficient to check
the descent of the cable without the necessity of greatly multiplying the
auxiliary threads, or the possibility of lightening the cable too much.
Fourthly, instead of a single central conductor it may be necessary that the
same cable should contain several conductors. I fulfil this condition either
by uniting together several iron wires separately isolated, which I twist
together, covering them first with a common insulating covering; and,
secondly, with a protecting envelope or cover on the whole, as above explained;
or, better still, by inserting between the spirals of the iron wire forming the
principal conductor a number of copper wires isolated from each other, as I
would thus obtain a cable of a much less section. Thus, for instance, my
iron conductor being composed of six wires, grouped in pairs, or of three
single wires, each equivalent in section to the two wires, I insert between
these three wires, or between these three groups, three thin copper wires
carefully insulated. I thus obtain a mixed conductor, composed of four special
conductors of electricity; that is to say, the three isolated copper wires and the
three iron wires, or the three groups of two iron wires, between each of which
they are inserted, the said three wires or three groups having metallic con-
nection at the beginning and termination of the cable, and forming in the
whole but one conductor.

page_text: By this disposition of arrangement I can reserve the means of separating,
at will, those three groups of iron wires, so that they may form three distinct
conductors, which will have, it is true, each a conductor power equal only to
one-third of the whole, but the separation of which may in certain cases
be useful.
This mixture of copper conducting wires with others would ensure the use
of the greatest conducting power of copper with the greatest tenacity and
strength of iron, while cables with many conductors of sufficient strength,
without being too bulky, would be obtained.
Fifthly, as metal of strength equal to iron, and with other advantages, I
propose to substitute aluminium for copper to form the central conductor of
submarine cables. This new metal, as well known, is as good a conductor of
electricity as copper, and has a specific gravity of only one-third of that metal.
and a tenacity nearly equal to iron.
I take, for instance, an aluminium wire having a diameter of about one-
twelfth (r) part of an inch; or, if preferred, a cord composed of three thin
aluminium wires having a diameter of about the twenty-second (27) of an
inch, and twist them together. I then coat, by known processes, this electric
conductor with insolating coatings or envelopes, thin, but carefully put on
over all. I apply a hemp or impervious silk protecting cover or envelope,
and I thus obtain a small cable having only a diameter of about one-eighth
(h) of an inch, the specific gravity of which would-be about 1.36 only, which
consequently, would weigh very little in water, and which might support a
very great number of yards of itself suspended in the water without breaking;
as a consequence of its little volume, and of its little weight in water, the
coiling on board and the delivering at sea would be rendered very easy, and
it could be hove almost like a log line, without any brake or machinery.
As a means of preserving the telegraphic cables formed with thin conductors,
such as aluminium conductors from the electric interruptions which sometimes
occur in submarine cables without there being any break in their whole length,
1 employ the following arrangement:-Instead of twisting together several
wires of aluminium to form the conductor, I use a single conducting wire of
a sufficient section. Around this wire, stretched in a right line, I wind one
or several thin wires of well cleaned aluminium, copper, or iron, in such
manner that the spirals are closely wound and touch each other, and so that
the rectilineal internal wire may be covered with an envelope of thin metallic
wire, like the base covered strings of musical instruments. This assemblage
will form a metallic mass affording a rectilinear passage to electricity, and
this even if the central conductor of the cable had suffered a distension which

page_text: had broken the principal and rectilinear wire, the thin metallic wires disposed
in helices being capable of sliding on the smooth surface of the internal wire
would be stretched without breaking. Thus the two separated parts of the
internal wire would remain in metallic continuity by these thin wires, which
would give to the electricity a passage more obstructive, perhaps, but suffi-
cient, especially because of the shortness of the separation of the principal
wire in the electric cable. This arrangement is not alone applicable to
aluminium conductors. I propose to apply it to copper conductors, and to iron
or other metal conductors.
I also propose the use of alloys of aluminium which possess great solidity
& strength.
Lastly, I will remark that in the same manner as I combine iron with
copper,
I can also combine aluminium or its alloys with copper for forming
mixed cables, including several conductors, in a small space, but at same
time presenting relatively great resistance to breaking in water.
Having described the nature of my Invention, and the manner of per-
forming the same, I declare that what I claim as my Invention to be pro-
tected by the herein-before in part recited Letters Patent is,-
First, the improvements in submarine telegraphic cables, consisting in trans-
ferring into the interior of cables the strength and elasticity which has
hitherto been disposed on the outside or covering of iron wires with which
they have been coated, and in substituting for the central conductors of
copper conductors of metal of great tensile strength, such as iron, wire
cords or ropes, for instance..
Secondly, the improvements consisting in the application of protecting iron
wire coverings or envelopes, when such protection is required, which improve-
ments consist in alternally superposing layers of iron or steel wires and layers
of textile impervious material.
Thirdly, the improvement consisting in not covering when on shore the con-
ductor of the cable, except with coatings or envelopes absolutely necessary for its
insulation and its provisional preservation, and in applying, when on board, at
the time of the immersion, the coverings or envelopes intended to complete,
lighten, and strengthen the cable, which admits of using envelopes or cover-
ings of a nature and strength appropriate to the local conditions which are to
be satisfied.
Fourthly, the application of this method of lightening and supporting to
heavy cables, such as already exist, in order to get rid of the difficulties pre-
sented during the submersion.
Fifthly, the means described of constituting a multiple conductor, possessing.

page_text: at once great strength and small volume, which means consists in joining,
separately, insulated copper wires to the iron wire cord or rope forming the
principal conductor of the cable by interposing these isolated copper wires
between the spirals of the iron wires of the cord, which spirals may besides,
if required, be in connection at the ends of the cable to form altogether a
single conductor, or they may be maintained isolated to form as many separate
and distinct conductors.
Sixthly, the modification which consists in using aluminium for the con-
ductors of submarine cables, in order to combine great conducting power
with great lightness and great tenacity, and thus to obtain submarine cables
of very small diameter, but offering relatively, when under water, very con-
siderable resistance to breaking, at same time their immersion would be very
easy to conduct.
Seventhly, the use I make of the alloys of aluminium for the improvement
of conductors of submarine cables..
Eighthly, the combination which I can make of all these various metals,
aluminium, and its alloys, copper and iron, so that I may take advantage of
the greater strength of some of these metals, and of the greater conducting
power of the others.
In witness whereof, I, Felix Marie Baudouin, have hereunto set my
hand and seal, this Thirteenth day of August, in the year of our
Lord One thousand eight hundred and fifty-eight.
F. M. BAUDOUIN.
(L.S.)