IMPROVEMENTS IN ELECTRICAL TELEGRAPHY
Year: 1865

page_text: LETTERS PATENT to Richard Laming, Member of the Royal College
of Surgeons, 38, Priory Road, Kilburn, in the County of Middlesex,
for the Invention of "IMPROVEMENTS IN ELECTRICAL TELEGRAPHY."
PROVISIONAL SPECIFICATION left by the said Richard Laming at the
Office of the Commissioners of Patents, with his Petition, on the 29th
August 1865.
I, RICHARD LAMING, Member of the Royal College of Surgeons, 38, Priory:
Road, Kilburn, in the County of Middlesex, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN ELECTRICAL TELEGRAPHY,"
to be as follows:-
The following facts are well known to electricians,-1, that all the electricity
which enters an insulated metallic wire rests eventually on its surface as
charge. 2, that the said wire baving one of its ends to earth, its capacity to
conduct electricity is as its sectional area, and not as its surface; from which
facts I infer that electrical charge and electrical conduction are separable
one from the other. It is further known; 3rdly, that electrical signalling
depends upon the electricity, which is conducted through a metallic wire, and
not upon that which rests upon its surface, from which I infer the desirability
of separating electrical conduction from electrical charge.. Again, it is known
that.à metallic wire covered with a solid insulating material, and either sub-
merged or interred, its far end being uninsulated while its near end is
receiving electricity from some rapidly giving source, is particularly subject

page_text: to accumulate charge upon its surface in comparison with a naked metallic
wire simply insulated by suspension in the air between the source of electricity
at one of its ends and the earth at its other end, and to this fact is ascribed
the great amount of retardation in signalling which is so objectionable in
marine telegraphy.
Now, it is one of the objects of this Invention to diminish or repress retar-
dation in submarine or subterranean conductors, or cables as they are termed,
by separating more or less perfectly the undesirable charge from the signalling
conduction, which it proposes to do by providing for each a separate conductor,
one offering an enveloping surface to be maintained in a state of charge, and
the other an inclosed sectional area for the conduction, the two conductors
being separated from each other, and from the surrounding earth or water by
interposed solid insulators. In the construction of the signalling conductor I
propose to replace the copper usually employed by steel or iron, for sake of
the greater tenacity of the latter metals, their inferior specific conductivity
being compensated for by the smaller quantity of electricity to be introduced,
while their velocities of conduction are, if not equal to that of copper; at
least great enough in either instance for all practical purposes. The outer
conductor to receive the charge may be of any soft metal, selected for its
flexibility, or of steel or iron for its greater strength.
Another object of this Invention is to facilitate the raising of marine cables
for repairs, and consists in making them of light specific gravity, and in sinking
them by the use of moveable jointed metallic rings or weights, sliding down
upon them while in the act of submergence; the weights being capable of
passing off from or towards one or more ends of a cable on an end or a bight
being subsequently lifted..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Laming in the Great Seal Patent Office on the 27th
February 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
LAMING, Member of the Royal College of Surgeons, 38, Priory Road, Kilburn,
in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of August, in the year of our Lord.
One thousand eight hundred and sixty-five, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors; give and grant unto me, the:

page_text: said Richard Laming, Her special licence that I, the said Richard Laming,
my executors, administrators, and assigns, or such others as I, the said
Richard Laming, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there--
after 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 ELECTRICAL TELEGRAPHY," upon the condition (amongst others) that I, the
said Richard Laming, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-.
ticularly 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.
NOW KNOW YE, that I, the said Richard Laming, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
This Invention has for its object, firstly, to suppress either altogether or to
a great extent the formation of charge on the conductors of electrical tele-
graphs, whether submarine, subterranean, or atmospheric, while in use for
conveying signals from one place to another, and thus to remove or diminish
retardation of which charge is the cause; and, secondly, to sink subaqueous
electrical cables so as to make their recovery in case of need less difficult and
uncertain. It is well known that while the surface of a metallic con-
ductor is occupied by electrical charge its substance can be employed for the
conduction of electricity from one of its ends to the other, and also that the
electricity resting as charge upon a telegraph wire, though perhaps many
thousand times greater than that which is active in signalling, contributes
nothing to that operation, but requires time for entering the wire and getting
out of it again between every two consecutive signals just the same as though
it produced them. Charge, therefore, is not only useless to electrical tele-
graphy but detrimental and should be suppressed, and which I propose to do.
to a greater or lesser extent by the first part of this Invention.
The means by which it is to be carried into effect are deemed by public opinion
to be incapable of affording any good result, but I have practically confirmed
a different conclusion, first indicated by my own particular views of electricity
promulgated in 1851. Those means comprise for each telegraph the employ::
ment of two separate conductors placed concentrically one within the other,

page_text: the outer one for charge and the other for conduction; the former, being insu-
lated both. from the inner and all external conductors, is maintained in a
permanent state of charge, either positive or negative, which suppresses by
its induction the collection of a similar charge on the inner conductor on its
becoming placed for the transmission of signals in communication with a
voltaic battery at one of its ends, and with the earth at the other. Under
the circumstances mentioned, although the inner conductor would if tempo-
rarily insulated acquire from the battery an electrical intensity of action, the:
battery, so far as that conductor is concerned, will, when the latter is in com-.
munication with the earth, expend its intensity .wholly or in great part in
establishing conduction of electricity along it, and not in accumulating a large:
quantity upon it, for the conduction results from the intensity of the battery
in connection just as charge would do if its accumulation.were not resisted:
by the high intensity of induction from without inwards, and which is not.
opposed to conduction along the line of the central conductor.
The practical way of putting the first part of my Invention into operation:
will be understood from the following description:-A metallic wire or strand:
of wires of any ordinary size is to be closely surrounded in the usual way.
with gutta percha, put on in three or four thin coatings cemented together
and to the inclosed conductor by Stockholm tar thickened with gutta percha.
and resin, or other suitable insulator. The whole is then to be enveloped by.
a cylinder of small metallic wires, laid on longitudinally with a slight spiral,
in a bed of the same cement, against the outside of which is to be placed
another insulator of gutta percha put on in thin coatings and cemented as.
in the case of the inner insulator. Finally, the cable thus constructed may
be payed with tarred hemp or canvas, to afford it protection, and if neces-
sary covered with heavy wires to secure it from injury. The metals differ
from one another greatly in the quantities of electricity they can severally
conduct at one time, and superior specific conductivity is of importance when
charge has to be conducted in and out of a telegraph wire between every two
consecutive signals; but as I require only a small quantity of electricity to be
transmitted through the central conductor as a wave, and have not to wait for
a large quantity to collect upon it as a charge, that conductor may be made of
any of the cheap metals, the velocity with which either of them can conduct a
wave of electricity being at the rate of many thousands of miles in a second
of time. I therefore prefer, in consequence of its great tensile strength, to
construct the inner conductor of steel wire, say, one-eighth or one-sixth of an
inch in diameter, and when still greater tensile strength is wanted, to make
the outer conductor of steel wires also, they being larger or smaller in

page_text: diameter as the circumstances of each case may suggest. When very great:
strength is not required the outer conductor may be formed of a thin ribbon
of any flexible metal or alloy laid on longitudinally or wound spirally
around the inner insulator. Caoutchouc or any other suitable material may,
be substited for the gutta percha, and the cable may be protected in any.
approved manner instead of as described.
:
Whatever be the materials selected for the construction of the cable, and:
whether it be placed for use under water, buried in the earth, or left in the
atmosphere exposed or inclosed for its protection, it is to be prepared for use
and used in the following manner or in some other way equivalent to it :-A con-
venient length of the central conductor being made to project at each end into
the atmosphere beyond its insulator is to be connected at one of the working
stations with the sending voltaic battery and at the other station with the
earth through the receiving instrument. The outer insulator is to be cut
away at its two ends to allow the outer conductor being detached from
the inner insulator and placed with one or each of its ends permanently in
communication with the particular pole of a voltaic battery which corresponds
to that connected with the inner conductor. Under these arrangements
charge will assemble on the outer conductor, because it can there act
inductively both on the water, or earth, or other matter surrounding it on one
side and also on the uninsulated inner conductor in the other direction. The
intensity of its action in the two directions will be equal. To avoid ambiguity
I will suppose the charge to be positive or plus. In consequence of the
induction acting from without inwards some of the electricity naturally be-
longing to the central conductor will pass from it into the earth; on putting
the central conductor into momentary contact with its battery, electricity will
pass into it, because of the difference between the intensity of the battery and
the neutral condition of the earth between which it is interposed, but the
electricity which enters will not remain upon it, charge being opposed by the
induction inwards, which has already chased out some of the electricity that
naturally belonged to it. Nothing more is necessary but to actuate the sending
instrument in any usual way by hand or by mechanical appliances to transmit
a rapid succession of signals by the expenditure of a minimum quantity of
electricity, and consequently with a corresponding economy of time. I
recommend three batteries to be used, a separate one on the central conductor
and two of equal intensity on the outer conductor.
The second part of this Invention, which is for sinking light subaqueous
electrical cables, so as to recover them in case of need with greater facility
from the deepest seas is the more perfect, as the cables to be sunk

page_text: and recovered approximate in specific gravity to that of the water by which
they have to be surrounded, it is as follows:-A sufficient quantity of cast-
iron ballast is to be provided, each piece in the form of a half ring or semi-
cylinder, so modelled as to admit of being hinged or pinned together in
couples, so as to form a perfect ring or short pipe with two trumpet mouths,
and to fit very loosely on the cable around which the pieces are to be passed
and secured together in the act of paying it out. The pieces may be of any
convenient weight, and the interval between them on the cable regulated
from time to time to meet. the exigencies of submersion as they may arise.
The great advantage this part of the Invention offers is that a light cable, its
ends being free when lifted by one of them, or a bight after being so sunk,
will readily slip away from its ballast, and thus be recoverable by a compara-
tively small lifting power from the bottom of the deepest waters.
What I claim as my Invention is,
1stly, the suppression either wholly or in part of retarding charges on the
signalling conductors of electrical telegraphs by means of a second conductor
placed for that purpose around each of them and made to act inductively upon
it by possession of a permanent electrical charge of the same character as that
in use for supplying the signals.
2ndly, the use of moveable weights around subaqueous cables, for the
purpose described.
In witness whereof, I, the said Richard Laming, have hereunto set my
hand and seal, this Twenty-sixth day of February, in the year of our
Lord One thousand eight hundred and sixty-six.
RICHARD LAMING. (L.S.)