IMPROVEMENTS IN ELECTRIC TELEGRAPH CABLES
Year: 1868

page_text: LETTERS PATENT to Thomas Jefferson Mayall, of Roxbury, Massa-
chusetts, United States of America, now of No. 8, Southampton
Buildings, Chancery Lane, in the County of Middlesex, for the
Invention of "IMPROVEMENTS IN ELECTRIC TELEGRAPH CABLES."
Sealed the 5th January 1869, and dated the 8th July 1868.
PROVISIONAL SPECIFICATION left by the said Thomas Jefferson Mayali
at the Office of the Commissioners of Patents, with his Petition;
on the 8th July 1868.
I, THOMAS JEFFERSON MAYALL, of Roxbury, Massachusetts, United
States of America, now of No. 8, Southampton Buildings, Chancery
Lane, in the County of Middlesex, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN ELECTRIC TELEGRAPH CABLES," to be as
follows:--
The nature of my Invention consists chiefly,-
First. In the method of encasing the conducting wires of the cable
with insulating compounds and materials:

page_text: Second. In the application to such cables of an exterior casing of
vulcanized india-rubber, gutta percha, or a combination of both sub-
stances.
And, third. In a novel compound or combination of india-rubber and
gutta percha with other ingredients to form the exterior casing.
The conducting wire or wires of the cable may be of any ordinary
kind and arrangement. I coat or cover these wires in the usual manner
with india-rubber or gutta percha, or both substances combined, or
compounds of the same with other materials, and I then apply to the
exterior of this coating a wrapper of cloth or woven fabric covered, or
what is technically termed " frictioned," on both sides with a solution
of the same substance or compound. In this condition the cable will
serve for all ordinary purposes as a land telegraph cable; but for use
under some circumstances it may require additional protection, which
is secured by the application of the improved protective covering over
the cloth wrapper, which is prepared in the following manner :-Upon
a sheet of cotton or other fabric I spread a layer of pure rubber dissolved
with camphine or other solvent. Over this rubber I apply the vul-
canizing substance or compound, which is then cured or vulcanized in
the ordinary manner. I prefer to use for this purpose a compound
composed of the following ingredients in about the proportions named:-
I take one pound of Para rubber, one pound of gutta percha, one pound
of zinc, two pounds of pipeclay, one quarter of a pound of sulphur, and
one half pound of shellac, one half pound of French chalk, and two
ounces of white resin. This compound should be cured or vulcanized
for about two and one half hours at a temperature of about two hundred
and fifty degrees Fahrenheit; but these proportions, as well as the
number of hours and degrees of heat, may be slightly varied without
affecting the result. The cloth or fabric is then removed from the
vulcanizing sheet, its removal being easily effected by wetting the same
with hot water, camphine, or naptha, and peeling it from the said sheet.
The vulcanized sheet, either before or after the removal of the cloth, is
divided into strips of the proper size to suit the diameter of the cable,
and is wrapped over the same. The surface of the rubber from which
the cloth is taken is adhesive, and the overlapping ends are thoroughly
secured and made water-tight.
When my improved cable is to be used for a submarine or ocean
telegraph it will be necessary to strengthen the same by the use of wire

page_text: rope or plaited or twisted fibrous materials or other substance ordinarily
employed in the construction of such cables. Over this wire or other
strengthening material I apply my improved protective covering, as
above described, the cable being then ready for use.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Jefferson Mayall in the Great Seal Patent
Office on the 8th January 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
JEFFERSON MAYALL, of Roxbury, Massachusetts, United States of
America, now of No. 8, Southampton Buildings, Chancery Lane, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of July, in the year of our
Lord One thousand eight hundred and sixty-eight, in the thirty-second
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Thomas Jefferson Mayall, Her special licence
that I, the said Thomas Jefferson Mayall, my executors, administrators,
and assigns, or such others as I, the said Thomas Jefferson Mayall,
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 TELEGRAPH CABLES," upon the condition (amongst others) that
I, the said Thomas Jefferson Mayall, 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 per-
formed, 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 YB, that I, the said Thomas Jefferson Mayall, do hereby
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 :-

page_text: The nature of my Invention consists chiefly,-
First. In the method of encasing the conducting wires of the cable
with insulating compounds and materials.
Second. In the application to such cables of an exterior. casing of
vulcanized india-rubber, gutta percha, or a combination of both
substances.
And, third. In a novel compound or combination of india-rubber and
gutta percha with other ingredients to form the exterior casing.
The conducting wire or wires of the cable may be of any ordinary
kind and arrangement. I coat or cover these wires in the usual manner
with india-rubber or gutta percha, or both substances combined, or
compounds of the same with other materials, and I then apply to the
exterior of this coating a wrapper of cloth or woven fabric covered, or
what is technically termed "frictioned," on both sides with a solution
of the same substance or compound. In this condition the cable will
serve for all ordinary purposes as a land telegraph cable; but for use
under some circumstances it may require additional protection, which
is secured by the application of the improved protective covering over
the cloth wrapper, which is prepared in the following manner :-Upon
EL sheet of cotton or other fabric I spread a layer of pure rubber dissolved
with camphine or other solvent. Over this rubber I apply the vulcanizing
substance or compound, which is then cured or vulcanized in the
ordinary manner. I prefer to use for this purpose a compound composed
of the following ingredients in about the proportions named:-I take one
pound of Para 'rubber, one pound of gutta percha, one pound of zinc,
two pounds of pipeclay, one quarter of a pound of sulphur, one half
pound of shellac, one half pound of French chalk, and two ounces
of white resin. This compound should be cured or vulcanized for about
two and one half hours, at a temperature of about two hundred and fifty
degrees Fahrenheit; but these proportions, as well as the number of
hours and degrees of heat, may be slightly varied without affecting the
result. The cloth or fabric is then removed from the vulcanizing sheet,
its removal being easily effected by wetting the same with hot water,
camphine, or naphtha, and peeling it from the said sheet. The vulcanized
sheet, either before or after the removal of the cloth, is divided into
strips of the proper size to suit the diameter of the cable, and is wrapped
over the same. The surface of the rubber from which the cloth is taken

page_text: is adhesive, and the overlapping ends are thoroughly secured and made
water-tight.
When my improved cable is to be used for a submarine or ocean
telegraph, it will be necessary to strengthen the same by the use of wire
rope, or plaited or twisted fibrous materials, or other substance ordinarily
employed in the construction of such cables. Over this wire or other
strengthening material I apply my improved protective covering, as
above described, the cable then being ready for use.
Having thus fully described my said Invention, and shewn how
the same may be conveniently and advantageously carried into practice,
I claim,―
First. Encasing the conducting wires of the cable with insulating
materials and compounds, substantially as set forth.
Second. Applying to the cable an exterior casing of vulcanized
india-rubber, gutta percha, or of both combined.
Third. The compound for forming the said exterior casing, con-
sisting of the herein specified ingredients combined in the proportions
(or nearly in the proportions) given, and treated substantially as set
forth.
In witness whereof, I, the said Thomas Jefferson Mayall, have
hereunto set my hand and seal, this Fourth day of January,
in the year of our Lord One thousand eight hundred and sixty-
nine