AN IMPROVED SUB- MARINE TELEGRAPHIC CABLE
Year: 1879

page_text: LETTERS PATENT to Auguste Blondot and Jules Bourdin, of Boulevard Saint
Denis, No. 1, at Paris, Engineers, for the Invention of "AN IMPROVED SUB-
MARINE TELEGRAPHIC CABLE."
Sealed the 27th December 1879, and dated the 30th June 1879.
PROVISIONAL SPECIFICATION left by the said Auguste Blondot and Jules
Bourdin at the Office of the Commissioners of Patents on the 80th June 1879.
AUGUSTE BLONDOT and JULES BOURDIN, of Boulevard Saint Denis, No. 1, at
Paris, Engineers. "AN IMPROVED SUBMARINE TELEGRAPHIC CABLE."
Our improved submarine telegraphic cable is composed of a single copper con-
ductor covered with several insulating coatings. The first of these, that in contact
with the conductors, is of gutta percha, the second is of caoutchouc, the third of
gutta percha, the fourth of caoutchouc, and the fifth of gutta percha, mineralised
by a mercurial salt. The cable is further surrounded by a covering of tarred
hemp.
The density of our cable is lower than 17, except at the ends, which have a
metallic covering like ordinary cables.
The soldering or uniting of the conductor is effected as follows:-The two ends
to be united are bevelled and soldered with silver solder; a piece of copper tube
without solder covers the bevels, and extends about half an inch beyond them. A
little silver solder is run into the tube for its whole length so as to compensate for
the weakness caused by the non-continuity of the conductor.
The covering tube is thinned externally at its ends in order to avoid creating a
point of resistance to flexion, and to facilitate the laying of the insulating
covering.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Auguste Blondot and Jules Bourdin in the Great Seal Patent
Office on the 30th December 1879.
AUGUSTE BLONDOT and JULES BOURDIN, of Boulevard Saint Denis, No. 1, at
Paris, Engineers. "AN IMPROVED SUBMARINE TELEGRAPHIC CABLE."
Our improved submarine telegraphic cable is composed, as shewn on the accom-
panying Drawing (shewn to double the natural size), of a single copper conductor c
covered with several insulating coatings. The first a of these, that in contact with
the conductor, is of gutta percha, the second b is of caoutchouc, the third a¹ of
gutta percha, the fourth 61 of caoutchouc, and the fifth all of gutta percha
mineralised by a mercurial salt. The cable is further surrounded by a covering g of
tarred hemp.
The density of our cable is lower than 17, except at the ends, which have a
metallic covering like ordinary cables.
The soldering or uniting of the conductor is effected as follows:-The two.
ends a', c, to be united are bevilled and soldered with silver solder; a piece of
copper tube d without solder covers the bevels, and extends about half an inch
beyond them.
A little silver solder is run into the tube for its whole length so as to compensate
for the weakness caused by the non-continuity of the conductor. The covering
tube is thinned externally at its ends in order to avoid creating in h and n a point
of least resistance to its flexion, and to facilitate the laying of the insulating
covering.
Although the Drawing is made to double the natural size the dimensions may
remain unaltered, since they depend on the indicated depths of the soundings.
In witness whereof, we, the said Auguste Blondot and Jules Bourdin, have
hereunto set our hands and seals, this Twenty second day of December, in
the year of our Lord One thousand eight hundred and seventy nine.
ALATE BLONDOT
Witness,
ALBERT CAHEN,
Civil Engineer,
of Boulevard Saint Denis, 1,
Paris.
AUGTE BLONDOT. (LS)
J. BOURDIN.
(LS)