IMPROVEMENTS IN ELECTRIC TELEGRAPHS."
Year: 1872

page_text: LETTERS PATENT to Henry Highton, M.A., of Putney, in the
County of Surrey, for the Invention of "IMPROVEMENTS IN ELECTRIC
TELEGRAPHS."
PROVISIONAL SPECIFICATION left by the said Henry Highton at
the Office of the Commissioners of Patents, with his Petition, on
the 1st January 1872.
I, HENRY HIGHTON, M.A., of Putney, in the County of Surrey,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN ELECTRIC TELEGRAPHS," to be as follows:-
:-
The object of my Invention is to communicate by means of unin-
sulated or very imperfectly insulated wires. I prefer such an amount of
insulation as shall prevent the corrosion of the wires if underground or
under the water, and metallic contact if more wires than one are used
but not sufficiently perfect to produce much induction of the Leyden
jar kind.

page_text: Sometimes I use a circuit wholly metallic and employ that part of
the current which passes wholly through the metallic circuit for making
the required signals.
If the earth be used for the return current the connection with the
earth at the receiving end should be made to offer as small a resistance 5
as possible. This may be done by increasing the size of the electrode in
contact with earth and by placing it in a solution which shall facilitate
the passage of as large a portion as possible of the current by that
electrode. It is best to heat this solution. The instrument for receiving
the signals should be one which is at once as sensitive as possible and 1
cause as little resistance as possible to the current.
I prefer a gold leaf galvanoscope, as described in my Patent of
February 3rd, 1846, with a powerful permanent or electro-magnet; the
apparent motion may be increased by optical means, such as a concave
mirror, microscopic or telescopic lenses, or an arrangement for throwing 1
a magnified representation on a screen, as in a magic lantern.
The signals may be registered photographically on a slip of paper
moved by clockwork or otherwise by means of a powerful artificial light
throwing the shadow or reflection of the gold leaf through a hole or slit.
Or I employ a galvanometer formed with very thick and long wire
enveloping a sheet of very thin soft iron.
The receiving galvanoscope may be kept at zero when signals are not
passing, by means of a battery the strength of the current from which
may be varied at discretion, which is placed in a loop line and works
through the galvanoscope.
The battery employed for long distances should be one very powerful

page_text: may conveniently be about 1 inch and a half and its breadth about 1/10th
of an inch, the leaf should be the thinnest that can be obtained. The
leaf is protected by flat glasses. I prefer to make a case of four strips
of glass cemented together with Canada balsam. I find a very con-
venient size of the case to be about half an inch wide from back to front,
and about one inch from side to side, so as to allow for a freedom of
motion of the gold leaf in that direction. Close to the glass at the back
or front or both and about midway of the length of the gold leaf I
place one or both poles of a powerful magnet. I prefer an electro-
magnet. The gold leaf being thus situated in an intense magnetic field
is moved even when a very feeble current is sent through it. A stream
of light is thrown upon the gold leaf by means of a lamp and
condensing lens, and by means of another lens an enlarged image of
the gold leaf is thrown upon a screen at a distance of some feet. The
magnified image will be very casily observed even when the motion
of the gold leaf is too small to be otherwise appreciable. Or, the
image of a small horizontal section of the gold leaf may be caused to
fall through a horizontal slit upon a strip of photographic paper placed
in a dark chamber, to which strip a continuous motion is given by
clockwork. In this case the action of the light on the photographically
prepared paper will cause the successive positions of the horizontal
section of the gold leaf to become recorded upon the paper. The
horizontal slit should be so placed in reference to the gold leaf as to
admit the shadow of that part of the gold leaf where the motion is
greatest, that is usually a little below the centre of it.
The magnet is in such a form and in such a position as not to
interfere with the passage of the light to and from the gold leaf, or at
least some part of it, and should be so placed as to cause the gold leaf to
move in a plane perpendicular to the direction of the beam of light.
..:
The great advantage which this instrument has over all others when
combined with a line in which the insulation is defective, arises not only
from the great sensitiveness of the instrument but also from the small
amount of resistance which it offers to the passage of the telegraphic
current. Feeble currents of low intensity are able to traverse the gold
leaf and can be appreciated, whereas by an instrument offering a large
resistance such currents would be almost completely arrested, and in the
' division of the current between the instrument and the faults in the line

page_text: a smaller portion is lost at the faults and a larger portion traverses the
instrument than where instruments of a larger resistance are used.
What I claim is, the combination of apparatus for telegraphing or
signalling by means of electricity, substantially as described.
In witness whereof, I, the said Henry Highton, have hereunto set
my hand and seal, this Twenty-ninth day of June, in the year of
our Lord One thousand eight hundred and seventy-two.
H. HIGHTON. (L.S.)