IMPROVED MEANS AND APPARATUS FOR SIGNALLING BY DIVERS UNDER WATER
Year: 1876

page_text: LETTERS PATENT to Pryse Protheroe, of Surbiton, in the County of Surrey, for
the Invention of "IMPROVED MEANS AND APPARATUS FOR SIGNALLING BY DIVERS
UNDER WATER."
Sealed the 22nd August 1876, and dated the 12th June 1876.
PROVISIONAL SPECIFICATION left by the said Pryse Protheroe at the Office
of the Commissioners of Patents on the 12th June 1876.
PRYSE PROTHEROE, of Surbiton, in the County of Surrey.
AND APPARATUS FOR SIGNALLING BY DIVERS UNDER WATER."
"IMPROVED MEANS
My Invention relates to means and apparatus whereby a diver or person operating
under water can conveniently signal by electricity to persons above.
For this purpose I provide a battery or other source of electrical power, one pole
of which I connect to the water and the other to a signalling instrument of ordinary
construction, either for giving visible signals by the movement of an index or audible
signals by the sound of a bell, or it might be a writing instrument. I connect this
signalling instrument by an insulated conducting wire extending down the core of
or intertwined with a cord leading to a contact making apparatus within reach of
the hand of the person who has to signal.
This contact apparatus consists of a piece of water-tight tube or casing containing
the terminal of the conducting wire, which is kept by a spring out of contact with
another terminal that is in electrical communication with the water. Through holes
in the side of the tube or casing passes a sliding piece projecting somewhat beyond
the casing so as to present a knob on each side, and this sliding piece is attached to
one of the spring contact pieces within the tube or casing. Over the tube or casing
and the knob ends of the sliding piece is drawn a piece of caoutchouc or other water-
tight and pliable material. The water pressure acting equally on each end of the
sliding piece has no effect in moving it. When it is desired to signal the person
holding the contact apparatus in his hand presses the projection formed by the knob
end of the sliding piece and thus makes contact, whereby a current of electricity is
permitted to pass from the one pole of the battery through the signalling instrument
and contact apparatus to the water and thence back to the other pole of the
battery.
A signal is thus presented on the instrument above, and such signals may be
arranged according to any desired code, dependent on variations in the periods
Price fid

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Pryse Protheroe in the Great Seal Patent Office on the 4th December
1876.
PRYSE PROTHEROE, of Surbiton, in the County of Surrey.
AND APPARATUS FOR SIGNALLING BY DIVERS UNDER WATER."
"IMPROVED MEANS
My Invention relates to means and apparatus whereby a diver or person operating
under water can conveniently signal by electricity to persons above.
For this purpose I provide a battery or other source of electrical power, one pole
of which I connect to the water and the other to a signalling instrument of ordinary
construction, either for giving visible signals by the movement of an index or audible
signals by the sound of a bell, or it might be a writing instrument. I connect this
signalling instrument by an insulated conducting wire extending down the core of
or intertwined with a cord leading to a contact making apparatus within reach of the
hand of the person who has to signal.
The accompanying Drawing represents a vertical section of this contact making
apparatus, which is so arranged according to my Invention as to be insulated,
notwithstanding its immersion in water, and to remain undisturbed by change of
pressure according as the diver is at less or greater depth.
Referring to the Drawing, A is a portion of the cord or rope extending down to
the diver, having enclosed in it or intertwined with it two insulated conducting
wires B and C. These wires terminate in springs D and E having on them contact
faces & and e, which may be platinised in the usual manner. The ends of the springs
D and E engage in a recess in a sliding piece of vulcanite or other non-conducting
material F, both ends of which project through the sides of a tube G in which the
spring contacts are inclosed. Over the tube G is fixed an external tube H of caout-
chouc or other flexible waterproof fabric which covers the ends of the sliding piece
F. In the ordinary or normal position of the springs the two contact faces d and e
remain apart, so that no clectricity can pass from the one of the two wires B and C
to the other. But when the diver by pressing with his finger or thumb on either of
the projecting ends of the slide F pushes either of the springs D and E towards
the other then the two faces d, e, are brought into contact and an electrical circuit
through the wires B and C is completed. By the pressure of the water the outer
tube H will be more or less collapsed, but as the pressure acts equally on both ends
of the slide F no contact will be made except when it is pressed in either direction
by hand.
By maintaining contact for a shorter or longer time signals of the ordinary Morse
character, distinguished by dots and dashes or signals, according to other codes of
like character, can be readily transmitted.. It is obvious that by leading one of the
wires B or C into the water and connecting one of the battery poles to the water,
the other pole being connected to the wire that is retained, one of these wires might
be dispensed with, the circuit being completed through the water. I prefer, how-
ever, to retain both wires as I can thus generally get more distinct signals with
moderate battery power. The tube H has a cord attached to it by the ring I,
which cord is secured round the body or under the arms of the diver so that he is
not obliged to continually hold the instrument, and can thus use both hands for his
work.
Having thus described the nature of my Invention, and in what manner the same
is to be performed, I claim―
First. The method, substantially as herein-described, of transmitting signals from
divers by their making contact for electrical conductors by means of insulated con-
tact apparatus submerged along with them.

page_text: Second. The use for the purpose above referred to of a contact apparatus in which
springs that can be brought together by pressure on a prominent knob are arranged
within a flexible water-tight casing, the hydrostatic pressure on the knobs being
balanced substantially as herein described.
In witness whereof, I, the said Pryse Protheroe, have hereunto set my hand
and seal, this Sixth day of November, in the year of our Lord One thousand
eight hundred and seventy-six.
PRYSE PROTHEROE. (LS.)