IM- PROVEMENTS IN FOG AND OTHER SIGNALS."
Year: 1871

page_text: LETTERS PATENT to John Richardson Wigham, of Albany House,
Monkstown, in the County of Dublin, for the Invention of "IM-
PROVEMENTS IN FOG AND OTHER SIGNALS."
PROVISIONAL SPECIFICATION left by the said John Richardson
Wigham at the Office of the Commissioners of Patents, with his
Petition, on the 9th December 1871.
I, JOHN RICHARDSON WIGHAM, of Albany House, Monkstown, in the
County of Dublin, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN FOG AND OTHER SIGNALS," to be as follows:-
My Invention consists in making fog and other signals by the explosion
of combustible gases instead of by explosion of gunpowder, gun cotton,
or other explosive material heretofore used.
This object is effected by exploding the gases in guns, or exploding
tubes, or chambers provided with valves for the purpose of charging

page_text: them with the explosive gases, and for effecting the ignition thereof.
These explosion chambers are charged by admitting the gases for
explosion under any suitable pressure from receptacles containing them
through valves adjusted so as to let them pass in the required pro-
portions.
The gas may be fired or exploded by percussion or by ignition with
or without the application of machinery for that purpose. The firing of
the gases by ignition is either effected by a jet of gas or other flame kept
burning near the touch-hole of the explosion chamber, which is provided
with a small valve. On opening this valve the flame ignites the contents
of the chamber. The valve may be opened at regulated periods by the
action of ordinary clockwork connected to it; or the ignition may be
effected by an electric spark produced at the required intervals in any
suitable known manner by means of a galvanic battery or electro-
magnetic apparatus of known construction.
The result to be obtained is the production of loud reports or
explosions for fog signal purposes, or for any other signalling purpose
requiring loud sounds, or reports, or explosions similar to those caused
by the explosion of gunpowder in ordinary cannons, saluting chambers,
mortars, or other similar implements.
It may be readily understood that in clear weather the flash of the
explosion will also serve for signalling purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Richardson Wigham in the Great Seal Patent
Office on the 7th June 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
RICHARDSON WIGHAM, of Albany House, Monkstown, in the County of
Dublin, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of December, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Richardson Wigham, Her

page_text: special licence that I, the said John Richardson Wigham, my
executors, administrators, and assigns, or such others as I, the said
John Richardson Wigham, 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 FOG AND OTHER SIGNALS," upon
the condition (amongst others) that I, the said John Richardson
Wigham, 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 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 John Richardson Wigham, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, reference being had to the accom-
panying Sheet of Drawings and to the figures and letters marked
thereon, that is to say :-
My Invention consists in making fog or other signals by the explosion
of combustible gases instead of by explosions of gunpowder, gun cotton,
or other explosive material heretofore used.
This object is effected by exploding the gases in one or more guns, or
exploding tubes, or chambers, or mitraileuse combination of such tubes
or chambers, provided with valves, or cocks, or gas holders for the
purpose of charging them with the explosive gases, and with suitable
means for igniting these gases when the explosion chambers are so
charged. These explosion chambers are charged by admitting the gases
for explosion under any suitable pressure from receptacles containing
them through valves or cocks so as to let them pass in the required
proportions.
The gases may be fired or exploded by percussion or by ignition with
or without the application of machinery for that purpose. The firing of
the gases by ignition is either effected by a jet of gas or other flame kept
burning near the touch-hole of the explosion chamber, which is provided

page_text: with a small valve. On opening this valve the flame ignites the contents
of the chamber. The valve may be opened at regulated periods by the
action of ordinary clockwork connected to it; or the ignition may be
effected by an electric spark produced at the required intervals in any
suitable known manner by means of a galvanic battery or electro-
magnetic apparatus of known construction; or the ignition may be
effected by percussion caps, friction tubes, or any simple application of
a flame or white hot surface to the mixed gases either at the touch-hole
or muzzle of the explosion chamber.
The result to be obtained is the production of loud reports or
explosions for fog signal purposes, or for any other signalling purpose
requiring loud sounds, or reports, or explosions similar to those caused
by the explosion of gunpowder in ordinary guns, cannons, saluting
chambers, mortars, or other similar implements.
It may readily be understood that the flash of the explosion will also
serve for signalling purposes.
The accompanying Drawing snews one arrangement by which my
before-described Invention may be carried into practice.
A is the explosion chamber or gun into which the combustible gases
are admitted at regulated intervals and in the required proportions for
forming an explosive compound from the gas holders B, B'. For this
purpose pipes b, b', conduct the gases from the gas holders to a mixing
chamber e, the admission of the gases at the desired intervals and in
the proper proportions into this chamber being regulated by cocks or
valves c, c', which are opened and closed at the desired intervals either
by hand or by any suitable known arrangement of clockwork mechanism.
From the mixing chamber the gases pass through the pipe e¹ into the
explosion chamber A.
For preventing the escape of the gases from the muzzle of the gun
before the charge is fired, a flap valve may be provided at the muzzle
provided with a spring or weight so that the valve will readily open when
the explosion is effected, and will then close it itself.
The chamber or gun A being charged and the cocks c, c¹, closed, a
cock or valve d on the touch-hole of the gun is opened, and a moveable

page_text: igniting arm f with gas jet is made to convey a small flame from the
shaded lamp g to the touch-hole, whereby the charge in the gun is
ignited. The opening and closing of the cock d, as also the motion of
the igniting arm f, may be effected automatically by the same clockwork
mechanism that actuates the cocks c, c¹.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I wish it to be understood that I
do not limit myself to the arrangement of apparatus for carrying the
same into effect, as shewn on the accompanying Drawing, as it will be
evident that various other arrangements may be employed for this
purpose, as has been herein-before described; but what I claim is,
making fog or other signals by the explosion of charges of combustible
gases introduced into one or more explosion chambers or guns, sub-
stantially as herein-before set forth.
In witness whereof, I, the said John Richardson Wigham, have
hereunto set my hand and seal, this Third day of June, in the
year of our Lord One thousand eight hundred and seventy-two.