AN IMPROVED MODE OF PROTECTING TORPEDOES FROM PREMATURE EXPLOSION."
Year: 1874

page_text: LETTERS PATENT to James Mathieson, of West Ham, in the County of
Essex, Electrician, for the Invention of "AN IMPROVED MODE OF
PROTECTING TORPEDOES FROM PREMATURE EXPLOSION."
PROVISIONAL SPECIFICATION left by the said James Mathieson at
the Office of the Commissioners of Patents, with his Petition, on
the 19th January 1874.
I, JAMES MATHIESON, of West Ham, in the County of Essex,
Electrician, do hereby declare the nature of the said Invention for
"AN IMPROVED MODE OF PROTECTING TORPEDOES FROM PREMATURE EXPLOSION,"
to be as follows:-
:-
My Invention relates to that class of torpedoes which discharges on
being struck by a passing vessel, the ignition being caused by the sudden
release of an exciting fluid, or by friction, or by a blow, as is well under-
stood. In torpedoes of this class it is usual to secure the exploding bolt,
hammer, or equivalent mechanical contrivance by which the torpedoc is

page_text: being handled for the purpose of mooring by means of a cap, plug, pin, or
equivalent device, and thereby to prevent accidental or premature
explosion. As however it is necessary to withdraw this locking device
to enable the torpedoe to act, the workmen engaged in the operation are
subject to great risks, and it is to provide against such risks that my
Invention is directed. To attain this end I make the locking or guard
contrivance of a composition or cement that is soluble in water. Thus
instead of having to remove the guard by hand, as at present, I rely
upon the slow action of the water to destroy the consistency of the
cement, and thereby leave the firing device free to act.
In applying my Invention for example to a torpedoe which is to be
ignited by the breaking of a glass tube, and by the release of sulphuric
acid therefrom, I sustain by means of a disc of soluble cement the
hollow leaden spindle which surrounds the tube and carries a weight for
bending the tube when the torpedoe is struck by a passing vessel and
thereby breaking the glass vessel. This disc I drop over the leaden
spindle and provide a recess to receive it and hold it firmly. Over this
I place a metal cap which will cover the weighted end of the spindle
and protect the disc from the action of the water. When the torpedoc
is properly moored the metal cap is to be removed, and not until the
water is dissolved the disc can the mechanical primer be put in action;
this will permit of the workmen getting far from dangor before the
torpedoe is ready for action.
It will be obvious that a plug may be used in place of a disc in other
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Mathieson in the Great Seal Patent Office
on the 18th July 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
MATHIESON, of West Ham, in the County of Essex, Electrician, send a
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of January, in the
year of our Lord One thousand eight hundred and seventy-four, in the

page_text: thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said James Mathieson, Her special
licence that I, the said James Mathieson, my executors, administrators,
and assigns, or such others as I, the said James Mathieson, 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, usc,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for “AN
IMPROVED MODE OF PROTECTING TORPEDOES FROM PREMATURE EXPLOSION," upon
the condition (amongst others) that I, the said James Mathieson, 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 James Mathieson, do hereby declare
the nature of my said Invention, and in what manner the samo is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto
annexed and to the letters and figures marked thereon (that is to
say) :-
My Invention relates to that class of torpedoes which discharge on
being struck by a passing vessel, the ignition being caused by the sudden
release of an exciting fluid, or by friction, or by a blow, as is well under-
stood. In torpedoes of this class it is usual to secure the exploding bolt,
hammer, or equivalent mechanical contrivance while the torpedo is
being handled for the purpose of mooring by means of a cap, plug, or
equivalent device, and thereby to prevent accidental or premature
explosion. As however it is necessary to withdraw this locking device
to enable the torpedo to act, the workmen engaged in the operation aro
subject to great risks, and it is to provide against such risks that my
Invention is directed. To attain this end I make the locking or guard
contrivance of a composition or cement that is soluble in water. Thus
instead of having to remove the guard by hand, as at present, I rely
upon the slow action of the water to destroy the consistency of the
cement and thereby leave the firing device free to act.

page_text: In applying my Invention for example to a torpedo which is to be
ignited by the breaking of a glass tube and the consequent release of
sulphuric acid therefrom, I sustain by means of a disc of soluble cement
the hollow leaden spindle which surrounds and protects (while its shape
is maintained) the glass tube.
The application of my Invention to this class of torpedo is illustrated
in sectional elevation at Fig. 1 of the accompanying Drawing. In this
Figure a is the glass tube containing the sulphuric acid; b, a hollow leaden
spindle surrounding it, and carrying at its upper end a rod c which is
intended to receive a spherical weight d, which weight when suddenly
set in vibration will cause the leaden spindle to bend and break the glass
tube which it surrounds. e is a cap which fits over the weighted end
of the rod c and serves to maintain it in line with the tube a, so long
therefore as this cap or locking device is in place the torpedo will be
protected from exploding. f is an india-rubber tube which serves to
give an elastic support to the weighted rod c; g is a collar formed with
a flange on which the cap e is fitted, and this collar is further provided
with an internal flange on which rests a disc / constituting my improved
soluble guard. This disc forms a packing between the weighted rod c
and the collar g, and it will therefore effectually prevent the vibration of
this rod so long as the disc retains its consistency. As the disc is covered
by the cap e during the operation of mooring the torpedo the water will be
prevented from reaching and attacking the disc. I may find it con-
venient to fit the torpedo with an india-rubber cap or cover i which will
yield to allow of the metal cap e being withdrawn, and will then close
and prevent the access of marine animals to or accumulation of
extraneous substances in the cup K of the torpedo. Provision is made
for the access of water to the cup for the purpose of dissolving the
disc.h.
As the construction and action of this kind of torpedo is well under-
stood it will be unnecessary to describe it further in detail, but it will
suffice to remark that when the torpedo is properly moored the metal
cap is to be removed by a hauling line and the water will then prepare
tho torpedo for firing. When sufficiont time has been allowed for the
water to dissolve the disc the mechanical primer will be free to act in
answer to the blow imparted to the torpedo by a passing vessel. Ample
time however will be allowed for the workmen engaged in mooring the
torpedo, getting far from danger before it is ready for action.

page_text: Figures 2 and 3 illustrate the application of my Invention to a torpedo
which is fired by the withdrawal of a bolt; Fig. 2 being a side view of
the torpedo; and Fig. 3 an enlarged view of the parts connected with
the firing bolt. is the mooring eye, and to its stem is fitted a lug mf or
receiving freely through it an eyebolt n to which the firing chain is
attached. This chain is divided into two parts o and o¹, the former of
which connects with a loose cover or weight p that rests on the top of
the torpedo, while the latter connects with the firing plug g of the
torpedo. The eyebolt n is held in place and caused to sustain the chain
in the position shewn in Fig. 2 by means of a plug or disc of soluble
cement to which it is attached, and which rests upon the lug m. This
connection of the eyebolt and plug or disc is made sufficiently secure to
enable the cyebolt to resist any accidental pull of the weighted end of
the chain. When however the torpedo has been moored for a sufficient
time to enable the surrounding water to dissolve the plug or disc r the
eyebolt will drop out of place, and the chain will assume the dotted
position of Fig. 2. If therefore the torpedo is now struck by a passing
vessel the weight or cover p will be dislodged and caused to put a sudden
drag on the chain, the result of which will be the withdrawal of the
firing plug q and the explosion of the torpedo.
I would remark that I do not limit myself to the use of any special
materials in the manufacture of the composition or cement which I
employ in carrying out my Invention, but what I have found to answer
well in practice and therefore propose in general to use is a mixture of
sugar and chalk, which when hard will have considerable resisting
power, and when submitted to the action of water will readily dissolve.
The proportions which I prefer aro three parts of sugar to ono of chalk.
The chalk I reduce to powder and mix it gradually with the sugar while
the latter is reduced to a fluid state by the application of heat. The
thickness of the disc or plug employed will depend upon the mechanical
resistance it is intended to offer, and the duration of its resistance to the
action of the water may be reduced by increasing the proportion of
chalk in the mixture.
Having now set forth the nature of my Invention of "An Improved
Mode of Protecting Torpedoes from Premature Explosion," and explained
the manner of carrying the same into effect, I wish it to be understood
that under the above in part recited Letters Patent I claim, the appli-
cation to torpedoes of a soluble composition or cement to act as a guard

page_text: or locking device, in the manner and for the purpose above set
forth.
of our
In witness whereof, I, the said James Mathieson, have hereunto
set my hand and seal, the 17th day of July, in the
year
Lord One thousand eight hundred and seventy-four.
JAMES MATHIESON. (L.s.)