A NEW SAFETY FUZE
Year: 1846

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
GEORGE SMITH, of Tuckingmill, Camborne, in the County of Cornwall,
Safety Fuze Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Twelfth day of November, in the tenth year of
Her reign, did give and grant unto me, the said George Smith, my
exors, adñiors, and assigns, Her special licence, full power, sole
privilege and authority, that I, the said George Smith, my cxors,
adiñors, and assigns, and such others as I, the said George Smith, my
exors, adiñiors, or assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term of
therein nientioned, should and lawfully might use, exercise, and vend
my Invention of "A NEW SAFETY FUZE," within that part of the
United Kingdom of Great Britain and Ireland called England, the
Dominion of Wales, and the Town of Berwick upon Tweed, and in
the Islands of Guernsey, Jersey, Alderney, Sark, and Man, and also
in. all Her said Majesty's Colonies and Plantations abroad, in such
manner as to me, my exors, admiors, or assigns, should seem meet; in
years

page_text: which said Letters Patent their is, amongst others, contained a proviso,
that if I, the said George Smith, should not particularly described and
ascertain the nature of my said Invention, and in what manner the
same is to be performed, by an instrument in writing under my hand
and seal, and cause the same to be enrolled in Her said Majesty's
High Court of Chancery within six calendar months next and in-
mediately after the date of the said recited Letters Patent, that then
the said Letters Patent, and all liberties and advantages whatsoever
thereby granted, should utterly cease, determine, and become void, as
by the said Letters Patent, reference being thereunto had, will more
fully and at large appear.
NOW KNOW YE, that in compliance with the said recited proviso,
I, the said George Smith do hereby declare the nature of my said
Invention, and in what manner the same is to be performed, to be
particularly described and ascertained in and by these Presents, and the
Drawings hereto annexed and herein referred to.
My Invention consists in the manufacture of a new safety fuze,
which shall not be injuriously affected by the changes of atmospheric
temperature in different climates, or by exposure to damp, or by the
action of water, or by the pressure to which it may be subjected
in sub-marine operations. For this purpose I employ gutta percha to
inclose an interior cylinder of gunpowder, or as a coating or covering
for gunpowder, contained in yarns, tape, threads, or other suitable
material, as has long been and is now the case in the ordinary safety
fuze. Firstly, for the manufacture of the new safety fuze, which is to
consist of a cylinder or column of gunpowder in a coating of gutta
percha, I proceed as follows:-I employ an apparatus shewn in Figure
1. A, is a chamber or vessel in which the gutta percha is placed.
This is made cylindrical from the top to the joint (a), the space
through which the piston traverses. From the joint (a) it tapers
downwards in the form of an inverted cone (E, E,) until it terminates
at the hole (c), which is continued through a pipe to (F). This
chamber is made of any suitable metal of sufficient strength to bear a
pressure of about five hundred pounds to the square inch, and it is
about eight or ten inches deep from (a, a,) upwards. For the manu-

page_text: facture of a single fuze the interior of this chamber may be from five
inches to six inches in diameter, or the upper part above the joint (a)
may be made square or oblong of any given size, and it may have
several inverted conical pieces, each furnished with a powder chamber,
herein-after mentioned, screwed to its lower edge, and thus at the same
time several separate safety fuses may be made. B, is the powder
chamber or funnel. This is also cylindrical from the top to the place
(a, a), from whence it tapers to a point, entering into the interior of
the pipe before spoken of at the orifice (c), leaving an opening for the
escape of a small stream of gunpowder into the centre of the fuze.
This chamber or funnel is supported and kept in an upright position
by four thin pieces of metal firmly secured by soldering, riveting, or
otherwise to the outside of the powder chamber and to the inside of
the gutta percha chamber; two of these pieces of metal are shewn
M, M; these effect the purpose intended without preventing the gutta
percha from being pressed down into the aperture c, of the pipe below.
C, is the steam chamber formed around the gutta percha chamber; it
entirely encloses the vessel or chamber containing the gutta percha,
and is formed with a thin metallic case (k,,) extending from the joint
(a) to the top, and supplied with steam by a pipe connected with
a boiler, and having another pipe or valve for the escape of the con-
densed steam. This chamber should be proportionate to the size of
the gutta percha chamber; for a machine or apparatus which makes a
single fuse and of the size above specified a steam chamber two inches
in the clear will be sufficient. D, is the piston for pressing down the
gutta percha, allowing the powder chamber or funnel B, to pass
through its centre. G, G, is the cistern of cold water supplied by a
pipe, for the purpose of cooling the tube L, and the fuse before the
latter emerges from the orifice F, the surplus water being carried off by
a waste pipe. J, is a thread which is introduced into the centre of the
powder chamber B, for the purpose of creating by its motion a constant
supply of gunpowder to the fuse, and passes through the tube L.
IT, H, is the bench or bed to which the apparatus is fastened; a thread
or yarn being inserted in the central line of the cylinder B, and carried
down quite through the aperture at the bottom, and which thread may

page_text: be wound off a reel or ball placed at any convenient spot. The cylinder
B, is filled with gunpowder and the space A, A, with gutta percha.
The steam being applied until the gum is rendered sufficiently soft,
i. e. is brought to about the consistency of putty, the piston D, D, is
pressed down with a power of about three hundred pounds to the square
inch, by a lever (see Figure 2), or screw, or other convenient means of
applying pressure acting on it, and the thread being gradually drawn
down (as is well understood in the manufacture of safety fuses, and as
is fully described in the Specification of Letters Patent granted to no
and to John Soloman Bickford and Thomas Davey, the Sixth day of
November, in the year of our Lord One thousand eight hundred and
forty-five) the powder becomes surrounded with a coating of gutta
percha, the pressure forcing the gutta percha out at the bottom as the
thread and powder are drawn down, the bore of the tube L, L,
determining the size of the fuse. The requisite pressure being applied
to the gutta percha the fuse may be drawn down through the tube
L, L, by the fingers and rolled up for use, or it may be wound on a
roller, or the fuse may be passed between two rollers revolving against
each other, and in each of which there is a semicircular groove, by
which means the fuse is still further hardened and made firm and
substantial. Secondly, for the coating with gutta percha of a cylinder
or film of gunpowder inclosed in yarns, tape, thread, or other suitable
material, I proceed as follows:-I take an unvarnished fuse, manu-
factured in the same manner as the fuse known as "Bickford's Miners
Safety Fuse,"
or a fuse containing gunpowder within yarns, tape, or
other suitable material, and I cover it with gutta percha of greater or
less thickness, according to the purpose to which it is to be applied.
For this purpose I employ an apparatus shewn in section at Figure 2.
A, is the chamber or vessel containing the gutta percha. This chamber
for the coating of one fuse may be made cylindrical, of about five inches
diameter, as in diagram Number 2, or it may be made of any other
form of about the same capacity, and it may be made larger, according
to the number of fuses which it is intended to coat at the same time.
This chamber should also be formed of a material sufficiently strong to
Dear a pressure of five hundred pounds to the square inch. B, is the

page_text: piston pressed by the lever K, or other mechanical means. C, is the
lower part of the gutta percha chamber beneath the range of the piston,
which descends only to the joint (a, a). D, is a pipe screwed into the
side of the gutta percha chamber and adapted to the size of the fuse to
be coated. It will be necessary to have several of these pipes of the
same external size and form with different sizes of bore, in order
that smaller or larged fuses may be introduced; through this pipe the
fuse passes into the gutta percha chamber to be coated. E, is a pipe
through which the fuse passes after it is coated; several of these
should be provided of different sizes of bore, and adapted to the different
thicknesses of the coating required, as the difference between the bore
of this pipe and the size of the uncoated fuse will regulate the thickness
of the coating. There should be a space or distance of about from one
to two inches between the exit end of the pipe D, and the entrance end
of pipe E. G, G, is the steam chamber, made and arranged as in the
preceding diagram. F, is a water cistern to keep the pipe E, cool and
cool the fuse. H, is the bench to which the apparatus is fastened. L, L,
is the connection between the ram I, and the piston B, by which the
latter is raised when necessary for charging the gutta percha chamber.
Having placed the gutta percha in the cylinder A, and filled the steam
chamber G, G, I introduce a wire with a very small crook in the end
of it at the hole D, passing it through the cylinder and out of the hole
E, fastening a fuse at the end of the wire at D. This being done, as
soon as the gutta percha is sufficiently softened by the action of the
steam. I apply a pressure on the lever of about three hundred pounds
to the square inch, and draw out the wire, and after it the fuse, perfectly
coated with gutta percha, which has been rendered cool and firm by
passing through the cold pipe F; a new length of fuse is then connected
with this by means of a wire similar to that already mentioned, and
thus in constant succession the gutta percha is to be purified and
brought into a state of uniform consistency before being employed for
the purposes above mentioned.
Having now described the nature of my said Invention, and in what
manner the same is to be and may be performed, I declare that I do
not claim the exclusive use of the apparatus herein-before described,

page_text: except when the same is employed in and for the manufacture of my
new safety fuse, and what I claim as the Invention intended to be
secured to me by the berein-before recited Letters Patent is, a safety
fuse coated with gutta percha, as above described.
In witness whereof, I, the said George Smith, have hereunto set 5
my hand and seal, this Eighth day of May, in the year of
our Lord One thousand eight hundred and forty-seven.
Signed, sealed, and delivered by the
within-named George Smith, in the
presence of
H. S. LAW,
GEORGE (L.S.) SMITH.