IMPROVEMENTS IN THE CONSTRUCTION OF SAFETY FUSES FOR MINING AND OTHER PURPOSES
Year: 1878

page_text: LETTERS PATENT to James Polglase, of Southernby, Castle Sowerby, in the
County of Cumberland, Mine Agent, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF SAFETY FUSES FOR MINING AND OTHER PURPOSES."
Sealed the 4th March 1879, and dated the 7th September 1878.
PROVISIONAL SPECIFICATION left by the said James Polglase at the Office
of the Commissioners of Patents on the 7th September 1878.
JAMES POLGLASE, of Southernby, Castle Sowerby, in the County of Cumberland,
Mine Agent.
"IMPROVEMENTS IN THE CONSTRUCTION OF SAFETY FUSES FOR
MINING AND OTHER PURPOSES."
This Invention relates to certain improvements in the construction and mode of
applying a safety fuse for causing the explosion of dynamite, gun cotton, and other
violent and highly explosive compounds used for blasting in mining and other
operations.
The fuse employed for these purposes is similar to that described in the Specifi-
cation of an Invention for "Improvements in Safety Fuses for Mining and other
Purposes," for which Letters Patent were granted to Joseph Victor and myself,
bearing date the 22nd day of March, in the year of our Lord 1861, No. 719, and
which was as follows:-A metallic tube, composed of lead or of any metal or
metallic alloy possessing sufficient ductility and of any desired bore or calibre, was
filled with gunpowder or other explosive substance or compound adapted for such
purposes. The tube thus filled or charged, and having the ends closed by com-
pression, was passed through a series of rollers with graduated grooves, whereby
the diameter and bore of the tube were reduced to any desired minimum, and the
gunpowder or other explosive substance or compound was so tightly compressed as
to give slow or steady combustion instead of sudden explosion.
In accordance with the present Invention the metallic tube, described in the
Specification filed in pursuance of the before-mentioned Letters Patent, the same
by preference being formed of lead, is taken, one end thereof being provided with a
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page_text: screw thread, by means of which it is inserted into the well-known detonator or
cap charged with detonating or fulminating powder, and which is provided with a
screw thread capable of receiving and gearing into the end of the metallic fuse.
Instead of the fuse being connected with the detonator or cap by means of screw
threads it may be inserted into a smooth bore, and made water-tight by any sub-
stance impervious to water, such as white lead, cement, shellac, pitch, tar, resin,
gum, or other substance adapted for the purpose. The fuse and cap being thus
united a wrapper of any suitable material, such as paper, tin or lead foil, cotton,
wool, or silk, rendered adhesive by means of gum or any other suitable adhesive
substance or compound, is wrapped over the joint, the fuse being thereby prevented
from coming into immediate contact with the fulminate, and so constituting a safety.
fuse and detonator.
The cap may be capsuled with india-rubber, gutta percha, tin or lead foil, and
provided with any desired lengths of the safety fuse ready for use.

page_text: SPECIFICATION in pursuance of the conditions of the. Letters Patent filed by
the said James Polglase in the Great Seal Patent Office on the 6th March
1879.
JAMES POLGLASE, of Southernby, Castle Sowerby, in the County of Cumberland,
Mine Agent.
"IMPROVEMENTS IN THE CONSTRUCTION OF SAFETY FUSES FOR MINING
AND OTHER PURPOSES."
1.
My said Invention relates to certain improvements in the construction and mode
of applying a safety fuse for causing the explosion of gunpowder, dynamite, gun
cotton, and other violent and highly explosive compounds used for blasting in
mining and other operations.
The fuse employed for these purposes is similar to that described in the Specifi-
cation of an Invention for "Improvements in Safety Fuses for Mining and other
Purposes," for which Letters Patent were granted to Joseph Victor and myself,
bearing date the 22nd day of March, in the year of our Lord 1861, No. 719, and
which was as follows:-A metallic tube, composed of lead or of any metal or
metallic alloy possessing sufficient ductility and of any desired bore or calibre, was
filled with gunpowder or other explosive substance or compound adapted for such
purposes. The tube thus filled or charged, and having the ends closed by com-
pression, was passed through a series of rollers with graduated grooves, whereby
the diameter and bore of the tube were reduced to any desired minimum, and the
gunpowder or other explosive substance or compound was so tightly compressed as
to give slow or steady combustion, instead of sudden explosion.
In accordance with the present Invention the metallic tube, described in the
Specification filed in pursuance of the before-mentioned Letters Patent, the same,
by preference, being forined of lead, is taken, one end thereof being provided with
a screw thread, by means of which it is inserted into the well-known detonator or
cap charged with detonating or fulminating powder, and which is provided with a
screw thread, capable of receiving and gearing into the end of the metallic fuse.
Instead of the fuse being connected with the detonator or cap by means of screw
threads it may be inserted into a smooth bore, and made water-tight by any sub-
stance impervious to water, such as white lead, cement, shellac, pitch, tar, resin,
gum, or other substance adapted for the purpose. The fuse and cap being thus
united a wrapper of any material, such as paper, cotton, wool, lead or tin foils, or
silk, rendered adhesive by meaus of gum or any other suitable adhesive substance
or compound, is wrapped over the joint, the fuse being thereby prevented from
coming into immediate contact with the fulminate, and so constituting a safety fuse
and detonator.
The cap may be capsuled with india-rubber, and provided with any desired
lengths of the safety fuse ready for use.
Copper, brass, or any other wire or wires may be introduced into the tube when
empty, and the latter then filled with gunpowder or other explosive substance or
compound, the tube being drawn or elongated over the same by means of grooved
rollers. The tube or fuse is thus greatly strengthened and stiffened, and rendered
more applicable for submarine purposes, and may be of great service in using the
electric machine in difficult places by connecting the wires.
Having thus declared and ascertained the nature of my said Invention and the
manner in which it is to be performed, I would observe in conclusion that what I
consider novel and original, and therefore claim as constituting the Invention
secured to me by the said herein-before in part recited Letters Patent is, the con-
struction of safety fuses and the mode of connecting the same with the detonator
or cap containing the detonating or fulminating powder for causing the ignition or

page_text: explosion of the substance or substances used in mining and other operations, sub-
stantially as herein-before described and set forth.
In witness whereof, I, the said James Polglase, have hereunto set my hand
and seal, this Fifth day of March, in the year of our Lord One thousand
eight hundred and seventy-nine.
Penrith, March 5, 1879,
Witness to the above Signature,
A. M'DOUGALL.
JAMES POLGLASE. (L.S.)