IMPROVEMENTS IN MINERS' SAFETY LAMPS
Year: 1867

page_text: LETTERS PATENT to David Pemberton Morison, of Pelton Colliery,
Chester-le-Street, in the County, of, Durham, Mining Engineer, for the
Invention of "IMPROVEMENTS IN MINERS' SAFETY LAMPS."
aled the 31st December 1867, and dated-the-3rd-July 1867:
PROVISIONAL SPECIFICATION left by the said David Pemberton Morison
at the Office of the Commissioners of Patents, with his. Petition,. on the
3rd July 1867.
I, DAVID PEMBERTON MORISON, of Pelton Colliery, Chester-le-Street, in
the County of Durham, Mining Engineer, do hereby declare the nature of
the said Invention for. " IMPROVEMENTS IN MINERS' SAFETY LAMPS," to be as
follows:-
My improvements in miners' safety lamps are applicable to lamps in which
the air necessary to support combustion is admitted through perforations above
the cylinder or cylinders surrounding the flame, and also to lamps wherein such
air is supplied through perforations below the said cylinder or cylinders, and
are designed to prevent in an explosive mixture any communication between
the flame of the lamp (or any ignited gas inside the lamp) and the surround-
ing explosive mixture, even when the explosive gas is pressed against the lamp
at a high velocity.
In lamps where the air enters above the cylinder surrounding the flame I
employ for the top of the lamp a cylinder made of brass or other metal in lieu
of the: metallic wire gauze now -generally in use; into which cylinder I
[Price 6d.]

page_text: place at short intervals from the top discs of perforated copper. By this means
I effectually prevent any communication between the exterior and surrounding
explosive mixture, and the interior of the lamp by the top of the lamp. The
air for sustaining combustion is admitted at the top of two cylinders of glass
or other material surrounding the light through a ring of wire gauze, and is
conveyed downwards between these cylinders to the wick of the lamp after
again passing through one or more rings of wire gauze or perforated copper
placed at the bottom of the said cylinders; over the top of these two cylinders
I place a protecting shield of brass or other metal in order to break the force
of any strong current of explosive mixture. By these means I form a lamp
which has been proved by experiments to be practically safe even in a strong
current of explosive mixture.
In lamps in which the air is admitted through perforations placed in or
about the bottom of the lamp I cause the air to pass under a protecting shield
of brass or other metal through a disc of wire gauze or perforated copper,
then through rings of wire gauze before reaching the flame. I also employ
in this lamp a cylinder of glass which entirely surrounds an interior cylinder
of wire gauze and prevents any current whatever of air or explosive mixture
from reaching the interior of the lamp. A lamp constructed in this manner
has been proved by direct experiment practically safe, not passing the flame
even at very high currents.
Another benefit claimed by this Invention is the obviating by means of the
shield of any obstruction by dust or other matter to the passing of the air
through the perforated holes.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Pemberton Morison in the Great Seal Patent Office
on the 2nd January 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
PEMBERTON MORISON, of Pelton Colliery, Chester-le-Street, in the County
of Durham, Mining Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of July, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said David Pemberton Morison, Her special licence, that I, the said David
Pemberton Morison, my executors, administrators, and assigns, or such others

page_text: .
as 1, the said David Pemberton Morison, 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 MINERS' SAFETY LAMPS," upon the condition (amongst
others) that I, the said David Pemberton Morison, my executors or adminis-
trators, 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 David Pemberton Morison, do hereby
declare the nature of my said Invention, and in what manner the samic is to
be performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the Drawings hereunto
annexed, that is to say:::
My improvements in miners' safety lamps relate, firstly, to lamps in which
the air necessary to support combustion is admitted through perforations above
the cylinder or cylinders surrounding the flame; and, secondly, to lamps in
which such air is supplied through perforations below the said cylinder or
cylinders, and are designed to prevent in an explosive mixture any communi-
cation between the flame of the lamp (or any ignited gas inside the lamp) and
the surrounding explosive mixture even when the explosive mixture presses
against the lamp at a high velocity.
In lamps where the air enters above the cylinder surrounding the flame
I employ for the top of the lamp in lieu of the metallic wire gauze now
generally in use a cylinder of sheet iron, brass, or other suitable non-per-
forated material forming a chimney, or instead of being cylindrical this
chimney may be composed of two converging cones. In this chimney I place
at short intervals from each other and from the top discs (or only one disc
may be employed) of wire gauze or perforated copper. By this means I
effectually prevent any communication between the exterior surrounding
explosive mixture and the interior of the lamp by the top of the lamp. The
air for sustaining combustion is admitted at the top of two cylinders of glass
or other material surrounding the light, through a ring of wire gauze, and is
conveyed downwards between these cylinders to the wick of the lamp after
again passing through one or more rings of wire gauze or perforated copper
placed at or near the bottom of the said cylinders; or the air may be admitted

page_text: at the bottom of the two glass cylinders and pass up between them to enter
the combustion chamber at its upper part. Over the top of these two
cylinders (or at their lower end if the air enters at the bottom) I place a.
protecting shield of brass, iron wire gauze, or other' suitable material 'in order
to break the force of any strong current of explosive mixture. By these
means I form a lamp which has been proved by experiments to be practically
safe even in a strong current of explosive mixture.
Figure 1 of the accompanying Drawings is an elevation and Figure 2 a
vertical section of a lamp constructed in the manner herein-before described.
E; F, are two cylinders of glass.or. other suitable material having an annular
space between them. down which the air necessary for sustaining combustion
passes, as indicated by the arrows; G. is a ring of wire. gauze..at the top.of.the
annular space; and H represents one or more rings also of wire gauze at the
bottom of the said space, through which rings the air passes before entering
the inside of the lamp;. S is a protecting shield to break the force of a strong
current of explosive mixture; D is the chimney forming the top of the lamp
and composed of two converging cones of brass or other metal; B is a disc
of wire gauze inserted in the upper part of the chimney D. Any desired
number of these discs may be employed. C is an outer cylinder of wire gauze
which however may be dispensed with. The other parts of the lamp require
no description.
In lamps in which the air is admitted through perforations placed at or
about the bottom of the lamp I cause the air to pass under a protecting shield
of brass or other metal, through a series of perforations, then through a ring
of wire gauze, and another series of perforations before reaching the flame. I
also employ in this lamp a cylinder of glass which entirely surrounds an
interior cylinder of wire gauze, and prevents any current whatever of air or
explosive mixture reaching the interior of the lamp. A lamp constructed in
this manner has been proved by direct experiment practically safe, not allowing
the flame to pass even at very high currents.
Another benefit obtained is the obviating by means of the shield of any
obstruction by dust or other matter to the passing of the air through the
perforations. Figure 3 is an elevation, and Figure 4 a vertical section of the
lower part of a lamp constructed in the manner last described. C is a shield
to protect the perforations from strong currents of explosive mixture and
from becoming obstructed by dust or other matter. A is an outer series of
perforations; B, a ring of wire gauze, and D an inner series of perforations
through which two series of perforations and ring of gauze the air for sustaining
combustion must pass before reaching the flame; E is a glass cylinder entirely

page_text: surrounding an interior cylinder F of wire gauze; G is a socket into which the
upper part of the glass cylinder E fits; H is a disc of wire gauze at the top
of the lamp. The other parts of this lamp require no further description.
And having now described the nature of my said Invention, and in what
manner, the same is to be performed, I declare that I claim as my "Improve-
ments in Miners Safety Lamps,"
First, constructing such lamps with a chimney D, substantially as herein-
before described and represented in Figures 1 and 2 of the accompanying
Drawings.
Second, the combination with the chimney D of one or more discs of wire
gauze or perforated copper B, substantially as herein-before described and
represented in Figure 2 of the accompanying Drawings.
Third, the combination of parts of lamps, substantially as herein-before
described and represented in Figures 1 and 2 of the accompanying Drawings.
Fourth, constructing lamps with a shield C, substantially as and for the
purposes herein-before described and represented in Figures 3 and 4 of the
accompanying Drawings.
Fifth, the combination of paris of lamps, substantially as herein-before
described and represented in Figures 3 and 4 of the accompanying Drawings.
In witness whereof I, the said David Pemberton Morison, have hereunto
set my hand and seal, this Twenty-seventh day of December, One
thousand eight hundred and sixty-seven.
DAVID PEMBERTON MORISON. (L.S.)