IMPROVEMENTS IN SAFETY MAGAZINE LAMPS
Year: 1873

page_text: LETTERS PATENT to Edmund Thomas Gardner, of the Strand, in the
City of Westminster, Lamp Manufacturer, for the Invention of
"IMPROVEMENTS IN SAFETY MAGAZINE LAMPS."
Sealed the 11th November 1873, and dated the 24th May 1873.
PROVISIONAL SPECIFICATION left by the said Edmund Thomas
Gardner at the Office of the Commissioners of Patents, with his
Petition, on the 24th May 1873.
I, EDMUND THOMAS GARDNER, of the Strand, in the City of
Westminster, Lamp Manufacturer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN SAFETY MAGAZINE LAMPS," to be as
follows:-
The object of my Invention is to construct a lamp that may be used
in powder magazines and other dangerous places with perfect safety.
It is well known that in powder magazines a considerable amount of
powder in the form of fine dust is frequently found floating in the
atmosphere, and this fine dust is liable to ignite and cause an explosion
if it comes in contact with a naked flame. To prevent this danger (in my

page_text: improved lamp) the air passages which supply air to the flame to support
combustion, and also the exit passages for the gaseous production of
combustion are constructed in such a manner that the air or gases must
pass in a zig-zag or serpentine direction, so that when air charged with
explosive dust obtains access to the flame the dust will burn or explode
inside the lamp, but the flame produced thereby cannot return to the
outside.
The oil reservoir which carries the burner is hinged to one side of the
casing at the bottom, and is secured in place by a lock which will keep
everything secure. Air to support combustion enters the lamp under
an inverted outer ledge, and then passes through holes made in the
casing to a narrow space formed by an inner lining, so that the air must
first pass up to reach the holes in the casing, then down the inner space,
and finally up another narrow space between the lining and the oil
reservoir. The top part of the lamp is constructed on substantially the
same principle, that is, the exit air passages are made zig-zag, but as
they are liable to become clogged with soot two out of three parts which
form the passages are hinged to the casing, and are secured in place by
a bolt which can only be released by obtaining access to the interior.
When these parts are unbolted they may be turned back on their
hinges, and easily cleared of any soot that may have become deposited
thereon.
In constructing the outer casing of the lamp care should be taken
that there are no projecting parts where dust can casily settle and
accumulate.
The lamp may be provided with a bull's eye or other lens in front, and
with strong plate glass sides protected from accidental injury by cross
wires or metal bars.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of May, in the year of our.
Lord One thousand eight hundred and seventy-three, in the thirty-sixth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Edmund Thomas Gardner, Her special licence that
I, the said Edmund Thomas Gardner, my executors, administrators, and
assigns, or. such others as I, the said Edmund Thomas Gardner, 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 SAFETY MAGAZINE LAMPS," upon the condition (amongst others) that I,
the said Edmund Thomas Gardner, 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 Edmund Thomas Gardner, 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 the following statement, reference being had to the Drawing
hereunto annexed, and to the letters and figures marked thereon (that is
to say):
The object of my Invention is to construct a lamp that may be used
in powder magazines and other dangerous places with perfect safety.
It is well known that in powder magazines a considerable amount of
powder in the form of fine dust is frequently found floating in the
atmosphere, and this fine dust is liable to ignite and cause an explosion
if it comes in contact with a naked flame. To prevent this danger the
air passages which in my improved lamp supply air to the flame to
support combustion, and also the exit passages for the gaseous products
of combustion are constructed in such a manner that the air or gases
must pass in a zig-zag or serpentine direction, so that when air charged
with explosive dust obtains access to the flame the dust will burn or
in powder magazines and other dangerous places with perfect safety.
It is well known that in powder magazines a considerable amount of
powder in the form of fine dust is frequently found floating in the
atmosphere, and this fine dust is liable to ignite and cause an explosion
if it comes in contact with a naked flame. To prevent this danger the
air passages which in my improved lamp supply air to the flame to
support combustion, and also the exit passages for the gaseous products
of combustion are constructed in such a manner that the air or gases
must pass in a zig-zag or serpentine direction, so that when air charged
with explosive dust obtains access to the flame the dust will burn or

page_text: explode inside the lamp, but the flame produced thereby cannot return
to the outside.
The oil reservoir which carries the burner may be hinged to one side
of the casing at the bottom, and secured in place by a lock which will
keep everything secure, or it may be dropped in from the top, as shewn
in the accompanying Drawing, in which Fig. 1 is a vertical section of
one of my improved lamps, and Fig. 2 is a horizontal section of the
same.
It will be seen that the air to support combustion enters the lamp
under an inverted outer ledge a, a, at bottom, and then passes through
holes made in the casing, as indicated by the arrows, and enters a narrow
space 6 formed by an inner lining c, so that the air must first pass up to
reach the holes in the casing, then down the inner space b, and finally
up another narrow space between the lining and the oil reservoir d.
The top part of the lamp is constructed in substantially the same
manner, that is, the exit air passages are made zig-zag or serpentine, so
that the air to escape from the lamp must pass out in the direction
indicated by the arrows. As the exit air passages may possibly become
clogged with soot, two out of the three parts e, f, g, (which form the
passages) are hinged to the casing, and are secured in place by a bolt
which can only be released by removing a padlock or other equivalent
device which will secure the bolt. The part e is made in the form of a
truncated pyramid open at top, and is simply dropped into its place, in
which it is supported by a projecting flange which rests on the top edge
of the body of the lantern. The part fis of a somewhat similar form,
but is closed at the top, and is hinged at one side to the body of the
lantern as at f¹. The lower part of the part f is perforated all round
with holes to allow the heated air to pass into a space h formed by the
lower part of the cover g, which is provided with a hook or loop g¹
which passes over a staple i, so that it may be secured by a transverse
bar and padlock, as will be easily understood. The lantern is carried by
a bale or handle ; in the ordinary manner. When the parts ƒ and g are
unbolted they may be turned back on their hinges, and easily cleared of
any soot that may have become deposited thereon.
11

page_text: The lamp may be provided with a bull's eye or other lens in front, as
shewn at k, and with strong plate glass sides protected from accidental
injury by cross wires or metal bars as at k*.
The burner and oil reservoir d are of the ordinary construction, and
when the wick is ignited the lamp may be lowered into the lantern by
the wires d', d', fixed at the corners of the oil reservoir. The hinged
parts and g may then be secured in their places as shewn in the
Drawing.
Although the rectangular form shewn in the Drawing is the most
convenient shape for the lantern, it will be obvious that the external
shape of the lantern may be varied without departing from the nature
and object of my Invention.
Having now described my Invention of "Improvements in Safety
Magazine Lamps," and having explained the manner of carrying the
same into effect, I claim as the Invention secured to me by Letters
Patent as aforesaid, constructing and arranging the passages for the
entrance of the air to support combustion, and for the exit of the heated
air and gaseous products of combustion, in the manner and for the
purpose herein set forth.
In witness whereof, I, the said Edmund Thomas Gardner, have
hereunto set my hand and seal, the Twenty-second day of
November, in the year of our Lord One thousand eight hundred
and seventy-three.