AN IMPROVED MINERS' LAMP
Year: 1861

page_text: LETTERS PATENT to Isaac Evans, junior, Collier, of Cefn Mawr, Ruabon,
in the County of Denbighshire, North Wales, for the Invention of "AN
IMPROVED MINERS' LAMP."
Sealed the 25th March 1862, and dated the 8th October 1861.
PROVISIONAL SPECIFICATION left by the said Isaac Evans at the
Office of the Commissioners of Patents, with his Petition, on the 8th
October 1861.
I, ISAAC EVANS, junior, Collier, of Cefn Mawr, Ruabon, in the County of
Denbighshire, North Wales, do hereby declare the nature of the said Inven-
tion for "AN IMPROVED MINERS' LAMP," to be as follows:-
In my improved miners' lamp an outer and inner cylinder of glass aro
employed, between which there is an annular space, up which currents of air
are made to pass for the purpose of keeping the glasses cool. On the bottoni
of the lamp containing the oil reservoir, wick holder, and other parts, thero
is a projecting ring perforated laterally to allow air to pass through to a
chamber round the wick holder. This chamber is covered with wire gauze, so
that no air from outside the lamp can reach the flame or pass between the
glass cylinders without first passing through the gauze. The glass cylinders
rest on a ring of metal, which is screwed or otherwise attached to the bottom
part of the lamp. This metal ring is connected by vertical rods to an upper
ring, which holds the upper end of the outer glass cylinder, and other parts of

page_text: the apparatus hereafter mentioned. The lower ring has an annular projection
made thereon provided with vertical holes or perforations. This perforated
annular projection keeps the glass cylinders apart from each other, and in their
proper places at the lower part of the lamp. Atmospheric air is supplied to
the lamp through holes made in the side of the lower ring, and from thence
into an annular space between the lower outer ring and the perforated pro-
jecting ring on the burner part of the lamp. The atmospheric air having passed
into the annular chamber beneath the wire gauze at the lower part of the
lamp passes through the gauze, and part of it goes to the flame to support
combustion, and part passes up through the perforated annular projection
between the two glasses. Above the top of the outer glass cylinder and inside
the upper ring is placed a crown plate provided with a perforated annular pro-
jection, which serves to keep the upper part of the outer cylinder in its place.
These perforations in the crown plate allow the air in the annular space
between the glasses to pass into a space or chamber above, formed by a conical
cap or cover made of wire gauze. I prefer to use two gauze caps or covers,
one of coarser meshes than the other. The heated air and gaseous products
of combustion arising from the flame are conducted into this space or chamber
by a metallic cone placed on the top of the inner glass, and which cone by
resting on the crown plate also serves to keep the inner glass in its place. In
this space the heated air or gases from the flame are commingled with the
air that passes up the annular space between the glasses. The perforated
crown plate, the metal cone, and the wire gauze caps or covers are kept in
their places by means of a metal ring, which is screwed or otherwise
attached to the upper ring of the lamp.
may be protected by a tin or other metal cap provided with openings to
allow the heated gases to escape from the top of the lamp. It is important
that the several parts of the lamp should bo so secured that the miner will be
unable to take them asunder, or obtain access to the light. For this purpose
both the top and bottom parts of the lamp are locked by means of a screw or
screws, which pass through both the moving parts at top and bottom of the
lamp, and prevent them from being detached. These screws are provided with
triangular shaped heads, which are countersunk in sockets, and therefore can
only be turned by means of proper keys,
The wire gauze cap or covers

page_text: SPECIFICATION in pursuance of the conditions of tho Letters Patent, filed
by tho said Isaac Evans in the Great Seal Patent Office on the 8th
April 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ISAAO
EVANS, junior, Collier, of Cefn Mawr, Ruabon, in the County of Denbigh,
North Wales, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of October, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Isaac Evans, Her special license that I, the said Isaac Evans,
my executors, administrators, and assigns, or such others as I, the said
Isaac Evans, 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 "AN IMPROVED
MINERS' LAMP," upon the condition (amongst others) that I, tho said Isaac
Evans, by an instrument in writing under my hand and seal, should par-
ticularly 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 Isaac Evans, do hereby declare
the nature of the said Invention, and in what manner the same is to bo
performed, to be particularly described and ascertained in and by the follow-
ing statement, reference being had to the Drawing hereunto annexed, and to
the letters and figures marked thereon (that is to say) -
The improved miners' lamp, which forms the subject of the present Inven-
tion, is shewn in the accompanying Drawing, in which Fig. 1 is an external
elevation of the lamp; Fig. 2 is a vertical section of the same; Fig. 8 is a
horizontal section, taken in the line a, b, of Fig. 2; Fig. 4 is another hori-
zontal section, taken in the line c, d, of Fig. 2; and Fig. 5 is a similar view,
taken in the line e, f, of Fig. 2. It will be seen that the lamp is provided
with an outer and inner cylinder of glass marked respectively a and b;
between these two glasses there is an annular space c, up which currents of
air are made to pass for the purpose of keeping the glasses a and b cool. On
the bottom of the lamp containing the oil reservoir d, the wick holder 6 and

page_text: other parts there is a projecting ring f, perforated laterally to allow air to pass
through to a chamber g round the wick holder. This chamber is covered with
wire gauze h, so that no air from outside the lamp can reach the flame or pass
between the glass cylinders a and b without first passing through the
gauze h.
The glass cylinders rest on a ring of metal i, which is screwed or otherwise
attached to the part of the lamp. This metal ring i is connected by vertical
rods to an upper ring 'k, which holds the upper ends of the outer glass
cylinders a, and certain other parts of the apparatus hereafter mentioned. The
lower ring f has an annular projection i' made thereon, provided with vertical
holes or perforations, as seen best in Fig. 2. This perforated annular pro-
jection i¹ keeps the glass cylinders a and b apart from each other, and in their
proper places at the lower part of the lamp. Atmospheric air is supplied to
the lamp through holes made in the side of the lower ring i and f, and from
thence through the perforations in the lower outer ring i, and the perforated
projecting ring f on the burner part of the lamp into the annular space g
around the burner. The atmospheric air having passed into the annular
chamberg beneath the wire gauze h, at the lower part of the lamp passes
through the gauze, and part of it goes to the flame to support combustion, and
part passes up through the perforated annular projection i' between the two
glasses a and b, as indicated by the arrows, and up the annular space c, in
doing which the glasses a and b are kept cool. Above the top of the outer
glass cylinder a, and inside the upper ring, is placed a crown plate 1, provided
with annular projecting flanges, which serve to keep the upper part of the
outer and inner glass cylinders a and b in their places. Between these pro-
jecting flanges are made a series of perforations in the crown plate to allow
the air in the annular space c between the glasses a and b to pass into a space
or chamber m above, formed by a conical cap or cover n, made of wire gauze.
I prefer to use two gauze caps or covers, as shewn in the Drawing, the inner
cap or cover being made with coarser meshes than the other. The heated
air and gaseous products of combustion arising from the flame are conducted
into this space or chamber in by a metallic cone o attached to and forming
part of the crown plate b, or merely placed on the top of the inner glass b.
In this space m the heated air or gases from the flame are commingled with
the air that passes up the annular space c between the glasses a and b. The
perforated crown plate 2, with the metal cone o, and the wiro gauze caps or
covers n, n, are kept in their places by means of a metal ring p, which is
screwed or otherwise attached to the upper ring k of the lamp. The wire
gauze caps or covers n may be protected by a tin or other metal cap 9, pro-
vided with openings to allow the heated gases to escape from the top of the

page_text: lamp. It is important that the several parts of the lamp should be so secured
that the miner will be unable to take them asunder, or obtain access to the
light. For this purpose both the top and bottom parts of the lamp are locked
by means of a screw or screws r, r, Figs. 1 and 5, which pass through both
the moving parts at top and bottom of the lamp, and prevents them from
being detached. These screws are provided with triangular-shaped heads,
which are countersunk in sockets, and therefore can only be turned by means
of proper keys.
Having now described my Invention of an improved miners' lamp, and
having explained the manner of carrying the same into effect, I claim as the
Invention secured to me by Letters Patent, as aforesaid, the combination of
parts hercin set forth, or any mere modification thereof, whereby the atmo-
spheric air supplied to the lamp may be divided into two streams, one of
which will pass to the burner to support combustion, and the other stream
up the annular channel between the glasses to a space or chamber above,
where it will mingle with the gaseous products of combustion arising from the
flame.
In witness whereof, I, the said Isaac Evans, have hereunto set my hand
and seal, this Fourth day of April, in the year of our Lord One
thousand eight hundred and sixty-two.
Signed, sealed, and delivered by the above-
named Isaac Evans the younger, in the
presence of
THOMAS V. ROYLE, Solicitor,
Chester.
ISAAC EVANS, JUN. (L.S.)