IMPROVE- WENMO IN MINERS OR SAFETY LAMPS
Year: 1852

page_text: LETTERS PATENT to Robert Mortimer Glover, of Newcastle-on-
Tyne, Doctor of Medicine, and John Cail, of the same place,
Mathematical Instrument Maker, for the Invention of "IMPROVE-
WENMO IN MINERS OR SAFETY LAMPS."
Sealed the 16th March 1858, and dated the 6th October 1859.
PROVISIONAL-SPECIFICATION left by the said Robert Mortimer
Glover and John Cail at. the Office of the Commissioners of
Patents, with their Petition, on the 6th October 1852.
WC, ROBERT MORTIMER GLOVER and JOHN CAIL, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN MINERS OR
SAFETY LAMPS" to be as follows:-
The principal features of novelty in our improved lamp are, 1st, the
employment of an inner as well as an outer cylinder of glass to surround
the light, and between which two cylinders the air to support combus-
tion is drawn down from above through a perforated plate or wire
gauze, and by its passage between the two glasses keeps the outer one
much cooler than when only one is used; there is, consequently, less
danger of the glass cracking or flying from any cool substance, such as
cold water or a stream of cold air coming suddenly in contact with the

page_text: heated glass. By the employment of two glasses the danger of explo-
sions in the mine is lessened, even if the outer cylinder should by
accident become broken.
Another point of some importance is, the adaptation of a piece of
tube to the lower part of the wire-work chimney, whereby currents
of air are prevented from affecting the steadiness of the light, or
from passing through the wire gauze to the flame. The holes whereby
the air is admitted to the lamp between the glass cylinders are pro-
tected from dust and other inconveniences by a projecting shade. The
height of the wick is regulated in a somewhat different manner to that
usually adopted in ordinary safety lamps, and there are other minor
points which, when combined, form an effective whole, which has been
found by experience to give-very-useful results.--
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Mortimer Glover and John Cail in the
Great Seal Patent Office, on the 6th April 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME; we,
ROBERT MORTIMER GLOVER, of. Newcastle-on-Tyne, Doctor of Medicine,
and JOHN CAIL, of the same place, Mathematical Instrument Maker,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by. Her
Letters Patent, bearing date the Sixth day of October, in the year
of our Lord One thousand eight hundred and fifty-two, in the six-
teenth year of Her reign, did, for Herself, Her heirs and successors, -
give and grant unto us, the said Robert Mortimer Glover and John
Cail, Her special license that we, the said Robert Mortimer Glover
and John Cail, our executors, administrators, and assigns, or such
others as we, the said Robert Mortimer Glover and John Cail, our
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

page_text: "IMPROVEMENTS IN MINERS OR SAFETY LAMPS," upon the condition
(amongst others) that we, the said Robert Mortimer Glover and John'
Cail, by an instrument in writing under our hands and seals, or under
the hand and seal of one of us, should particularly describe and ascer-
fain 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 we, the said Robert Mortimer Glover
and John Cail, do hereby declare the nature of our 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 Drawings hercunto annexed, and to the letters and figures
marked thereon (that is to say):
Our Invention of improvements in miners or safety lamps -relates to
a novel or improved mode of constructing lamps of this description,
so as to obviate the objections to which those hitherto employed in
mines are liable.
In constructing safety lamps to be used in mines or other places'
where there is danger of the flame coming in contact with an inflam-
mable atmosphere it is found necessary to protect or cover up the flame
in such a manner that it can never communicate with the external.
atmosphere, although care is taken to provide a sufficient supply of air
to the burner to support combustion. In-the Davy lamp-this is effected'
by the employment of wire gauze of sufficient-fineness to prevent the
flame from passing through, but yet will allow air to pass through to
the flame: This is the kind of lamp most generally used, but it is by
no means an infallible safety lamp, and is open to the serious ob-
jection that it obscures the light. To remedy these defects the flame
has been surrounded with a glass cylinder, but as this is liable to be
broken by accident, the danger that would inevitably result from such
an accident is so great that any advantages that it might be considered
to possess would be far more than counter-balanced by the serious risk!
The principal features of novelty in our improved lamp are, first, the
employment of an inner as well as an outer-cylinder of glass to sur

page_text: round the light, and between which two cylinders the air to support
combustion is drawn down from above through a perforated plate or
wire gauze, and by its passage between the two glasses will keep the
outer one much cooler than when only one is used; there is, consequently,
less danger of the glass cracking or flying from any cool substance, such
as cold water or a stream of cold air coming suddenly in contact with
the heated glass. By the employment of two glasses the danger of
explosions in the mine is lessened, even if the outer cylinder should by
accident become broken, as there would still remain a strong glass
cylinder between the flame and the external inflammable air, no explo-
sion could therefore take place, and time would thus be allowed to get
the lamp repaired.
Another point of some importance is, the adaptation of a piece of
tube to the lower part of the wire-work chimney, whereby currents of
air are prevented from affecting the steadiness of the light. The holes
whereby the air is admitted to the lamp between the glass cylinders
may, if thought desirable, be protected from dust and other incon-
The
veniences by means of an overhanging or projecting shade.
height of the wick is regulated in a somewhat different manner to that
usually adopted in ordinary safety lamps, and there are other minor
points which, when combined, form an effective whole, which has been
found by experience to give very useful results.
In order, however, that our Invention may be clearly understood
we have shewn in the accompanying Drawings various views of our
improved safety lamp, shewing the peculiar construction and arrange-
ment of the parts.
Fig. 1, is an external elevation of the lamp drawn full size. Fig. 2,
is a vertical section of the same. Fig. 3, is a sectional plan view taken
in the line A... B, of Figs 1, and 2; and Fig. 4, is another sectional
plan view taken in the line C... D, of the same Figures; a, a, is the
lamp or reservoir for holding the oil to supply the wick which is inserted
in the conical tubo b; the wick may be raised, lowered, or otherwise
operated upon by the bent wire c, which passes through the bottom of
the lanp as shewn in Fig. 2. The oil reservoir is screwed into the
bottoni ring d, d, of the lamp, and is secured therein by a screw c

page_text: somewhat in the usual manner; f, f, is the upper ring of the lamp, and
is connected to the lower ring d, by the vertical pins or standards g, g.
An ordinary wire gauze chimney i, i, with a moveable cover j, is secured
in the upper ring f, in any convenient manner, and the lamp may be
carried by a handle, chain, or cord passed through the ring k, above. The
air to support cumbustion in the lamp is made to pass through holes or
openings made in the upper ring f, of the lamp, as seen best in Fig 2,
and 3, and after passing through the meshes of a ring of wire gauze i,
(Fig. 2,) it descends through the annular passage formed between the
two glass cylinders m, and n, which are supported from below, and rest
upon a second ring of wire gauze which lies upon the projecting pieces
0, 0, 0, (Fig. 4,) of the lower ring d, of the lamp. The passage of the
air from outside the lamp to the flame in the interior is indicated
by the arrows. By this arrangement of parts it will be seen that as
the air to support the combustion of the flame must pass down the
annular channel between the two glass cylinders, that cylinder which
is exposed to the external air must be kept cooler than when only one
is employed; the danger of the cylinder becoming broken by any cold
substance coming against it when in a heated state is therefore avoided.
In order to prevent any currents of air from acting on the flame, and
rendering it unsteady, we have placed inside the wire gauze chamber,
and immediately above the flame, a conical metallic tube p, p, which
will not only protect the flame, but also tend to create a steady draft;
and cause the flame to burn brightly. We sometimes protect the
from the action of currents of air by means of a short pipe flame
placed outside and round the lower part of the wire gauze chimney;
we, however, prefer to construct and adapt the tube as shewn in the
Drawings.
Having now described our Invention, and the best means with which
we are at present acquainted for carrying the same into effect, we would
observe, in conclusion, that although we have thought it desirable for
the more perfect explanation of our improvements to shew and describe
various parts of miners lamps which have been heretofore applied to
similar purposes, yet we do not intend to claim any such parts separately
as new or as of our Invention, except when constructed, combined, and

page_text: arranged in the manner above shewn and described, nor do we intend
to confine ourselves exclusively to the precise. arrangement or construc-
tion of parts herein shewn and described, as they may doubtless be
varied without departing from the nature and object of our Invention;
but that which we consider to be new, and therefore wish to claim as
the Invention secured to us by Letters Patent, is, the general arrange-
ment of the parts herein shewn, or any modification thereof, in which
the air to support combustion is made to pass down two cylinders of
glass which surround the flame. We claim the combination of these
glass cylinders with the wire gauze rings as shewn, and also the use or
application of the conical or other metallic tube p, p, or its equivalent,
for protecting the flame from the action of currents of air as above
described.
In witness whereof, we, the said Robert Mortimer Glover and John
Cail, have hereunto set our hands and seals, this Twenty-ninth
day of March, in the year of our Lord One thousand eight
hundred and fifty-three.
Witness,
ISABELLA GLOVER.
R. M. GLOVER. (L.S.)
JOHN CAIL.
(L.S.)