IMPROVEMENTS IN MINERS' LAMPS
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BENJAMIN
BIRAM, of Wentworth, in the County of York, Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twenty-eighth day of
February, One thousand eight hundred and forty-nine, in the twelfth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Benjamin Biram, my exors, adññors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said Benjamin
Biram, my exors, adñiors, and assigns, or such others as I, the said Benjamin
Biram, my exors, adiñors, or assigns, should at any time agree with, and no
others, from time to time and at all times during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, and in the Islands
of Jersey, Guernsey, Alderney, Sark, and Man, and also in all Her said
Majesty's Colonies and Plantations abroad, my Invention of "IMPROVEMENTS
IN MINERS' LAMPS;" in which said Letters Patent is contained a proviso
that I, the said Benjamin Biram, shall cause a particular description of the
nature of my said Invention, and in what manner the same is to be
performed, by an instrument in writing under my hand and seal, to be
inrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited
Letters Patent, as in and by the same, reference being thereunto had, will
nore fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Benjamin Biram, hereby declare that the nature of the said Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the present Specification thereof, reference being had to
the Drawings hereunto annexed, that is to say :-
My Invention has for its object to encrease the light obtainable from thoso
miners' lamps which are constructed on the principle of what is called "the
Davy lamp," and to afford better protection to the flame from currents of air.
And these several improvements I accomplish by constructing such lamps in
the manner of the one represented in the annexed Drawings.
Figure 1 is an external elevation of this lamp in its complete stato;
Figure 2, a side elevation of it partly in section; and Figure 8, a plan on the
line a', 6'; and Figure 3, a top plan. A is the external case, which is of
the ordinary semicircular form, and suspended by a curved handle F. B is
the oil reservoir and wickholder, a view of which detached from the rest of
the lamp is given separately in Figuro 4. This reservoir is slid into the casing
on grooved or mutually overlapping pieces a, b, one of which is affixed to the
bottom of the case, and the other to the bottom of the reservoir, and c is a ring
by which the reservoir B is pushed into its place, or drawn out when required
to be replenished. C.is the burner with circular tube and wick as usual.
D is a metallic reflector of a parabolic or other suitable curvature, which
is mounted behind the burner on two pins d, d, which rise from the top
of the reservoir B, and take into two short tubes soldered to the back of
the reflector. E is chimney which rises from the top of the case (A),
and may be made either wholly of metal or principally of wire gauze, like the
common Davy lamp. If made of metal it is surmounted by a cap J, which
is closed at top, but perforated in the sides by a circle of holes or slits f, f,
which are protected within by a screw wire gauze 9 (sec Figure 2). e
is a screw by which the cap J is made fast to the chimney, but which can
be undone in order to allow the cap to be removed when it is necessary
to examine, clean, or renew the wire gauze. K (Figure 2) is the door, a
front elevation of which is given separately in Figure 5, this door drops
into grooves made for it in the front edges of the case, and consists of a
metal frame divided into two compartments, the upper and larger of which
m, being that in front of the light is filled with talc, and the lower and
smaller n, is fitted with a portion of wire gauze, through which (alone)
the air necessary to support the flame is supplied. The frame may be made
a little narrower towards the bottom than at top, in order that it may
the more easily be dropped into or raised out of its place; but when it has
been once fixed in its place, care should be taken that it fits accurately

page_text: throughout, and especially that the top flange is brought close down over
the grooves in which the door slides. P is a ring which turns in a seat
made for it on the outside of and close to the bottom of the chimney E. p, a
pin which projects from the ring P, and passing over the top of the door K
secures it in its place. q' is an eye piece which is attached to the back of
the ring P, and is in the diametrical line with the pin p, and q³ a companion
eye piece which is affixed to the top of the caso A, aud against which the
other eye piece abuts when the pin p is moved round into a central
position over the door K. When the two eye pieces are brought side by
side, the hasp of a small padlock W is passed through them and the interior
of the lamp, thus perfectly secured against all meddling or intrusion. Ci
(Figure 2) is a ball and socket or universal joint fixed in the back of the
case A, and R a pricker for raising, depressing, or trimming the wick
which is passed through the ball and through a corresponding opening in
the focus of the reflector D. The pricker is free to inove to and fro' through
the ball, but within certain limits, determined by a twist which is given to it
at the inner end to prevent its being entirely drawn out, and it has thus
the power of universal movement not in one plane only but in as many different
planes as come within the range of its to and fro' movement through the ball.
The lamp when in use may be suspended from a steel spike, such as
represented in Figure 6, driven into the coal or into a wooden prop; and
this spike may have a swivel hook at top, by which it may not only be
attached for convenience of carriage to the haudle F of the lamp, but be
readily turned round from one position into another. When this lamp is
taken into an inflammable atmosphere the noxious gas which passes through
the under or gauze compartment of the door ignites and burns within with
a slight blue flame, and very soon absorbs the supply of oxygen to the lamp,
and extinguishes the flame (unless the lamp is removed into fresh air)
but with no other inconvenience to the bearer than the loss of his light. To
enable a person to work in a part of a mine charged with carburetted hydrogen
(which may sometimes be necessary for a short time) a circular opening
protected by wire gauze may be substituted for the under compartment
n, as indicated by the dotted lines t, t, Figure 1, and a tube of vulcanized
indian rubber or other flexible material fitted to this circular opening, which
tube may be of any length required to reach into the pure air. The lamp
would then burn freely and securely for any length of time,..being supported
with pure air, although the workman himself might, it is true, be exposed to
danger from breathing air deleterious to health, or even destructive of life.
Instead of the door being made in two compartments, one filled with tale and
the other with wire gauze, it may be made with a single opening, by sub-
'

page_text: stituting wire gauze for the talc. Probably for viewers or overmen the tale
may be preferred, and for working miners the wire gauze. I have ascer-
tained by numerous experiments that the light emitted through clear talc is
rather more than that of four candles, and the light emitted through the wire
gauze (in a lamp of my improved description) is about equal to that of an
ordinary pit candle.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that the improvements in
miners' lamps which I claim, as embraced in my said Invention, are,-
First, the combination of a metallic reflector with the burner, as before
described.
Second, the combination with the burner and reflector aforesaid of a front
cover (or loor) composed partly of talc and partly of wire gauze, or wholly of
tale, as before described.
Third, the combination of the parts K, P, p, q, q, and W, in manner
before described, whereby all access to the interior of the lamp is provented,
except by means of a key.
Fourth, the employment of a pricker, to raise, depress, or trim the wick,
revolving on a universal joint, and moving to and fro in the ball of the joiut,
as before described. And,
Fifth, the combination of a wire gauze aperture for the admission of air
to the lamp, with a flexible tube leading from it to the open air, as before
described.
In witness whereof, I, the said Benjamin Biram, have hereunto set
my hand and seal, this Twenty-seventh day of August, in the year of
our Lord One thousand eight hundred and forty-nine.