IMPROVEMENTS IN LAMPS
Year: 1858

page_text: LETTERS PATENT to William Crane Wilkins, of Long Acre, in the County
of Middlesex, Lighthouse Engineer, for the Invention of "IMPROVEMENTS
IN LAMPS."
Sealed the 30th November 1858, and dated the 21st June 1858.
PROVISIONAL SPECIFICATION left by the said William Crane Wilkins,
at the Office of the Commissioners of Patents, with his Petition, on the
21st June 1858.
I, WILLIAM CRANE WILKINS, of Long Acre, in the County of Middlesex,
Lighthouse Engineer, do hereby declare the nature of the Invention for
"IMPROVEMENTS IN LAMPS," to be as follows:-
This Invention has for its object improvements in lamps, and consists in an
improved method of arranging safety lamps, such as are used in mines. In
those descriptions of safety lamps, in which the flame of the lamp is surrounded
by glass, considerable difficulty is experienced in bringing a sufficient supply of
air to the flame. To obviate this difficulty I construct a series of tubular
passages through the oil vessel, which communicate at their lower ends with
the external air, and at their upper ends they terminate near the wick, so that
the air which passes into the lamp through these passages comes at once in
contact with the flame; this arrangement is also applicable to other lamps.
In safety lamps, to avoid danger of explosion, the ends of the passages are
covered with wire gauze, or, in place of this arrangement, the oil vessel of the

page_text: lamp may be surrounded by an external case, round the bottom of which a
series of holes are formed for the admission of air; immediately above these
openings the case is provided with a false bottom of wire gauze, and after
passing through this the air passes up all round the oil vessel and enters the
body of the lamp. In order to improve the combustion in the flame and to
prevent the glass from becoming smoked, I employ a small metal tube or
chimney descending from the part of lamp above the glass just to the apex of
the flame; this tube passes through a disc of metal placed immediately above
the glass, so as to divide the upper part of the lamp into two parts; thus the
portion of the lamp surrounded by the glass only communicates with the
portion above, or cylinder of wire gauze, by the metal tube or chimney above
mentioned.
Another part of my Invention consists in a method of constructing signal
lamps for ships. At the present time red and green lights are very generally
used on board ship, to indicate the direction in which the ship which exhibits
the light is steering. In making lamps for this purpose, I fix to them screws
radiating from the centre of the lamp, so as to allow the light to be visible
only over an arc of a little more than 90°, thus preventing mistakes arising
from the light being visible in directions in which it is not required to be seen.
And in order to prevent the red and green lantern from being mistaken the
one for the other at night, I make the handles of the lanterns with guards, so
that one lantern can only be held in the right hand, and the other only in the
left hand.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Crane Wilkins, in the Great Seal Patent Office 2
on the 21st December 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CRANE WILKINS, of Long Acre, in the County of Middlesex, Lighthouse
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 3
Patent, bearing date the Twenty-first day of June, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Crane Wilkins, Her special licence that I, the said
William Crane Wilkins, my executors, administrators, and assigns, or such 3
others as I, the said William Crane Wilkins, my executors, administrators,

page_text: 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 In-
vention for "IMPROVEMENTS IN LAMPS," upon the condition (amongst others)
that I, the said William Crane Wilkins, 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 William Crane Wilkins, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
This Invention has for its object improvements in lamps, and consists in an
improved method of arranging safety lamps, such as are used in mines. In
those descriptions of safety lamps in which the flame of the lamp is surrounded
by glass, considerable difficulty is experienced in bringing a sufficient supply
of air to the flame. To obviate this difficulty I construct a series of tubular
passages through the oil vessel, which communicate at their lower ends with
the external air, and at their upper ends they terminate near the wick, so that
the air which passes into the lamp through these passages comes at once in
contact with the flame, this arrangement is also applicable to other lamps.
In safety lamps, to avoid danger of explosion, the ends of the passages are
covered with wire gauze, or in place of this arrangement the oil vessel of the
lamp may be surrounded by an external case, round the bottom of which a
series of holes are formed for the admission of air; immediately above these
openings the case is provided with a false bottom of wire gauze, and after
passing through this, the air passes up all round the oil vessel and enters the
body of the lamp.
And in order that my said Invention may be most fully understood, and
readily carried into effect, I will proceed to describe the Drawing hereunto
.annexed.
DESCRIPTION OF THE DRAWING.
Figure 1 is a longitudinal section; Figure 2 is a plan; Figure 3 is a side
view; and Figure 4 is a horizontal section of a safety lamp constructed
according to my Invention
a is the oil vassal and h

page_text: through it; they communicate at their lower ends with the space c under the
oil vessel, into which space air from the exterior of the lamp is able to enter
freely by the passages c¹, which are covered with wire gauze, as shown. The
oil vessel is secured to the upper parts of the lamp by a bayonet joint; d is a
ring on the oil vessel in which notches are formed to allow the pins e, fixed on
the ring f, forming part of the upper portion of the lamp, to descend below and
pass under the ring d, and the two portions are secured together by passing the
loop g. over the eye h; and the separation of the parts may be prevented by a
padlock; i is the glass of the lamp, which is, as shown, of a lenticular form in
section, and it is held between the ring f and the upper ring j, which are con-
nected by the bars k, the ring j supports the wire gauze cylinders land m,
two cylinders being employed for greater security; n is a third ring connected
with the ring by the rods o, o, and the loop by which the lamp is carried is
fixed to the ring n, in the manner shown. Figure 5 is an external view, and
Figure 6 is a horizontal section of a safety lamp, differing from that just
described, in that plates of tale are substituted for the glass, the sheets of talc
fit into grooves in the bars k, connecting the rings f and j; Figure 7 is a
vertical section; and Figure 8 is a plan of the lower part of a lamp slightly
modified in construction. a is the oil vessel having air passages 6 formed
around its sides, and which communicate with a space c under the oil vessel,
and open to the air by the openings c¹; and c² is a disc of wire gauze to
prevent flame passing by the passages 6 to the exterior of the lamp.
I would remark that although I have described my Invention as applied to
safety lamps, that it is also applicable to other lamps, the flames of which are
closely surrounded with glass, and where difficulty is found in furnishing a
sufficient supply of air to the flame.
In witness whereof, I, the said William Crane Wilkins, have hereunto
set my hand and seal, this Twentieth day of December, in the year of
our Lord One thousand eight hundred and fifty-eight.
Witness,
E. BARKER.
WILLIAM CRANE WILKINS. (L.S.)