IMPROVEMENTS IN LAMPS FOR RAILWAY CARRIAGES AND OTHER PURPOSES, AND IN THE METHOD OF ÅRBAnging Glass PriSMS IN CON- NECTION THEREWITH
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by Benjamin Pryor Stockman and
John Bennett at the Office of the Commissioners of Patents, with
their Petition, on the 29th September 1878.
We, BENJAMIN PRYOR STOCKMAN and JoHN BENNETT, both of Poets'
Corner, in the City of Westminster; do hereby declare the nature of,
the said Invention for "IMPROVEMENTS IN LAMPS FOR RAILWAY CARRIAGES
AND OTHER PURPOSES, AND IN THE METHOD OF ÅRBAnging Glass PriSMS IN CON-
NECTION THEREWITH," to be as follows :—
•
Our Invention has for its objects an improved method of constructing
and arranging the lamps for burning mineral or other oil, such as are
ordinarily used for lighting railway carriages, but which may also be:
used for other purposes. Also an improved method of arranging glass
prisms in such lamps or in other lamps, so that the light is reflected.
from them, and a greater degree of illumination is thereby obtained than
in lamps as ordinarily constructed.
•
In order to carry out our Invention we take a lamp of any suitable
material but preferably of glass; similar in its action to those ordinarily
used, in which paraffin or other mineral or other oil is burnt, and having::

page_text: either a flat, double, divided or cylindrical wick. This lamp is contained
when in use in a glass bell, pan, or globe, somewhat similar in
appearance to those ordinarily in use for containing the lamps in railway
carriages, and having an opening at the top but also having an opening
at the bottom through which the lamp can be inserted from below. The i
bottom opening has fitted and fixed to it a metal ring, through which
suitable perforations are made for the purpose of admitting air for
combustion.
The glass globe, pan, or bell, described is suspended from the roof of
the railway carriage in a way similar to those ordinarily in use.
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We make the lamp of such a shape that it can be readily inserted into
the globo from below, and it is provided with a metallic band, ring, or
belt, which corresponds with and fits the metal ring at the bottom of the
glass globe already described, and has a suitable slot or hole formed in it
to receive a spring bolt or catch, which is attached to the ring upon the 1
globe, so that when the lamp is pushed up to its proper position it is
retained there and locked or fixed by giving it a slight turn until the
spring bolt.or catch slips into the corresponding hole or slot, the lamp
when in its place being thus sheltered by the outer glass globe. We also
sometimes provide a keyhole in the ring at the bottom of the globe into 2
which a key can be inserted for the purpose of locking or unlocking the
bolt which fixes the lamp and the globe together. "This key-may be
retained by the person in charge of the lamps, and without it the lamp
cannot be removed from the globo or interfered with.
Instead of the glass chimney as ordinarily used for producing a a
draught of air in lamps, we use a chimney consisting of a short cylin
drical, conical, or bulbous glass tube of only sufficient length to cover
the whole of the flame which is required for illumination, and for the
purpose of producing sufficient draught for brilliant combustion we add
an upper tube of any suitable metal (preferably copper) of such a size and a
form as to surround and clasp tightly the upper end of the short glass
tube. The upper part of this metallic tube may be made either cylin-
drical, tapering, or bulbous in shape, and of such a length as to produce.
the most perfect combustion.
The operation of lighting and fixing a lamp constructed according to
our Invention is as follows:-The lamp having been trimmed is lighted,
and the wick having been temporarily turned down sufficiently low the
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page_text: short glass tube is placed in a seating of the perforated or "gallery"
form ordinarily used for supporting the glass chimneys of lamps, and the
metal tube is then put on and pressed down upon the top of the glass
tube, clipping it sufficiently tightly, and so formed as to allow of its
expanding with it under the heat of the flame. The wick may then be
turned up to any required height, and the lamp thus completely adjusted
is pushed up through the bottom of the outer glass globe, and is there
fixed and locked in the manner already described.
Sometimes instead of inserting the lamp into the globe from below, we
insert it from above, in which case the lower locking ring as described
upon the globe will not be required, neither need the opening at the
bottom of the globe be so large as in the arrangement already described,
but only of sufficient size to receive and hold steady the bottom of the
lamp which is suitably formed and adjusted to fit it.
Or sometimes where we insert the lamp into the globe from above, wo
make no opening in the bottom of the globe with the exception of one
or more holes or perforations of sufficient size to admit air for com-
bustion, and in such case the lamp may simply rest upon and be
supported by the bottom of the globe itself.
The glass outer globes may be made of plain transparent glass, or
ground glass, and may be moulded or cut to any pattern or figure and
perforated, and the short glass tubes forming the lower part of the
chimney may be made cylindrical, conical, corrugated, or of any other
suitable shape.
In order to reflect the light in lamps constructed according to our
Invention or in other lamps, so that a greater degree of illumination
may be obtained, we use solid glass prisms (preferably square in cross
section, but which may be made triangular or of other suitable shape in
cross section) as reflectors so cut and placed as to reflect the light from
the flame of the lamp.
For lamps used for lighting railway carriages we arrange these prisms
in a radial position, and fit them upon a suitable metal skeleton framing
which may be of the shape of an ordinary conical lamp shade or of other
suitable shape, and is constructed so that the prisms may fit radially in
suitable recesses, and that any number of such prisms may be used from
two only up to the full number which the skeleton frame will hold,

page_text: The use of such prisms in our Invention is based upon the optical
principle of reflection only, and not that of the refraction and decom-
position of light as used in the prisms ordinarily applied to glass lustres..
We also use glass prisms as described for increasing or multiplying the
illuminating power of lamps, chandeliers, candles, gas, or other burners, {
or any other kind of light, and we arrange them in other forms and
positions as well as in the method already described for railway carriage'
lamps.
For example, we arrange them in perpendicular or horizontal positions,
not in the manner ordinarily used for the prisms of lustres, but elevated
or-placed at such a level as to reflect the light.
•
!
Where the prismatic reflectors are applied to lamps constructed
according to our Invention, we prefer to make the outer margin of such
reflector rest for its support upon a ledge, shelf, or rebate in the outer
glass globe of such lamps, or in the covering ring next the roof of the 1
carriage or other place where such globe is fixed. ..
"Lamps constructed according to our Invention may be used with or
without the reflectors described, and may be used for the purpose of
lighting ships, tramway cars, buildings, and other places, as well as
railway carriages.
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