IMPROVEMENTS IN THE MANUFACTURE OF LAMPS USED FOR ILLUMINATING PURPOSES"
Year: 1883

page_text: LETTERS PATENT to George Wood of Warrington in the County of Lancaster
for an Invention of "IMPROVEMENTS IN THE MANUFACTURE OF LAMPS USED
FOR ILLUMINATING PURPOSES" C
C
PROVISIONAL SPECIFICATION left by the said George Wood at the Office
of the Commissioners of Patents on the 28th November 1883..
GEORGE WOOD of Warrington in the County of Lancaster "IMPROVEMENTS IN
THE MANUFACTURE OF LAMPS USED FOR ILLUMINATING PURPOSES
"
This invention is designed principally to be applied to the manufacture of street
lamps for burning gas but it is also applicable to other kinds of lamps employed
for external or internal illumination whether the light is produced by. the
combustion of gas, oil, spirit, or other fluid or solid matter or by electricity...
The objects of the invention are to increase the illuminating power of the lamps
and at the same time to produce a more pleasing or ornamental effect.
The invention relates to the manufacture of the glass shades or lanterns enclosing
the flame or light of such lamps, and consists principally in manufacturing such
shades or lanterns from pressed glass with a smooth or plain surface outside and
of a prismatic form inside.
For example in manufacturing a street lantern I make the lower half of the
body of the lantern of one piece of glass by pressure in a mould, the exterior of
the same being (by preference) of a smooth truncated conical form, the larger
diameter being uppermost and being provided at its upper edge with a projecting
flange by means of which it is supported in a perforated metal ring forming part
of the frame of the lantern.
The inside of this cone is made in the form of a number of prisms or prismoids
united at their edges and tapering downwards in accordance with the conical form
of the exterior.
This prismatic or prismoidal form of the interior greatly increases the luminous
effect of the light enclosed therein. The upper part of the lantern and the metal
bottom whereby it is attached to the pillar may be made in the usual manner.

page_text: I would here remark that instead of making the outer side of the glass shade or
lantern of a conical form it may be made in the form of an inverted truncated
pyramid having any desired number of sides, and in this case the internal prisms
or prismoids may be either tapered, as in the case of the conical lantern, or they
may be formed with parallel sides, that is, in the shape of a true prism.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Wood in the Patent Office on the 27th May 1884.
"IMPROVEMENTS IN
GEORGE WOOD of Warrington in the County of Lancaster
THE MANUFACTURE OF LAMPS USED FOR ILLUMINATING PURPOSES
"
This invention is designed principally to be applied to the manufacture of street
lamps for burning gas, but it is also applicable to other kinds of lamps employed
for external or internal illumination whether the light is produced by the com-
bustion of gas, oil, spirit, or other fluid or solid matter or by electricity.
The objects of the invention are to increase the illuminating power of the lamps
and at the same time to produce a more pleasing or ornamental effect.
The invention relates to the manufacture of the glass shades or lanterns enclosing
the flame or light of such lamps and consists principally in manufacturing such
shades or lanterns from pressed glass with a smooth or plain surface outside and of
a prismatic form inside.
Such being the nature and object of my said invention I will now proceed to
describe in detail the manner in which the same is to be or may be performed, and
in order that the same may be clearly understood I have annexed hereunto a sheet
of drawings illustrative thereof and have marked the same with figures and letters
of reference corresponding with those in the following explanation thereof.
For the sake of example I have shown my invention in the drawings as applied
to the manufacture of a street lantern as represented in vertical section at Fig. 1..
in the annexed drawings.
For example in manufacturing a street lantern I make the lower half a, a of the
body of the lantern of one piece of glass by pressure in a mould, the exterior of
the same being (by preference) of a smooth truncated conical form, the larger
diameter being uppermost and being provided at its upper edge with a projecting
flange b, b by means of which it is supported in a perforated or other metal ring c, c
forming part of the frame of the lantern. The inside of this cone a, a is made in
the form of a number of prisms or prismoids united at their edges and tapering
downwards in accordance with the conical form of the exterior (see also horizontal
section Fig. 2).
This prismatic or prismoidal form of the interior greatly increases the luminous
effect of the light enclosed therein. The upper part d, d of the lantern and the
metal bottom e, e whereby it is attached to the pillar may be made in the usual
manner.
I would here remark that instead of making the outer side of the glass shade
or lantern of a conical form it may be made in the form of an inverted truncated
pyramid having any desired number of sides, and in this case the internal prisms

page_text: or prismoids may be either tapered as shown in horizontal section Fig. 3 and as in
the case of the conical lantern (Fig. 1) or they may be formed with parallel sides,
that is, in the shape of a true prism, as shown in horizontal section at Fig. 4.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed I wish it to be
understood that I claim as my invention
The manufacture of the lower part of glass shades or lanterns of street and other
lamps from pressed glass (with a smooth or plain surface outside and of a prismatic
or prismoidal form on the inside, substantially in the manner and for the purposes
herein before more particularly set forth.
In witness whereof I the said George Wood have hereunto set my hand and seal
this twenty fourth day of May in the year of our Lord one thousand eight
hundred and eighty four
GEORGE WOOD (La)