IMPROVEMENTS IN THE CONSTRUCTION OF GAS LAMPS
Year: 1859

page_text: LETTERS PATENT to David Doig, of the City of Manchester, Engineer,
for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF GAS LAMPS."
A communication from abroad by William Gilbert Ginty, of Rio de
Janeiro, in the Empire of Brazil.
Sealed the 19th August 1859, and dated the 12th April 1859.
Office of the Commissioners of Patents, with his Petition, on the
12th April 1859.
I, DAVID DOIG, of the City of Manchester, Engineer, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF GAS
LAMPS, being a communication from William Gilbert Ginty, of Rio de Janeiro,
in the Empire of Brazil. to be as follows:-
This Invention consists in the use or application of glass prisms or triangular
or nearly triangular pieces of glass, either connected together by being cast in
a mould or otherwise made. or in separate pieces, and introduced or inserted
or placed in or on the top or upper squares or pieces; or instead of such tops
in a square, circular. or any other form of street or other gas lamps of any
and all shapes, and in such form and manner as will refract, reflect, bend, or
otherwise divert horizontally, or at any angle or angles. and different angles
downwards, the rays of light proceeding from the ordinary gas burner or other
burners used, or to be used hereafter, by which all, most, or some of the said rays
[Price 8d.1

page_text: hitherto lost or nearly lost upwards in space, or through the top or top squares
or pieces forming the top of ordinary gas lamps, or lost or nearly lost by the
use of tin or copper lamp tops. are rendered available or partially available for
the purposes of the illumination of the surface of public or other streets or
places. Also, in the substitution of glass or glass and metal framing for and
instead of the ordinary tin or copper, or other opaque framing with which the
panes or pieces of glass which form the sides and tops of ordinary street gas
lamps are connected, by which substitution or means the shadows thrown or
made by the said tin or copper or other opaque framing in ordinary and
general use are avoided, or in great part avoided, and the rays hitherto lost
are preserved, or in great part preserved, for the purposes of practical and
useful illumination..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Doig in the Great Scal Patent Office on the 11th
October 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I. DAVID
DOIG, of the City of Manchester, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of April, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said David Doig, Her special licence that I, the said David Doig.
my executors, administrators, and assigns, or such others as I, the said
David Doig, my 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 "IMPROVEMENTS IN THE
CONSTRUCTION OF GAS LAMPS," a communication from abroad by William
Gilbert Ginty. of Rio de Janeiro, in the Empire of Brazil, upon the con-
dition (amongst others) that I. the said David Doig, my executors or
administrators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertained 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.

page_text: NOW KNOW YE, that I, the said David Doig, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement
(that is to say)-
The nature of this Invention consists first. in the use or application of glass
prisms, or triangular or nearly iriangular pieces of glass placed horizontally or
nearly so, in or on to the upper part of street or other gas lamps.
And secondly, in the substitution of glass, or of glass combined with metal, for
and instead of the ordinary tin or other opaque framing of street gas lamps.
The practical application of these improvements in the construction of gas
lamps will be fully understood by referring to the accompanying Sheet of
Drawings, and to the following explanation.
Figure is an elevation in section of the circular top of a gas lamp drawn
full size, the prisms or triangles for reflecting or refracting the rays of light,
form annular rings on its surface; Figure 2 is an elevation of the same drawn
half size; in these views the lines a, a, represent the angles of incidence of
the rays of light from the burner b, and the lines, c, represent the angles of
reflection or refraction: Figure 3 is an elevation, and Figure 4 a transverse
section, drawn full size, of a plate of glass forming one side of the top of a
square gas lamp. the prisms or triangular projections for reflecting or
refracting the rays of light are placed horizontally as in Figures 1 and 2; the
Drawings convey a general idea of the arrangement adapted to ordinary street
gas lamps, but it is evident that the details can be modified to suit all sizes
and forms of lamps.
From the foregoing description and Drawing it will be seen that the pecu-
liarity of the Invention consists in the use or application of glass prisms, or
triangular or nearly triangular pieces of glass, either connected together by
being cast in a mould, or otherwise made, or in separate pieces, and intro-
duced or placed horizontally or nearly so, in or on the top or upper squares
or pieces, or in substitution of such tops, or squares or pieces, in a square,
circular, or other form, of street or other gas lamps, of any and all shapes,
and in such form and manner, and at such angles as will refract, reflect, bend,
or otherwise divert horizontally, or at any angle or angles, and different angles
downwards, the rays of light proceeding from the ordinary gas burners, or
other burners, by which all, most, or some of the said rays hitherto lost or
nearly lost, or to some extent lost upwards into space, or through the top, or
top squares or pieces forming the top of ordinary gas lamps, or lost or nearly
lost by the use of tin or copper lamp tops are rendered available or partially
available or more available or useful for the purposes of illumination.

page_text: The second part of this Invention may be fully understood without the aid of
Drawings; it consists in the use and substitution of glass or glass and metal
framing for and instead of the ordinary tin, copper, iron, or other opaque or
non-transparent framing with which the frames or pieces of glass which form
the sides) and tops or bottoms of an ordinary street gas lamp or other
lamps are connected. by which substitution or means the shadows thrown from
or made by the said ordinary tin, or copper, or iron, or other opaque framing
in ordinary and general use are avoided. or to a great extent avoided or
diminished in darkness. intensity, or size, and by which substitution the rays
thereby hitherto lost or partially lost, are preserved or partially preserved for
the purposes of practical and useful illumination, the said glass framing, or
glass and metal framing, may be of such form or forms as will conveniently
admit of the sides, top, squares, or panes of glass. being secured thereto in
the ordinary or any other way, and the said glass or glass and metal framing
to be so made either by being cast or blown, or otherwise secured round or
upon copper or other wire. or pieces of metal passing through its entire length
or partially so, and in such manner as will admit of their being secured
together at the ends by nuts and screws, cotters, soldering, or brazing, or in
any other simple manner..
Having thus stated the nature of the Invention as communicated to me by
the said William Gilbert Ginty, and described the manner of performing the
same, I declare that I claim,-
First, the use or application of glass prisms, or triangular or nearly trian-
gular pieces of glass placed horizontally or nearly so. in or on to the upper
part of street or other gas lamps, as shewn and described.
And, secondly, the substitution of glass, or of glass combined with metal,
for and instead of the ordinary tin or other opaque framing of street gas lamps
as described.
In witness whereof. I, the said David Doig. have hereunto set my hand
and seal, this Twelfth day of October. in the year of our Lord One
thousand eight hundred and fifty-nine.
DAVID DOIG. (L.S.)