IMPROVEMENTS IN LAMPS, AND IN THE CONSTRUCTION OF LENSES AND REFLECTORS
Year: 1870

page_text: LETTERS PATENT to James Couper, the younger, and William Haden
Richardson, both of Glasgow, in the County of Lanark, North
Britain, Flint Glass Manufacturers, for the Invention of "IMPROVE-
Sealed the 24th January 1871, and dated the 20th September 1870.
PROVISIONAL SPECIFICATION left by the said James Couper and
William Haden Richardson at the Office of the Commissioners of
Patents, with their Petition, on the 20th September 1870.
We, JAMES COUPER, the younger, and WILLIAM HADEN RICHARDSON,
both of Glasgow, in the County of Lanark, North Britain, Flint Glass
Manufacturers, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN LAMPS, AND IN THE CONSTRUCTION OF LENSES AND REFLECTORS,"
to be as follows, that is to say:—
The object of this Invention is to improve the illuminating power of
lamps, and more especially of those classes which are used out of doors,
in railway trains, and stations, as well as in vehicles for travelling on

page_text: tramways or common roads, lamps for lighting streets, as well as
household, police, and other hand lamps.
Certain parts of the Invention are also applicable to miners' safety
lamps, and the increased illuminating efficiency is produced by means
of the lenses and reflectors constructed in the manner and of the several
forms herein-after set forth.
When applied to the lamps herein-before referred to other than
miners' safety lamps the improved lenses may be inserted in the lamp
case or lanthorn in the same or similar manner to that in which the
ordinary lenses at present used are inserted, but when applied to miners'
safety lamps the lenses under one arrangement are made annular, so
as to completely encircle the light, and under which arrangement the
lower part of the lamp case or lanthorn is preferably formed with holes
or tubes covered with gauze wire so as to admit the air for combustion
beneath the lens.
And under another arrangement of miners' lamps the lenses in place
of being annular may be constructed of the other forms herein-after set
forth. The said lenses may be used as reflectors, and in which case one
of their surfaces may be silvered or not, or a reflecting surface of metal,
porcelain, or other material may be placed behind them.
In constructing the said lenses and reflectors, the glass of which they
are formed is pressed or blown whilst in the fluid state into moulds of
the required shape, wherein when solidified it permanently receives the
necessary form.
The said lenses and reflectors constructed under this Invention are of
several forms, but in each of which the illuminating power is intensified
through the refraction and reflection of the rays of light by means of
dioptric annuli and prismoidal projections or indentations.
For use in lamps, such as those herein-before referred to, other than
those miners' safety lamps wherein annular lenses are employed, the said
lenses and reflectors may be arranged in various orders as follows, that
is to say-The exterior surface, or what in an ordinary lens would be
the convex surface, may be formed with a series of dioptric rings, ovals,
or other curved figures or segments of such figures, and the inner
surfaces of the said lenses or reflectors may be flat or smooth, concave
or convex surfaces, or such inner surfaces, either when flat, concave, or
convex, may be formed with radial or parallel prismoidal indentations or
projections of triangular, curved, or other section.

page_text: Under another arrangement the dioptric rings, ovals, or other curved
figures or segments thereof are formed on the interior surface of the
lens only, and the prismoidal indentations on the exterior surface, or both
the interior and exterior surfaces may be formed of a series of dioptric
rings, ovals, or other curved figures or segments thereof..
Under another arrangement the dioptric rings, ovals, or other curved
figures or segments thereof may be dispensed with, and either the
interior or exterior surface, or both of them, may be formed with radial
or parallel prismoidal indentations, corrugations, or projections.
Another form of lens or reflector constructed in moulds in the manner
herein-before described consists, primarily, of either an ordinary convex
lens or of a flat surface; and, secondarily, it consists of a series of
smaller convex lenses situated on the primary convex or flat surface.
The said primary convex or flat surface may or may not be surrounded
with dioptric rings, and the surfaces of the smaller or secondary leuses
may be dioptric or prismoidal, and the inner surface of the lens may
be either flat, concave, or convex, and with or without prismoidal
indentations or projections.
An important use of the several lenses hercin-before referred to is for
admitting light through street pavements into cellars or apartments
under ground.
A very efficient lamp for lighting streets or other places may be con-
structed by putting together in a framework several of the lenses herein-
before referred to, so as to either surround a light or burner, or the said
series of lenses may be used as a reflector and placed inside the case of
an ordinary lamp.
In the case of annular lenses for miners' safety lamps or others
wherein such lenses are or may be employed, their exterior surfaces
may be formed with dioptric rings, and the interior surfaces may be
plain or with corrugated, radial, or prismoidal indentations or pro-
jections; or in place of constructing the said annular lenses with
dioptric rings, such rings may be dispensed with, and cither their
inner or outer surfaces, or both of them, formed into prisms, indentations,
or corrugations.
Besides being constructed of crystal or other glass the lenses may
be made of coloured glass, or by the colour being introduced in the
ordinary manner by either spreading it between or inside the glass, or
by "casing "it on either or both of the exterior or interior surfaces.

page_text: The said lenses or reflectors besides being constructed of the curved
form herein-before set forth may be made in figures having straight
lines, and in place of each lens being formed separately two or more
may be pressed or blown in moulds in one picce.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Couper and William Haden Richardson in
the Great Seal Patent Office on the 18th March 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
COUPER, the younger, and WILLIAM HADEN RICHARDSON, both of
Glasgow, in the County of Lanark, North Britain, Flint Glass Manu-
facturers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of September, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said James Couper, the younger, and William
Haden Richardson, Her special license that we, the said James Couper,
the younger, and William Haden Richardson, our executors, adminis-
trators, and assigns, or such others as we, the said James Couper, the
younger, and William Haden Richardson, our executors, administrators,
or assigns, should at any time agree with, and no others, from time
to time and at all times thercafter 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 LAMPS, AND IN THE
CONSTRUCTION OF LENSES AND REFLECTORS," upon the condition (amongst
others) that we, the said James Couper, the younger, and William
Haden Richardson, by an instrument in writing under our hands and
scals, 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 we the said James Couper, the younger,
and William Haden Richardson, do hereby declare the nature of our
said Invention, and in what manner the same is to be performed, to

page_text: be particularly described and ascertained in and by the following state-
ment, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say: -
The object of this Invention is to improve the illuminating power of
lamps, and more especially of those classes which are used out of doors
in railway trains and stations, as well as in vehicles for travelling on
tramways or common roads, lamps for lighting streets, as well as
household, police, and other hand lamps.
Certain parts of the Invention are also applicable to miners' safety
lamps, and the increased illuminating efficiency is produced by means of
the lenses and reflectors constructed in the manner and of the several
forms hercin-after set forth.
When applied to the lamps herein-before referred to other than
miners' safety lamps the improved lenses may be inserted in the lamp
case or lanthorn in the same or similar manner to that in which the
ordinary lenses at present used are inserted, but when applied to miners'
safety lamps the lenses under one arrangement are made annular so as
to completely encircle the light, and under which arrangement the
lower part of the lamp case or lanthorn is preferably formed with holes
or tubes covered with gauze wire so as to admit the air for combustion
beneath the lens.
And under another arrangement of miners' lamps the lenses in place_
of being annular may be constructed of the other forms herein-after set
forth. The said lenses may be used as reflectors, and in which case
one of their surfaces may be silvered or not, or a reflecting surface of
metal, porcelain, or other material may be placed behind them.
In constructing the said lenses and reflectors the glass of which they
are formed is pressed or blown whilst in the fluid state into moulds
of the required shape, wherein when solidified it permanently receives
the necessary form.
The said lenses and reflectors constructed under this Invention are.
of several forms, but in each of which the illuminating power is
intensified through the refraction and reflection of the rays of light by
means of dioptric, annuli, and prismoidal projections or indentations.
For use in lamps, such as those herein-before referred to, other than
those miners' safety lamps wherein annular lenses are employed, the
said lenses and reflectors may be arranged in various orders as follows,
+

page_text: that is to say, the exterior surface or what in an ordinary lens would
be the convex surface, may be formed with a series of dioptric rings,
ovals, or other curved figures or segments of such figures, and the inner
surfaces of the said lenses or reflectors may be flat or smooth; concave
or convex surfaces, or such inner surfaces either when flat, concave, or
convex may be formed with radial or parallel prismoidal indentations
or projections of triangular, curved, or other section.
Under another arrangement the dioptric rings, ovals, or other curved
figures or segments thereof are formed on the interior surface of the
lens only, and the prismoidal indentations on the exterior surface, or
both the interior and exterior surfaces may be formed of a series of
dioptric rings, ovals, or other curved figures or segments thereof.
Under another arrangement the dioptric rings, ovals, or other curved
figures or segments thereof may be dispensed with, and either the
interior or exterior surface, or both of them may be formed with radial
or parallel prismoidal indentations, corrugations, or projections.
Another form of lens or reflector constructed in moulds in the
manner herein-before described, consists, primarily, of cither an ordinary
convex lens or of a flat surface, and secondarily, it consists of a scries
of smaller convex lenses situated on the primary convex or flat surface.
The said primary convex or flat surface may or may not be surrounded
with dioptric rings, and the surfaces of the smaller or secondary lenses
may be dioptric or prismoidal, and the inner surface of the lens may
be either flat, concave, or convex, and with or without prismoidal
indentations or projections.
An important use of the several lenses hercin-before referred to is
for admitting light through street pavements into cellars or apartments
underground.
A very efficient lamp for lighting streets or other places may be
constructed by putting together in a framework several of the lenses
herein-before referred to, so as to either surround a light or burner, or
the said series of lenses may be used as a reflector and placed inside the
case or lanthorn of an ordinary lamp.
In the case of annular lenses for miners' safety lamps or others,
wherein such lenses are or may be employed, their exterior surfaces may
be formed with dioptric rings and the interior surfaces may be plain
ór with corrugated, radial, or prismoidal indentations or projections;
or in place of constructing the said annular lenses with dioptric rings

page_text: such rings may be dispensed with, and either their inner or outer
surfaces or both of them formed into prisms, indentations, or
corrugations.
Besides being constructed of crystal or other glass the lenses may bc
made of coloured glass, or by the colour being introduced in the ordinary
manner by either spreading it between or inside the glass or by
I casing" it on cither or both of the exterior or interior surfaces.
66
The said lenses or reflectors besides being constructed of the curved
form herein-before set forth, may be made in figures having straight
lines, and in place of cach lens being formed separately, two or more
may be pressed or blown in moulds in one piece.
And in order that our said Invention may be properly understood we
shall now proceed more particularly to illustrate the same by reference
to the several Figures upon the two explanatory Sheets of Drawings
which we have hereunto appended, that is to say :-
-
Figure 1, Sheet 1, is a transverse section of a lens or reflector having
dioptric rings a on the interior surface, and with the inner or lower
surface flat; Figure 2, Sheet 1, is a plan of the same. The dotted lines
connecting the section Figure 1 with the plan Figure 2 indicate the
correspondence of parts in one Figure with parts in the other Figure,
and it is to be understood that in the arrangement of lens or reflector
shown at Figures 1 and 2, Sheet 1, as well as in all the examples of
lenses or reflectors herein-after referred to, wherein dioptric prisms are
used in place of using dioptric annuli, ovals or other curved figures
may be employed for the dioptric prisms as may be best adapted for the
nature of or situation and shape of the lamp.
Figure 3, Sheet 1, is a transverse section showing another form of this
class of lens or reflector, the outer surface A of which is similar to that
already set forth and shown at Figures 1 and 2, Sheet 1, whilst its inner
surface C is concave, as shown.
Figure 4, Shect 1, is a section showing another form of lens or
reflector, the feature which distinguishes it from either example already
specified being the form of its inner surface C which is convex, as shown,
its outer surface A being in like manner convex and with annular dioptric
rings corresponding to those shown under the two foregoing examples :-
Figure 5, Sheet 1, is a section, and Figure 6, Sheet 1, is a plan
whereby are illustrated three distinct forms of lens or reflectors, in each

page_text: of which the outer surface A is formed with dioptric annuli, whilst in
one instance the inner surface B is composed of a series of annular and
concentric prismoidal indentations a, recessed into the flat surface, as
more particularly shown at the half plan marked D, Figure 6, Sheet 1,
whilst in a second instance the prismoidal indentations a are arranged
parallel with each other along the inner surface of the lens or reflector
as more particularly shown at the quarter plan marked E, Figure 6,
Sheet 1; and in the third instance the prismoidal indentations a are
arranged radiating from the centre, as more particularly shown at the
quarter plan, marked F, Figure 6, Sheet 1.
Figure 7, Sheet 1, is a transverse section showing a lens or reflector
having on its inner surface a series of prismoidal projections which
may be arranged in any of the three separate methods specified with
reference to the indentations a, set forth under the last examples and
more particularly shown at Figure 6.
Figure 8 is a transverse section of a lens or reflector having dioptric
rings formed upon its outer surface A. as shown, and with its inner
surface B concave, and having prismoidal indentations and projections
formed thereon, and which may be arranged either in concentric rings
as shown at the side marked B, or running parallel to each other
as shown at the side marked A, or in place of the prismoidal indenta-
tions or projections being either parallel or annular, they may be radial.
Figure 9 is a transverse section of a lens or reflector, having its outer
surface A convex, and its inner surface B with prismoidal rings formed
thereon as shown, and Figure 9ª is a transverse section of a similar lens
or reflector, but having the prismoidal rings of a different form.
Figure 10 is a transverse section of a lens or reflector having dioptric
rings formed upon its outer surface A, as shown, and with its inner
surface in like manner convex with prismodial indentations or projec-
tions formed upon it, which may either be arranged in rings concentric
to each other, or in lines parallel to each other, or radiating from
the centre.
Figure 11 is a transverse section of a lens or reflector having pris-
moidal indentations or projections formed upon its outer surface A, and
with its inner surface B having dioptric rings on one plane as shown;
Figure 12, being a plan of the same, and illustrating three distinct modes
of arranging the prismoidal indentations or projections upon the outer
surface. That portion of the plan Figure 12, marked A, shows the said
+

page_text: indentations or projections arranged in rings concentric with each other,
that portion marked B shewing them arranged in straight lines parallel
to each other, whilst that portion marked C shows them arranged
radiating from the centre.
Figure 13 is a transverse section of a lens or reflector having pris-
moidal indentations and projections formed upon its outer surface A in a
manner similar to that set forth with reference to the last preceding
example, and with its inner surface B composed of dioptric rings arranged
in several planes as shewn.
Figure 14 is a transverse section of a lens having prismoidal indenta-
tions or projections formed upon its outer surface A, and having its inner
surface composed of dioptric rings arranged on several planes as shewn.
Figure 15 is a transverse section of a lens or reflector having
prismoidal indentations or projections formed upon its outer surface A,
and with its inner surface flat as shewn.
Figure 16 is a transverse section of a lens or reflector having its outer
and its inner surfaces formed with prismoidal indentations or projections
and the said indentations or projections on one or both sides of the lens
may be either annular, radial, or in straight lines parallel to each other.
Figure 17, Sheet 1, is a side elevation of a lens or reflector having
radiating prismoidal indentations or projections formed upon its outer
surface A, and with its inner surface B concave as shewn.
Figure 18, is an elevation of a lens or reflector having radiating
prismoidal projections formed upon its outer surface A, also with
radiating prismoidal indentations upon its inner surface B as shewn.
Figure 19 is a transverse section of a lens having dioptric rings formed
upon its outer surface A, and with its inner surface B flat as shown.
Figure 20 being a plan of the same. This form of lens is especially
applicable for fitting into a lamp or lanthorn frame, such for example
as that used for street lamps or others of a like nature, each separate
lens being inserted into a different side of the lamp case or lanthorn, and
the said lamp case or lanthorn may be of any desired form or number
of sides; this last form of lens is also adapted for pavement lights, in
which case the side having the dioptric rings or ovals thereon is turned
downwards.
Under other of our improvements in lamps, and the construction of

page_text: lenses or reflectors for the same, annular lenses of the forms herein-after
set forth are included, the said annular lenses being specially applicable
to miners' safety lamps.
Figure 21 is a half clevation and half vertical section of an annular
lens having dioptric rings formed upon its outer surface at both ends
as shewn, and with its inner surface cylindrical. Figure 22 being a
plan of the same.
Figure 23 is a vertical section of an annular lens having dioptric
rings formed upon its outer or convex surface at both ends and with
prismoidal indentations and projections formed upon its inner surface as
shewn. Figure 24 being a plan of the same.
At Figure 25 that side marked A is a half elevation shewing an
annular lens with prismoidal indentations or projections formed upon
its outer surface and with its inner surface smooth, as more particularly
shewn at the side marked A, Figure 26, which is a half plan of the same.
At Figure 25 that side marked B is a half vertical section shewing an
annular lens having its outer surface smooth and with prismoidal inden-
tations or projections formed upon its inner surface as more particularly
shewn at the side marked B, Figure 26, which is a half plan of the same.
At Figure 27 the side marked C is a half vertical section of an annular
lens having semicircular or approximately semicircular projections
formed upon its inner surface and running longitudinally thereon, as
more particularly shown at the side marke C, Figure 28, which is a half
plan of the same. At Figure 27 the side marked D is a half vertical section
of an annular lens having semicircular or approximately semicircular
hollows formed on its inner surface, and running longitudinally thereon
as more particularly shown at the side marked D, Figure 28, which is a
half plan of the same. At Figure 29 the side marked E is a half plan
of an annular lens having segmental projections or indentations formed
on its outer surface and parallel to its axis as shown whilst the side
marked F is a half plan of an annular lens having segmental hollows or
flutes formed upon its outer surface and parallel to its axis. At Figure 30
that side marked G is a half longitudinal section of an annular lens
having prismoidal indentations or projections formed upon its outer
surface and passing round it as shown, whilst the side marked H is a
half longitudinal section of an annular lens with prismoidal indentations
and projections formed upon its inner surface and passing around it as
shown. At Figure 31 that side marked I is a half longitudinal section

page_text: of an annular lens having segmental projections formed upon its outer
surface and passing round it as shown, that side marked I, Figure 32,
is a half plan of the same, and that side of Figure 31, marked K, is a
half longitudinal section of an annular lens having segmental hollows
formed upon its outer surface and passing round it as shown also at
Figure 32 which is a half plan of the same.
Under other of our improvements in lamps and the construction of
lenses and reflectors these consist in the moulding of lenses suitable for
street lamps, roof lights, and other similar purposes with the various
forms of dioptric rings, prismoidal indentations, or corrugations herein-
before specified with reference to the foregoing modifications formed
thereon.
Figure 1, Sheet 2, is a half elevation and half transverse section of a
lens having four different sets of dioptric rings formed upon the outer
surface of the spheroidal part of the lens, whilst upon the upper
cylindrical portion of the lens there are other dioptric rings formed and
passing round it as shown. Figure 2, Sheet 2, is a half elevation and half
transverse section of a lens specially constructed for a lamp of a railway
or other carriage roof, the upper cylindrical part of which has dioptric
rings formed upon its outer surface as shown, whilst the outer surface
of its lower part is convex having dioptric rings formed upon it.
Under another modification our Invention consists in the construction
of lenses to be used for the purpose of admitting light through street
pavements into cellars or other apartments or for other similar purposes.
Figure 3, Sheet 2, is a plan, and Figure 4, Sheet 2, is a transverse section
shewing several arrangements of lenses by which light is admitted
through street pavements, the lenses A may be of any of the several
forms shewn, and are each inserted into spaces formed for their reception
in an iron framework B. Figure 5, Sheet 2, is a plan, and Figure 6 is a
transverse section also shewing an arrangement for admitting light
through pavements differing from the previous arrangement in the
shape or outline of the lenses as is more particularly seen by comparison
of the plans Figures 3 and 5 respectively.
Another arrangement consists of moulding upon a flat surface of glass
a scries of smaller convex lenses as shewn in section at Figure 7,
Sheet 2, and in plan at Figure 9, Sheet 2, or it may be formed in the
manner shewn in section at Figure 8, Sheet 2, that is to say, with small

page_text: convex lenses formed upon one side of the large lens whilst upon its
reverse side cavities are formed opposite each of the small lenses.
Another form of lens for admitting light through pavements is shewn
in plan at Figure 10, Sheet 2, and in section at Figure 11, Sheet 2, that
part marked A is constructed with segmental projections upon the upper
side of the lens as shewn, whilst that part marked B is constructed with
segmental depressions or indentations or flutes upon the side of the lens
as shewn.
Having now described the nature of our said Invention, and the manner
under which the same is or may be carried into effect, we would observe
in conclusion that what we consider novel and original, and therefore
claim as the Invention secured to us by the herein-before in part recited
Letters Patent is,―
First. The construction of lamps for use in railway trains and stations,
in vehicles for tramways or common roads, for lighting streets, and for
household and policemen's use, the cases or lanthorns of which are fitted
with any of the several lenses herein-before described and shown at
Figures 1 to 20, Sheet 1 of the appended Drawings, or any mere
modification thereof.
Second. The application to miners and household lamps of the several
lenses herein described, and shown at Figures 21 to 32, Sheet 1, of the
appended Drawings, or any mere modification thereof.
Third. The construction of the several forms of lenses or reflectors as
and for the purposes herein described and shown on the two annexed
Sheets of Drawings by pressing or blowing the glass in suitable moulds.
In witness whereof, we, the said James Couper, the younger, and
William Haden Richardson, have hereunto set our hands and
scals, this Seventeenth day of March One thousand eight hundred
and seventy-one.