AN IMPROVEMENT IN THE COLOURED LENSES OF SIGNAL AND OTHER LAMPS OR LANTERNS
Year: 1873

page_text: LETTERS PATENT to John James Nickoll, of South Hill House,
Gravesend, in the County of Kent, Gentleman, for the Invention of
"AN IMPROVEMENT IN THE COLOURED LENSES OF SIGNAL AND OTHER LAMPS
OR LANTERNS."
Sealed the 12th June 1874, and dated the 13th December 1873.
PROVISIONAL SPECIFICATION left by the said John James Nickoll
at the Office of the Commissioners of Patents, with his Petition,
on the 13th December 1873.
I, JOHN JAMES NICKOLL, of South Hill House, Gravesend, in the
County of Kent, Gentleman, do hereby declare the nature of the said
Invention for "AN IMPROVEMENT IN THE COLOURED LENSES OF SIGNAL AND
OTHER LAMPS OR LANTERNS," to be as follows:-
My Invention consists in constructing the coloured lenses of signal
and other lamps by forming the bodies of such lenses of white glass,
and covering one or both surfaces thereof with a thin film or films of
coloured glass, instead of making them of coloured glass throughout as
heretofore practised.

page_text: In some cases instead of covering the outer surface or surfaces with
the film of coloured glass, the lens may be formed of two or more pieces
of white glass having a plate or plates of coloured glass interposed
between them, or having one or more of the surfaces which come
together covered with a film or films of coloured glass.
And in some cases where the coloured media is so interposed between
two surfaces, other transparent colouring media such as coloured
gelatine or balsam may be used instead of glass.
Light passed through coloured lenses constructed according to my
Invention will suffer less diminution of intensity than when passed
through coloured lenses constructed in the ordinary manner.
'
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John James Nickoll in the Great Seal Patent
Office on the 13th June 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN JAMES
NICKOLL, of South Hill House, Gravesend, in the County of Kent,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of December, in the
year of our Lord One thousand eight hundred and seventy-three, in
the thirty-fifth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said John James Nickoll, Her
special licence that I, the said John James Nickoll, my executors,
administrators, and assigns, or such others as I, the said John James
Nickoll, 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,
exercise, use, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"AN IMPROVEMENT IN THE COLOURED LENSES OF SIGNAL AND OTHER LAMPS
OR LANTERNS," upon the condition (amongst others) that I, the said
John James Nickoll, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said
:

page_text: 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 John James Nickoll, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
My Invention consists in constructing the coloured lenses of signal
and other lamps by forming the bodies of such lenses of white glass,
and covering one or both surfaces thereof with a thin film or films of
coloured glass, instead of making them of coloured glass thoughout as
heretofo re pract i.
In some cases instead of covering the outer surface or surfaces with
the film of coloured glass the lens may be formed of two or more pieces
of white glass having a plate or plates of coloured glass interposed
between them, or having one or both of the surfaces which come
together covered with a film or films of coloured glass.
In carrying my said Invention into effect when employing thin films
of coloured glass, I prefer to apply such films to one or both surfaces of
the white glass body of the lens during the process of its manufacture,
and whilst the whole is in the heated state, in the manner well known
to and usually practised by glass makers or workers for coating glass
objects with coloured glass for the purpose of ornamentation or other-
wise, which process being well known to persons skilled in the
manufacture of glass I have considered it unnecessary to describe
herein.
Instead of uniting the white lens together with the coloured film into
one piece, as above described, the film of coloured glass may be moulded
separately and attached to the white lens by means of balsam, or applied
to and held in contact with such lens by the besil of the lamp or by any
other suitable means.
It will be obvious that when the film is moulded separately from the
lens it will be desirable to make it of greater thickness than when
formed in one piece with it, and I therefore prefer to use lenses coated
in the manner first above described.

page_text: Instead of coating the external surface or surfaces of the white glass
lens with a film of coloured glass, I sometimes make the lens of
alternate layers of white glass and coloured films united in the manu-
facture of the lens whilst it is in a sufficiently heated state, so that the
said layers adhere together and form a homogeneous or solid lens of
white glass with one or more coloured films or plates running
through it.
Light passed through coloured lenses constructed according to my
Invention suffers less diminution of intensity than when passed through
coloured lenses constructed in the ordinary manner.
Having now described the nature of my said Invention and the
manner in which the same is to or may be performed, I would have it
understood, that what I claim as my Invention is,―
First. The construction of coloured lenses by coating white glass
lenses with a film or films of coloured glass, as described.
Second. The construction of coloured lenses by applying or attaching
to white glass lenses films or plates of coloured glass moulded separately
therefrom, as described.
Third. Combining layers of white and coloured glass so as to form
solid lenses with a coloured plate or plates running through them, as
described.
In witness whereof, I, the said John James Nickoll, have here-
unto set my hand and seal, this Tenth day of June, in the
year of our Lord One thousand eight hundred and seventy-
four.