IMPROVEMENTS IN APPA- BATUS FOR ILLUMINATING PUBLIC CLOCKS, WHICH IMPROVEMENTS ARE ALSO DURAS "
Year: 1875

page_text: LETTERS PATENT to Joseph Challender, of Manchester, in the
County of Lancaster, for the Invention of "IMPROVEMENTS IN APPA-
BATUS FOR ILLUMINATING PUBLIC CLOCKS, WHICH IMPROVEMENTS ARE ALSO
DURAS "
PROVISIONAL SPECIFICATION left by the said Joseph Challender at
the Office of the Commissioners of Patents, with his Petition, on
the 24th March 1875.
I, JOSEPH CHALLENDER, of Manchester, in the County of Lancaster,
5 do hereby declare the nature of the said Invention for “IMPROVEMENTS
IN APPARATUS FOR ILLUMINATING PUBLIC CLOCKS, WHICH IMPROVEMENTS ARE ALSO
APPLICABLE TO OTHER ILLUMINATING PURPOSES," to be as follows:-
The principal object of this Invention is to illuminate the whole disc
or dial of a church or turret clock with the smallest expenditure possible

page_text: of gas or other artificial light, and without throwing any shadow thereon
from the arbor or spindle which carries the hands.
Immediately behind the dial I place a reflector having the form of a
hollow truncated cone, whereof the truncated and is open and the dial
forms the base. Within the point where the apex of the cone would be
(if it were not truncated) but outside the plane of truncation I place
two gas jets or other lamps (one on each side of the arbor or spindle)
and thus it will be evident that the lights being placed within the apex
of the cone will be equally reflected all over the dial, whilst at the same
time, as they are outside the plane of truncation, the product of com-
bustion from the gas will pass quite clear, and will not tarnish or soil
the reflecting surface.
In some cases I also propose to place a small concave reflector behind
the lights in the centre. Of course if a very large dial is to be illu-
minated a proportionate number of gas or other lights must be
employed.
It will be evident that the above described arrangement is applicable
to illuminate any circular, octagonal, or other similar surface, but if it
be desired to illuminate a rectangular surface (whether square or oblong)
then all that is necessary is to substitute a reflector of a truncated
pyramidal form for the cone, placing the lights, as before, within the
apex, but outside the plane of truncation, and the system is then
applicable to railway signal and other lamps or lanterns, and if an
elongated reflector and three, four, or more gas lights are used it may be
employed for lighting or illuminating shop signs, billiard tables, and
other useful purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Challender in the Great Seal Patent Office
on the 24th September 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSЕРи 3
CHALLENDER, of Manchester, in the County of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of March, in the

page_text: year of our Lord One thousand eight hundred and seventy-five, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Joseph Challender, Her special
license that I, the said Joseph Challender, my executors, administrators,
and assigns, or such others as I, the said Joseph Challender, 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
APPARATUS FOR ILLUMINATING PUBLIC CLOCKS, WHICH IMPROVEMENTS ARE ALSO
APPLICABLE TO OTHER ILLUMINATING PURPOSES," upon the condition (amongst
others) that I, the said Joseph Challender, my executors or admini-
strators, by an instrument in writing under my, or their, or ono of
their 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 I, the said Joseph Challender, 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 and accompanying Drawings:-
The principal object of this Invention is to illuminate the whole disc
or dial of a church or turret clock, with the smallest expenditure possible
of gas or other artificial light, and without throwing any shadow thereon
from the arbor or spindle which carries the hands.
Such being the nature and object of my said Invention, I will now
proceed to describe more in detail the manner in which the same is to
be or may be performed or carried into practical effect, 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.
Fig. in the annexed Drawing is a sectional view, showing the
application of my Invention to a turret clock. a, a, is part of the wall

page_text: is the arbor.
Immediately behind the dial b, b, I place a reflector e, e, having the
form of a hollow truncated conc, whereof the truncated end is open and
the dial b, b, forms the base. Within the point where the apex of the
cone would be (if it were not truncated, see dotted lines) but outsido
the plane of truncation I place two gas jets or other lamps f, f. (one on
each side of the arbor or spindle) or more if required, and thus it will
be evident that the lights being placed within the apex of the cone e, e,
will be equally reflector all over the dial b, b, whilst at the same time as
they are outside the plane of truncation the products of combustion from
the gas will pass quite clear, and will not tarnish or soil the reflecting
surface.
In some cases I also propose to place a small concave or plane
reflector g, g, behind the lights f, f, in the centre. Of course if a very
large dial is to be illuminated a proportionate number of gas or other
lights must be employed.
It will be evident that the above described arrangement is applicable
to illuminate any circular, octagonal, or other similar surface, but if it
be desired to illuminate a rectangular surface (whether square or oblong)
see vertical section, Fig. 2, and front view, Fig. 3, then all that is
necessary is to substitute a reflector or reflectors h, h, of a truncated
pyramidal form for the conc, placing the lights f, f, as before, within
the apex, but outside the plane of truncation, and the system is then
applicable to railway signal and other lamps or lanterns, and if an 1
elongated reflector and three, four, or more gaslights are used it may be
employed for lighting or illuminating shop signs, billiard tables, and
other useful purposes.
Having now described the nature and object of my said Invention,
together with the manner in which the same is to be be or may be or
may be perrformed or carried into practical effect, I wish it to be under-
stood that I claim as my Invention the improved system of illumination
herein-before described and illustrated by the annexed Drawings, and
more especially I claim the combination of the truncated conical or
pyramidal reflector, with the lights placed outside the line of truncation,

page_text: but inside the apex of the cone or pyramid, substantially in the manner
and for the purposes herein-before set forth and described.
In witness whereof, I, the said Joseph Challender, have hereunto
set my hand and seal, this Twenty-first day of September, in
the year of our Lord One thousand eight hundred and seventy-
five.
Witnessed by
GEORGE DAVIES, C.E.,
Patent Agent,
Manchester.
JOSEPH CHALLENDER. (L.S.)