IMPROVEMENTS IN LAMPS
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
ALEXANDER MILLER, of Piccadilly, in the County of Middlesex, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of
Great Britain and Ireland, bearing date at Westminster, the Third day of
July,Onethousand eight hundred and forty-seven, in the eleventh year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said George Alexander Miller, my exors, admors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the George Alex-
ander Miller, my exors, adiñors, and assigns, and such others as I, the said
George Alexander Miller, my exors, admoors, or assigns, should at any time
agree with, and no others, from time to time and at all times during the
term of years therein expressed, should and lawfully might make, use, exer-
cise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, my Invention of "IMPROVEMENTS IN LAMPS;" in which said Letters
Patent is contained a proviso, that I, the said George Alexander Miller,
shall cause a particular description of the nature of my said Invention, and
in what manner the same is to be performed, by an instrument in writing
under my hand and seal, to be inrolled in Her Majesty's High Court of
Chancery within six calendar months next and immediately after the date
of the said in part recited Letters Patent, as in an by the same, reference
being thereunto had, will more fully and at large appear.
::

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
George Alexander Miller, do hereby declare that the nature of my said
Invention, and the manner in which the same is to be performed, are fully
described and ascertained in and by the following statement thereof, reference
being had to the Drawings hereunto annexed, and to the figures and letters
marked thereon, that is to say :-
Secondly, my Invention relates to a mode of manufacturing glass reflectors.
And,
Thirdly, my Invention relates to certain improvements in glass lenses used
in lamps.
And in order that my Invention may be fully understood, and readily carried
into effect, I will proceed to describe the means pursued by me.
The first part of my Invention has for its object a peculiar mode of
arranging or combining parts of reflectors, whereby a strong light may be
produced to a wider extent than heretofore from a lamp, and to an extent of
about one hundred and twenty degrees.
Figure 1 shows the shape of a reflector, which consists, from the part a to b,
of about one half of an ordinary parabolic reflector used to reflect the rays of
light falling thereon in a direction parallel to, or nearly parallel to, the axis d;
and the part from 6 to c consists of another curve, the object of which
is to disperse the rays of light falling thereon, as indicated by the yellow
dotted lines, though the direction in which those rays are deflected may be
varied, and the manner of generating such curve is hereafter explained. The
reflector a, b, c, is shewn to consist of a large number of planes, from which
the rays of light are thrown off at the points aº, aº, b, e, e³, e¹, es, but in
practise the reflector will be so formed as to consist of a curve which will touch
at those points a*,a,b,e,e,e,e,&c.,as is well understood in making reflectors.
In making the part of the reflector from 6 to c I first determine upon the
extent of diffusion of light I wish to obtain from the light supposed to be
situated at the point f, and those rays may be either equally diffused over the
arc determined upon, or any number of them may be concentrated in any
particular locality.
In Figure 1 I have shown the part from 6 to c of the reflector arranged so
as to reflect the rays of light thereon with the greatest intensity at that
part
of the arc which begins with the line d, and gradually to diffuse the rays, so
that the light will be of the least intensity in the direction of g. Upon the
arc d, g, I make a number of points h, h¹, h², h³, ht, h³, h³, &c., at distances

page_text: apart from each other corresponding with the amount of diffusion or concentra-
tion of light I have previously determined upon. I then take a distance b, e,
which distance b, e, when multiplied by the number of points h, h1, h2, h3, h4,
&c., on the arc d', g, will cover about the same number of degrees on an arc
beginning at b, and struck from the point f, as there are degrees in the
arc d',g. I then draw a line from the centre f to the point e, and another
line from the point e to the point h, the one corresponding with a ray of light
falling upon a point at e, the other the ray reflected; and as the angle of
reflection will be the same as the angle of incidence I produce a line from b
passing through at right angles to a line j from e, midway between the
point and the line i (the angle of reflection in this case). The line b, e,
being continued to e¹, equal to b, e, I then take another distance equal to b, e,
and draw another line from the point f to e2, and from 3 to h2 and then
a line midway between the lines i and the point f. From this line j I
obtain a line from the point el at right angles to the line, and produce it to
es, and so on, as shewn by the diagram, Figure 1, I proceed till I have
obtained the points e, e2, e4, &c., desired; I then construct iny reflector of a
curve corresponding with those points, and which will then diffuse the inter-
mediate rays over the intermediate spaces on the arc d¹, g.
78
And I would have it understood that I am aware of reflectors of different
curvatures having been combined before, but, to the best of iny knowledge,
reflectors have never been so combined as partly to reflect the rays of light
falling thereon in lines parallel with the axis d, and partly to diffuse the rays
of light falling thereon at angles across those rays, and this öonstitutes the
peculiarity of this part of my Invention.
It should be stated that the line a, b, c, represents a 'horizontal section of a
reflector, but the vertical section taken through any part of such reflector
would be of a curve such as to reflect the rays of light falling thereon pärralel
with its axis, as is well-understood.
·
I will now describe the second part of my Invention, which consists of
employing in lamps glass reflectors, composed of concave of hollow surfaces
of glass, coated on their convex or outer surfaces with metal, by the well known
process of "quicking;" and in carrying out this part of my Invention I obtain
concave orbent glass of the size and shape desired, and then I have the convex
surface coated with metal by the process of "quicking," which is a process
extensively practised in Birmingham in preparing the surfaces of glass for
making buttons. And I would state that I am aware that Aht glass so treated
has also been cut up into small pieces, and built or fixed into a concave frame,
so as to produce a reflector similar to those which have been made of many
small pieces of looking-glass; but this is objectionable, not only in respect to

page_text: cost, but from the circumstance of the reflector consisting of a very large
number of plain surfaces, in order as nearly as possible to obtain the shape of
reflector desired. And I have found that very excellent reflectors for lamps
may be obtained by first obtaining the glass to the proper concave or bent form
for the reflection desired, and then having it subjected to the well-known
process of "quicking." And I would state that I have found that the plate
glass, manufactured by the Thames Plate Glass Company, bent into the
desired shape and then "quicked," has answered the best for the purpose of
a reflector.
"
I would state, in respect to this part of my Invention, that I do not make
any claim to the making concave or bent glass suitable for a reflector, when
separately considered, nor do I claim the well-known process of quicking glass
when separately considered. But what I claim is, the making of reflectors for
lamps by combining the two, as described.
I will now describe the third part of my Invention, which consists of so
forming the plain surface of a glass lens that the rays of light, passing there-
through in a horizontal direction, shall be diffused at angles to the axis, whilst
.those passing therethrough in a vertical direction will be parralel to the axis,
This part of the Invention also consists of certain additions to a lens, in order
to obtain a better distribution of light; and this part of my Invention also
consists of forming cylindrical or bent lenses for lamps, with the convex portion
towards the interior.
Figure 2 shews a section of a plane convex lens, with corrugations applied,
according to my Invention.
Figure 3 is a view of the corrugated surface of the same. And I would
here remark that, I do not confine myself to either the depth, or the form, or
the number of the corrugations, as the same may be varied, the object being
to cause the rays passing through the lens horizontally to be deflected at
angles to the axis whilst in a vertical direction, those rays will be deflected in
lines parralel with the axis.
Figures 4, 5, and 6, show 3 views of another lens. In this case the object
is attained by simply bollowing the lens in one direction, as shown.
Figure shows the outline of a lamp, with a lens from a to b, such as is
now in use, and by which the rays of light passing therethrough will
go (hori-
zontally) in radial lines from the point d (the locality of the flame). c, c, are
other portious,, which will have the effect of refracting the rays of light
passing through them in lines parallel, or nearly so, with the lens a, b, by which
I am enabled to obtain a more extensive diffusion of light at those parts. And
it is the applying the portions of lenses c, c, to lamps having lenses such as
shown from a to b, which constitutes a novelty under this
part of my Inven-

page_text: tion. The vertical section of the lenses would be focalized to a convexity
suitable to refract the rays passing therethrough vertically into parallel and
horizontal lines, as is well understood.
Figure 8, 9, show a sectional view and plan of cylindrical lens, the peculi-
arity of which consists in the convex side being turned to the interior of the
lamp, by which the lens will be less liable to fracture when coming in contact
with any projecting surfaces in moving the lamp about or otherwise, and its
brilliancy will not be so likely to be impaired by accumulation of snow ordust,
as is often the case when the convex portion of such lens is outwards.
Having thus described the nature of my Invention, and the manner in which
the same is to be performed, I would have it understood that I do not confine
myself to the details herein described, so long as the peculiar character of
either part of my Invention be retained. But what I claim is,-
First, the mode of arranging or of combining the parts of a reflector for a
lamp, as herein explained with respect to Figure 1.
Secondly, I claim the mode of making glass reflectors by employing concave
or bent glass surfaces, with the convex surfaces coated with metal by the
process of "quicking." And,
Thirdly, I claim the mode of constructing glass lenses, as described in
respect to Figures 2, 3, 4, 5, and 6.
I also claim the constructing lamps by applying the portions of lenses c,c,as
herein described.
And also I claim the mode of constructing cylindrical or bent lenses for
lamps, by applying the convex part interior, as herein described.
In witness whereof, I, the said George Alexander Miller, have hereunto
set my hand and seal, this Third day of January, in the year
Lord One thousand eight hundred and forty-eight.
G. A. (L.g.) MILLER.
AND BE IT REMEMBERED, that on the Third day of January, in the
с тя 1010 the aforesaid Coorce Alexander Miller came before