IMPROVE. MENTS IN LIGHTING APPARATUS
Year: 1862

page_text: LETTERS PATENT to Richard Archibald Brooman, of 166, Fleet Street,
in the City of London, Patent Agent, for the Invention of "IMPROVE.
MENTS IN LIGHTING APPARATUS." A communication from abroad by Felix
Lucas, of Nice, France.
Sealed the 20th March 1863, and dated the 23rd September 1862.
PROVISIONAL SPECIFICATION left by the said Richard Archibald
Brooman at the Office of the Commissioners of Patents, with his
Petition, on the 23rd September 1862..
I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City
of London, Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN LIGHTING APPARATUS," (communicated to me from
abroad by Felix Lucas, of Nice, France,) to be as follows:-
This Invention consists of apparatus for reflecting, refracting, or amplifying
light composed of several prismatic or lenticular faces or mirrors made to
rotate round a fixed body of light sufficiently rapidly to cause the flashes of
light to make a continuous impression upon the retina of the observer by
sufficiently frequent periodical shocks, while the eclipses become unperceived
by the observer. The rotary motion of this condenser of light may be con-
tinuous or intermittent, and may be produced by any mechanical force such as
clothwork. The light is stationary, and the luminous rays are in whole or in
part condensed in a narrowed zone; the lenses are prismatic or cylindrical to
produce vertical bands of light. The light may be from oil or gas burners, or

page_text: the electric or other artificial light may be used. There should be at least
three faces or mirrors in the apparatus, but there should not be too many.
about six is the most suitable number. Each of the faces receives a vertical
luminous angle, which it transforms into a luminous band also vertical. The
apparatus does not increase the intensity of the light, but it amplifies the
lighting through a lenticular refraction with entire destruction of dend angles;
It projects the light to a distance.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Archibald Brooman in the Great Seal Patent Office
on the 23rd March 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
ARCHIBALD BROOMAN, of 166, Fleet Street. in the City of London, Patent
Agent, send greeting,
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of September, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of Her
reign, did, for Herself. Her heirs and successors. give and grant unto me, the
said Richard Archibald Brooman. Her special licence that I, the said Richard
Archibald Brooman, my executors, administrators, and assigns, or such
others as I, the said Richard Archibald Brooman, my executors, adminis-
trators, 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 LIGHTING APPARATUS," (com-
municated to me from abroad by Felix Lucas, of Nice, France,) upon the
condition (amongst others) that I, the said Richard Archibald Brooman,
my executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, 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 Richard Archibald Brooman, 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

page_text: following statement thereof, reference being had to the Drawings hereunto
annexed, that is to say:-
This Invention consists of apparatus for reflecting, refracting, or amplifying
light composed of several prismatic, curved, or lenticular faces or mirrors made
to rotate round a fixed body of light sufficiently rapidly to cause the flashes of
light to make a continuous impression upon the retina of the observer by
sufficiently frequent periodical shocks, while the eclipses become unperceived
by the observer. The rotary motion of this condenser of light may be con-
tinuous or intermittent, and may be produced by any mechanical force such as
clockwork. The light is stationary, and the luminous rays are in whole or in
part condensed in a narrowed zone: the lenses are prismatic or cylindrical to
produce vertical bands of light. The light may be from oil or gas burners, or
the electric or other artificial light may be used. There should be at least
three faces or mirrors in the apparatus. but there should not be too many:
about six is the most suitable number. Each of the faces receives a vertical.
luminous angle, which it transforms into a luminous band also vertical. The
apparatus does not increase the intensity of the light, but it amplifies the
lighting through a lenticular refraction with entire destruction of dead angles;
it projects the light to a distance.
The accompanying Drawings illustrate the manner in which this Invention
may be applied to a street lamp. The lenses may he plain prisms, as seen at
a, Figure 1, or they may be gradated, as shewn at '. Figure 2, or cylindrical
as at c, Figure 3.
Figure 4 is a vertical section, and Figure 5 a horizontal section of a gas
burner with a refracting apparatus applied thereto according to this Invention.
a is an ordinary gas pipe, and b the burner. The pipe a carries at c and c¹,
rings or crowns arranged to allow of the rotation therein of a socket d with
If the moving power of the
arms e, each carrying a lenticular prism f.
refracting apparatus be a barrel spring, motion is communicated to the socket d
.by gearing applied on the outside thereof. The body of light is at g; the six
lenticular prisms form a regular hexagon; each lens, which may be plain or
gradated, transforms the angle of incidence A, F, B, into a refracted band.
The lenticular prisms may be divergent or convergent.
The radius of gyration of luminous images may be increased while the
weight of the lenticular apparatus is diminished by employing apparatuses
formed of combinations of lenses or without lenses. Figure 6 is a horizontal
section, shewing an arrangement of divergent apparatus with faces composed
of combinations of lenses. The light coming from the centre g of the
apparatus radiates round that point, and the rays follow the direction

page_text: indicated by the red lines g. i. The movable apparatus h is composed of a
number of faces constituting a regular polygon. In front of each face ha
lenticular apparatus arranged as follows is fixed-A tube receives at that
end which adjoins the face ha converging lens k. the principal focus of which
is at g. In front of this lens k is a second converging lens I, placed in an
inverse direction to the first. and which causes the parallel rays i, 1. which
fall on it to cross each other at the point m. A diverging lens n, placed at the
opposite end of the tube radiales the light and forms a virtual image of the
flame at the point o. This arrangement of lenses is fitted in a case of a
telescope form. The apparatus shewn at Figure 6 has eight arms. The
employment of lenses may be wholly suppressed, but the arrangement in that
case would only be advantageous for certain kinds of light which can be
submitted directly to rotation such as phosphorescent and electric lights. By
means of a simple point or luminous line a circle, a zone, or even a cylinder of
light may be obtained.
And having now described the nature of the said Invention and in what
manner the same is to be performed, I declare that I do not confine myself
to any particular forms, number, or dimensions of the prismatic or cylindrical
faces, mirrors, or lenses, nor to any particular means of imparting rotary
motion to the apparatus, but I claim the apparatus for reflecting,
refracting, or amplifying light, constructed and arranged substantially as
herein-before described and illustrated in the accompanying Drawings.
In witness whereof, I, the said Richard Archibald Brooman, have here-
unto set my hand and seal, this Twenty-third day of March, One
thousand eight hundred and sixty-three.
R. A. BROOMAN. (L.s.)