CERTAIN IMPROVEMENTS IN APPARATUS FOR THE PRODUCTION AND DIFFUSION OF LIGHT
Year: 1845

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME. I THOMAS
WRIGHT of Cooper's Hill in the Parish of Thames Ditton in the County
of Surrey Esquire send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria by Her
Letters Patent under the Great Seal of Great Britain bearing date at West-
minster the Tenth day of March in the eighth year of Her reign did för
Herself Her heirs and successors give and grant unto me the said Thomas
Wright my executors administrators and assigns Her especial license full
power sole privilege and authority that I the said, Thomas Wright my exe-
cutors administrators and assigns and such others as I the said Thomas
Wright 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 of years therein expressed should and lawfully might make use exer-
cise and vend within that part of Her said Majesty's United Kingdom of
Great Britain and Ireland called England Her Dominion of Wales and
Town of Berwick-upon-Tweed my Invention of "CERTAIN IMPROVEMENTS
IN APPARATUS FOR THE PRODUCTION AND DIFFUSION OF LIGHT" in which said
Letters Patent there is contained a proviso that I the said Thomas Wright
shall cause a particular description of the nature of my said Invention and
the manner in which the same is to be performed under iny hand and seal
to be enrolled in Her said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part récited
Letters Patent as in and by the same referénce 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
Thomas Wright do hereby declare that the nature of my Invention and the
manner in which the same is to be performed is ascertained and set forth in
and by the following description thereof reference being had to the Drawings
thereunto annexed and to the letters and figures marked thereon that is
to say
A is a double annular frame of wood or other non-conductor of electricity,
between which are placed five (or other number of) discs B1 B2 B3 B4 B5
mounted upon axes revolving in bearings attached to the frame A. These
discs consist of two circular plates of brass or other metal between which are
placed circular discs of plumbago or carbon (the latter being preferred) about
a quarter of an inch in thickness and somewhat larger in diameter than the
containing metal plates having angulär or V-shaped edges. The discs
B B B are mounted in bearings affixed to the frame A but the discs B²
and B* are mounted in sliding carriages capable of being advanced forward or
drawn backward, by means of the adjusting screws C¹ C². These discs are set in
motion by means of a band passing round pulleys on their axes and connected
with wheelwork actuated by a weight or other prime mover, so as to cause
the several discs to revolve with a slow uniform motion. On passing a current
of electricity through the whole series of discs while they are rotating a
brilliant light is produced at the edges of the discs that are adjacent to each
other. This may be accomplished by connecting one wire of a galvanic
battery with the axis of the discs B₁ and the opposite wire with the axis of
the disc B but in order to economize the power I prefer to separate my bat-
tery into four parts and transmit a separate and distinct current to each pair
of discs as shewn in the Drawing. In order to bring about the desired effect
the discs B and B are to be brought in contact with the adjacent discs B¹ B³
and B³ and as soon as the electric current is established and the points of
contact sufficiently ignited the discs B and B are to be withdrawn out of
contact when a brilliant and permanent light will continue to be evolved, at
the several proximate portions of the discs so long as the electric current
passes and the discs continue to revolve. For the equable diffusion of the
electric light thus obtained, I enclose the apparatus berein-before described
within a globe of ground glass as shewn at D or if the whole of the light
is required to be thrown in one particular direction I employ a suitable
arrangement of reflections one of which is shewn at Figure 2 whereby the
whole of the light is thrown in the direction e.f.
Note That I do not confine myself to any particular material or to any
particular mode of obtaining the electric current, nor do I confine myself to

page_text: the precise arrangement of mechanism herein shewn. What I claim as new
and of my Invention is a method of producing a permanent light by con-
tinually presenting one or more fresh points or surfaces of carbon or other
suitable material to the path of an electric current.
Inrolled the same Tenth day of September in the year above written.