IM- PROVEMENTS IN APPARATUS FOR LIGHTING, APPLICABLE ALSO FOR SIGNALLING PURPOSES
Year: 1870

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of
<< IM-
PROVEMENTS IN APPARATUS FOR LIGHTING, APPLICABLE ALSO FOR SIGNALLING
PURPOSES."- A communication from abroad by Auguste Prosper
Berlioz, of the Firm of Auguste Berlioz and Company, Constructors
of Magneto-Electric Machines, of Paris, in the Empire of France.
COMPLETE SPECIFICATION filed by the said John Henry Johnson at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 17th February 1870, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Mid-
dlesex, Gentleman, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
IN APPARATUS FOR LIGHTING, APPLICABLE ALSO FOR SIGNALLING PURPOSES," and
have petitioned Her Majesty to grant unto me, my executors, adminis-

page_text: made solemn Declaration that the same is communicated to me from
abroad by Auguste Prosper Berlioz, of the Firm of Auguste Berlioz and
Company, Constructors of Magneto-Electric Machines, of Paris, in the
Empire of France.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare that the following Complete Specification, under my hand and
scal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement, reference being had to the accompanying Drawings, and to
the letters and figures marked thereon, that is to say :—
This Invention has reference to a peculiar construction and arrange-
ment of apparatus suitable for use in sca-going ships in foggy weather
or at night time or as a means of lighting up the works of besieged or
besiegers in military operations. This lighting apparatus, to which the
Inventor gives the name of the "Du Buisson lamp," may also be
employed for making various combinations for signalling purposes, and
is mounted on a stand which permits of the light being directed in any
horizontal as well as vertical angle. The light employed is by preference
the electric light, produced by a magneto-electric machine, although the
Invention is not confined to that description of light.
The Drawing annexed represents one form of apparatus adapted for
use on board ship near the fore mast so as to embrace in succession every
point of the horizon.
Figure 1 represents an external clevation of the apparatus completely
mounted; Figure 2 is a vertical section taken through the axis,
and Figure 3 is a horizontal section taken along the line 1-2 in
Figure 2.
The apparatus consists of a cast-iron cylinder C which affords great
facility for placing and fixing the various parts required for its use.
The trunnions of this cylinder are mounted in a brass frame made in two
piecos c which rest upon a metal cap p mounted on a vertical pivot in
the cast-iron stand P fixed to a platform on the deck of the ship, In
order to maintain the vertical inclination given to the cylinder C there
is fitted to one of its trunnions a hand lever M, the axis of which is
screwed as shewn in Figure 3, and which serves to tighten the
cylinder C against its supports c. The cylinder is closed at the back by
a copper plate d in the centre of which there is provided a rectangular

page_text: door d for the introduction or removal of the electric light or other lighting
apparatus A. The front of the cylinder is closed by a glass D fixed in
a frame which is hinged at D', and is kept closed by a hinged fastening b
provided with a milled headed tightening screw. The glass D serves to
protect the annular lenses L, which are arranged in accordance with the
small voltaic arc of the electric light, and have the effect of imparting
the greatest intensity to the light. The several annular lenses are fixed
in a cross support in one piece with the brass ring 1, which is fixed by
screws into an annular recess in the cylinder C. The electric lamp A
is completed by a reflector R mounted on the rod or spindle a, in order
that when the lamp is adjusted so as to give more or less divergence to
the light the reflector may always remain in proper focus. The reflector
is so mounted as to pivot on the axis a in order to bring into the axis
of the carbon points a disc ", which thus serves for the centring of the
said carbon points (see the red lines in Figure 3), these points having
been properly centred the reflector is returned to its place, that is to say,
in the position shewn by black lines in Figures 2 and 3. The lamp is
moved in slides disposed longitudinally in the cylinder C, and it is caused
to advance or recede by means of an adjusting screw V which is worked
from the outside of a cylinder by a milled head v (Figure 1). By thus
advancing or withdrawing the lamp more or less divergence is given to
the light. If preferred any other kind of light may be substituted for
the electric light whilst still preserving the general arrangement of the
apparatus. In the interior of the apparatus there is fitted a small
glass K, carried in one of the trunnions of the cylinder for the purpose
of shewing the image of the carbon points upon a piece of ground glass
at k, upon this glass there is marked a datum point which indicates the
proper focal position of the light. The wires which conduct the electric
currents from the magneto-electric machine pass into the interior of one
of the supports of the cylinder C in order that they may not be subjected
to the action of salt water which might occasionally close the circuit; onc
of the wires which terminates in a spring is shewn at y (Figure 3). The
apparatus is capable of turning in any direction in a horizontal plane since
there are no attachments to the lamp, it is fixed in any given horizontal
direction by means of a tightening handle which is not shewn in the
Drawings.

page_text: Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is, the peculiar
construction, arrangement, and combination of apparatus for lighting
and signalling purposes as herein-before described and illustrated by
the Drawings.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is, the peculiar
construction, arrangement, and combination of apparatus for lighting
and signalling purposes as herein-before described and illustrated by
the Drawings.
In witness whereof, I, the said John Henry Johnson, have to
this my Specification set my hand and seal, the Seventeenth
day of February_One_thousand-eight-hundred-and-seventy.
J. HENRY JOHNSON. (L.S.)