IMPROVEMENTS IN SIGNAL LANTERNS
Year: 1856

page_text: LETTERS PATENT to John Weir Draper Brown, of Burrel's Hotel, London
Bridge, and George Gibson Brown, of Deptford Dock Yard, for the
Invention of "IMPROVEMENTS IN SIGNAL LANTERNS."
Sealed the 6th February 1857, and dated the 16th August 1856.
PROVISIONAL SPECIFICATION left by the said John Weir Draper Brown,
and George Gibson Brown at the Office of the Commissioners of Patents,
with their Petition, on the 16th August 1856.
We, JOHN WEIR DRAPER BROWN, of Burrel's Hotel, London Bridge, and
GEORGE GIBSON BROWN, of Deptford Dock Yard, do hereby declare the nature
of the Invention for "IMPROVEMENTS IN SIGNAL LANTERNS," to be as follows:-
This Invention has for its object improvements in signal lanterns. Heretofore,
in signal lanterns, when lenses have been used they have been set in frames, by
which the light has been obscured at the intervals between the lenses.
Now our improvements consist of combining the lenses together at their
edges by grinding and fitting them accurately, thus avoiding the use of any
upright or vertical framing between the several lenses of which a lantern is
composed. The number of lenses used may be varied, but it is preferred to
combine four lenses in each lantern, each lense being a portion of a sphere, so
that externally the lantern will be spherical. The lenses may on their inner
surfaces be plain, convex, or concave. The interior of each lantern is fitted

page_text: with proper means of affording and reflecting light. The lenses of a lantern
may be all white or of different colors, according to the effect desired to be
produced. And when the several lenses, of which a lantern is to be composed,
are each plain on the inner surface, the whole may be cast or formed in one
piece.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Weir Draper Brown and George Gibson Brown in the
Great Seal Patent Office on the 16th February 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
WEIR DRAPER BROWN, of Burrell's Hotel, London Bridge, and GEORGE GIBSON
BROWN, of Deptford Dock Yard, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of August, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Ier reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
John Weir Draper Brown and George Gibson Brown, Her special license
that we, the said John Weir Draper Brown and George Gibson Brown, our
executors, administrators, and assigns, or such others as we, the said John
Weir Draper Brown and George Gibson Brown, our 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 Islo of Man, an
Invention for "IMPROVEMENTS IN SIGNAL LANTERNS," upon the condition
(amongst others) that we, the said John Weir Draper Brown and George
Gibson Brown, our executors or administrators, by an instrument in writing
under our or their hands and seals, or under the hand and seal of one of us or
them, 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 we, the said John Weir Draper Brown and George
Gibson Brown, 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 thereof, that is to say :-

page_text: This Invention has for its object improvements in signal lanterns. Heretofore,
in signal lanterns, when lenses have been used they have been set in frames, by
which the light has been obscured at the intervals between the lenses.
Now our improvements consist of combining the lenses together at their
edges by grinding and fitting them accurately, thus avoiding the use of any
upright or vertical framing between the several lenses of which a lantern is
composed. The number of lenses used may be varied, but it is preferred to
combine four lenses in each lantern, each lense being a portion of a sphere, so
that externally the lantern will be spherical. The lenses may on their inner
surfaces be plain, convex, or concave. The interior of each lantern is fitted
with proper means of affording and reflecting light. The lenses of a lantern
may be all white or of different colors, according to the effect desired to be
produced. And when the several lenses, of which a lantern is to be composed,
are each plain on the inner surface, the whole may be cast or formed in one
piece.
Having thus stated the nature of our said Invention, we will proceed more
fully to describe the manner of performing the same.
DESCRIPTION OF THE DRAWING.
Figure 1 shews a vertical section, and Figure 2 a horizontal section, of a
lantern constructed according to our Invention. In the lantern shown there
are six lenses which butt together at their vertical edges, and consequently the
lantern presents no exterior metal frame between the several lenses. The
lantern shown is for cases where the light is desired to be shewn all round, but
where a less quantity is desired, then the back of the lantern may be of metal
and the front only glazed with lenses, the edges of which butt together. The
form of the top and of the bottom metal frame may be varied. When it is
desired to diffuse the light, then, in place of making the exterior surface of each
lense a portion of a true sphere as shown, we flatten the outer surface of each
lense from the centre in four directions, that is, upwards, and downwards, and
laterally.
In the arrangement shown the top opens on a hinge joint at a, and is
fastened in front by a screw at b, but this may be varied; the top and bottom
parts of the metal frame are connected together by screw bolts c, c, which pass
down through grooves formed in the edges of the lenses; the top and bottom
metal frames might, however, if desired, be fixed to the tops and bottoms of
the lenses without such screw bolts and nuts; and such like connections
between the upper and lower fraines may be used at a distance from the
lenses, either interior or exterior of the lantern. The lenses may be of white

page_text: or of colored glass, and although we prefer, when glazing a lantern all round, to
use six lenses, other numbers may be employed; and when constructing lanterns
only glazed partly around, reflectors may be applied in the ordinary manner.
In witness whereof, we, the said John Weir Draper Brown and George
Gibson Brown, have hereunto set our hands and seals, this Sixteenth
day of February, in the year of our Lord One thousand eight hundred
and fifty-seven.
Vitness,
S. CARPMAEL.
J. WEIR D. BROWN. (L.B.).
GEO. G. BROWN.
(L.B.)