IMPROVEMENTS IN THE ILLUMINATION OF LIGHTHOUSES
Year: 1882

page_text: LETTERS PATENT to John Richardson Wigham, of Albany House, Monkstown
in the County of Dublin for an Invention of "IMPROVEMENTS IN THE
ILLUMINATION OF LIGHTHOUSES
"
PROVISIONAL SPECIFICATION left by the said John Richardson Wigham
at the Office of the Commissioners of Patents on the 28th December 1882.
JOHN RICHARDSON WIGHAM, of Albany House, Monkstown in the County of
Dublin "IMPROVEMENTS IN THE ILLUMINATION OF LIGHTHOUSES"
In the Specification to Letters Patent granted to me on the 5th April 1872
N° 1015, I described an arrangement of superposed lighthouse lenses with a lamp
or burner placed in the common focus of each tier of lenses. My present invention
relates to means of increasing the usefulness of large lights for lighthouse purposes
by placing lenses or lenticular apparatus side by side and providing an illuminant
whether of gas, oil, electric or other light in the focus of each lens so as to form a
much broader beam than has heretofore been used for lighthouse purposes. The
lenses and lights may be arranged so as to form a figure emitting the broad beam
from each of its sides. Or they may be arranged so as to emit two or more such
beams side by side, and if required with minor beams from smaller lenses between
them, or the spaces between the lenses which form the broad beams may be
provided with dioptric or other reflectors throwing back light and heat into the
foci, that is on to the burners. By means of such reflectors I not only utilize the
reflected light but also the heat by raising to a high temperature the burners and
the gas and air which supply them, thereby increasing their illuminating power.
For revolving lights I mount the lenses and burners in a frame that rotates on a
tubular axis having a joint made good by packing but preferably by a seal of
mercury. The central space through which it is not required to transmit light
may be used to accommodate the necessary air flues, gas or oil pipes and other
fittings.
When the illuminants are arranged side by side as above described, one only
need be used in clear weather but in thick weather a second or third may be
employed. Also in each case illuminants may be superposed as described in the
Specification above referred to, so that there may be several tiers in height, each
tier consisting of lenses placed side by side with a lamp or burner in the focus of
each lens.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Richardson Wigham in the Great Seal Patent Office on the
26th June 1883.
JOHN RICHARDSON WIGHAM of Albany House, Monkstown in the county of
Dublin "IMPROVEMENTS IN THE ILLUMINATION OF LIGHTHOUSES
رو
In the Specification to Letters Patent granted to me on the 5th April 1872
N° 1015, I described an arrangement of superposed lighthouse lenses with a lamp
or burner placed in the common focus of each tier of lenses. My present invention
relates to means of increasing the usefulness of large lights for lighthouse purposes
by placing lenses or lenticular apparatus side by side and providing an illuminant,
whether of gas, oil, electric or other light, in the focus of each lens, so as to form a
much broader beam than has heretofore been used for lighthouse purposes. The
lenses and lights may be arranged so as to form a figure emitting the broad beam
from each of its sides, or they may be arranged so as to emit two or more such
beams side by side, and if required with minor beams from smaller lenses between
them, or the spaces between the lenses which form the broad beams may be provided
with dioptric or other reflectors throwing back light and heat into the foci, that is
on the burners. By means of such reflectors, I not only utilize the reflected
light but also the heat, by raising to a high temperature the burners and the gas
and air which supply them, thereby increasing their illuminating power.
For revolving lights, I mount the lenses and burners in a frame that rotates on a
tubular axis having a joint made good by packing but preferably by a seal of
mercury. The central space through which it is not required to transmit light
may be used to accomodate the necessary air flues, gas or oil pipes' and other
fittings.
When the illuminants are arranged side by side, as above described, only one
need be used in clear weather, but in thick weather a second or third may be
employed. Also in each case illuminants may be superposed as described in
the specification above referred to, so that there may be several tiers in height,
each tier consisting of lenses placed side by side with a lamp or burner in the focus
of each lens.
Figs. 1, 2 and 3 of the accompanying drawings, shew by way of example, respec-
tively a front view a side view and a plan of an arrangement of superposed lenses
with lamps or burners, wherein two lenses AA are placed side by side on each
tier and two corresponding lamps or burners, B B are situated respectively in the
focus of each lense according to my above described invention.
The spaces C C between the lenses as also the sides D D, may, as before stated,
either constitute other lenticular apparatus for transmitting light from the burners,
or they may be occupied by dioptric or other reflectors throwing back light and
heat to the focal burners. If the apparatus is arranged to revolve the revolving
supply pipe E for the illuminant is connected to the fixed supply by a suitable
joint at F, by preference provided with a seal of mercury.
Having thus described the nature of my invention and in what manner the same
is to be performed, I claim-
First Arranging two or more lenses or lenticular apparatus side by side in light-
houses, with lamps or burners situated in the focus of each such lense or lenticular
apparatus, substantially as herein described.
Second: In the arrangement of lenses and burners referred to in the preceding

page_text: claim, providing in the spaces between the lenses or lenticular apparatus, dioptric
or other reflecting apparatus for throwing back the light and heat on to the focal
burners substantially as and for the purposes herein described.
In Witness whereof I the said John Richardson Wigham have hereunto set
my hand and seal this twenty third day of June in the year of our Lord,
one thousand eight hundred and eighty-three