Improvements in Illuminating Lighthouses, Beacons, Harbours, Lightships, and Places where Strong and Variable Lights are required.
Year: 1891

page_text: Date of Application, 14th Mar., 1891
Complete Specification Left, 14th Dec., 1891-Accepted, 30th Jan., 1892
PROVISIONAL SPECIFICATION.
Improvements in Illuminating Lighthouses, Beacons, Harbours,
Lightships, and Places where Strong and Variable Lights are
required.
I, JOHN RICHARDSON WIGHAM, of 35 Capel Street, Dublin, Lighthouse
Engineer, do hereby declare the nature of this invention to be as follows:-
In Letters Patent granted to me on the 5th April 1872, No. 1015 I describe a
method of increasing the illuminating power of lighting apparatus as may be
required by the density of the atmosphere, that is, in foggy or thick weather, using
for this purpose lamps or burners for the combustion of gas, oil or other kindred
illuminating agent. My present invention consists in the employment of electricity
for this purpose.
Heretofore electricity has been used as a lighthouse illuminant only in the form
of arc lights to which a twofold objection has been taken 1st. that the arc light is
deficient in red and orange rays, which best penetrate fog, and 2nd. that the arc
light in itself, though exceedingly intense, is very small and thus deficient in the
volume necessary for making an adequate illuminating impression upon fog. My
present invention obviates these two objections, and consists in the use of incan-
descent electric lights, peculiarly constructed to suit lighthouses and other places
requiring similar illumination, which provide the necessary red and orange rays
and the amount of volume useful for fog penetration and illumination. The electric
current may be produced from any form of dynamo or battery, driven by any
motive power, and with or without batteries or accumulators. The incandescent
lamps which I employ, whether in the focus of one lens or tier of lenses or dioptric
refracting apparatus or in biform, triform, quadriform or other multiform applicable
for lighthouse or other illumination, consist of two or more thick wires or carbons
or loops of wire or carbon placed side by side or angularly towards each other in
vacuo in a glass globe hermetically sealed in the usual way, the wires bringing the
current to each being so connected that one only wire or carbon or loop of wire or
carbon may be lighted, or at pleasure others may be instantaneously added
according as the state of the atmosphere requires, so that the light either from one
incandescent wire or carbon or loop of wire or carbon or from all or from any
number of the wires or carbons or loops within the globes can be utilised at
pleasure.
Dated this 13th day of March 1891.
COMPLETE SPECIFICATION.
Improvements in Illuminating Lighthouses, Beacons, Harbours,
Lightships, and Places where Strong and Variable Lights are
required.
I, JOHN RICHARDSON WIGHAM, of 35 Capel Street, Dublin, Lighthouse
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
In Letters Patent granted to me on the 5th April 1872, No. 1015, I describe a
method of increasing the illuminating power of lighting apparatus as may be
required by the density of the atmosphere, that is in foggy or thick weather, using
for this purpose lamps or burners for the combustion of gas, oil or other kindred

page_text: illuminating agent. My present invention consists in the employment of electricity
for this purpoве.
Heretofore electricity has been used as a lighthouse illuminant only in the form
of are lights to which a twofold objection has been taken 1st. that the arc light is
deficient in red and orange rays which best penetrate fog and 2nd. that the arc
light in itself though exceedingly intense, is very small and thus deficient in the
volume necessary for making an adequate illuminating impression upon fog. My
present invention obviates these two objections, and consists in the use of incan-
descent electric lights, peculiarly constructed to suit lighthouses and other places
requiring similar illumination, which provide the necessary red and orange rays
and the amount of volume useful for fog penetration and illumination. The electric
current may be produced from any form of dynamo or battery, driven by any
motive power, and with or without batteries or accumulators. The incandescent
lamps which I employ, whether in the focus of one lens or tier of lenses or dioptric
refracting apparatus, or in biform triform, quadriform or other multiform applicable
for lighthouse or other illumination, consist of two or more thick wires or carbons
or loops of wire or carbon placed side by side or angularly towards each other in
vacuo in a glass globe hermetically sealed in the usual way, the wires bringing the
current to each being so connected that one only wire or carbon or loop of wire or
carbon may be lighted or at pleasure others may be instantaneously added
according as the state of the atmosphere requires, so that the light either from
one incandescent wire or carbon or loop of wire or carbon or from all or from any
number of the wires or carbons or loops within the globes can be utilised at
pleasure.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
The employment for lighthouse or other purposes of incandescent electric lamps
of variable power, substantially as herein described.
Dated this 12th day of December 1891.
JOHN RICHARDSON WIGHAM.