Improvements in Safety Lamps.
Year: 1890

page_text: Date of Application, 6th Oct., 1890
Complete Specification Left, 6th July, 189! -Accepted, 22nd Aug., 1891
PROVISIONAL SPECIFICATION.
Improvements in Safety Lamps.
We, WILLIAM ALLOTT, and THOMAS FAIRIES, Engineers, both of Chapeltown,
in the County of York, do hereby declare the nature of this invention to be as
follows
Our invention relates to the safety lamps used in mines and other places where
explosive gases are present.
The best forms of such safety lamps are now generally constructed with a thick
plain glass cylinder placed round the flame so as to allow the passage of the largest
possible amount of light. It is found however that the miners using such lamps
suffer after some time more or less from defective sight which is supposed to be
caused by the light from the lamp shining directly upon their
Metal shields
have sometimes been used for the purpose of obviating this defect but have been
found disadvantageous.
eyes.
Our présent invention consists in frosting or roughening that half of the glass
cylinder through which the light shines directly upon the eyes of the miner so as to
break up the light and disperse it in such manner that its direct action upon the
eyes is no longer felt.
Glasses prepared in the novel manner described are extremely simple and their
cost is but very slightly increased as compared with the plain glasses ordinarily
used, whilst they are effective in preventing the ill eflects caused by the latter.
Dated this 4th day of October 1890.
EDWARDS & Co.,
35, Southampton Buildings, Chancery Lane, London,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Safety Lamps.
We, WILLIAM ALLOTT, and THOMAS FAIRIES, Engineers, of Chapeltown in
the County of York, do hereby declare the nature of this invention and in what
manner the same is to be perforined, to be particularly described and ascertained in
and by the following statement, and accompanying drawing that is to say :—
Our invention relates to the safety lamps used in mines and other places where
explosive gases are present.
The best forms of such safety lamps are now generally constructed with a thick
plain glass cylinder placed round the flame so as to allow the passage of the largest
possible amount of light. It is found however that the miners using such lamps
suffer after some time more or less from defective sight which is supposed to be caused
by the light from the lamp shining directly upon their eyes. Metal shields have
sometimes been used for the purpose of obviating this defect but have been found
disadvantageous.
Our present invention consists in frosting or roughening that half of the glass
cylinder through which the light shines directly upon the eyes of the miner so as to
break up the light and disperse it in such manner that its direct action upon the
eyes is no longer felt.
The accompanying drawing is in illustration of our invention, Figure I being a
side view, and Figure 2 a top view of a cylindrical glass to be used round the flame
of the safety lamp, a representing the part of the glass which is roughened or

page_text: obscured more or less so as to prevent the direct rays of light from reaching the
eyes of the person using the lamp.
represents the plain part. The glasses may be either cylindrical, or conical or
other desired shape, and the obscuration may be effected by grinding, roughening
enamelling or otherwise treating the glass for the desired extent of its surface and
either inside or outside.
The glass or the material used for obscuring it may be of any desired colour.
Glasses prepared in the novel manner described are extremely simple and their
cost is but very slightly increased as compared with the plain glasses ordinarily
used, whilst they are effective in preventing the ill effects caused by the latter.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
In safety lamps, the method of obscuring a sufficient part of the glass which
surrounds the flame substantially as and for the purpose described and illustrated.
Dated this 6th day of July 1891.
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicants.