IMPROVEMENTS IN OUTSIDE REFLECTING LANTERNS
Year: 1857

page_text: application for Letters' Patent was not given within the time prescribed
by the Act.)-
PROVISIONAL SPECIFICATION left by Thomas. Boyle at the Office of
the Commissioners of Patents, with his Petition, on the 20th January
1857.
I, THOMAS BOYLE, of 1, Pilgrim Street, Ludgate Hill, in the City of
London, do hereby declare the nature of the Invention for "IMPROVEMENTS
IN OUTSIDE REFLECTING LANTERNS," to be as follows:-
I first make a concave circular reflector, either in the form of a curve, or
with straight sides converging to a point in the centre, as shewn in my Patent
for "improvements in reflectors," granted to me in 1854 (27th December,
No. 2728). I make this reflector of plated metal or any other suitable
material, but I prefer silvered glass, used in the manner shewn in my Patent
above mentioned, employing of course straight or flat pieces of glass in the
straight-sided frames, and bent or curved pieces in the curved frames. To a
reflector, so made, I add on the exterior of the frame a chimney or funnel of
the ordinary construction, communicating with a suitable aperture in the
reflector, two iron-wire pins or prongs at the back to fit the corresponding
sockets in the gas pendants at present in use, and a transparent front of either
clear, or ground, or colored glass. It is in the adaptation of this transparent
glass front to a circular reflector, to be used at an angle in the manner of the

page_text: ordinary outside shop window lanterns, that the peculiar advantage and merit
of the present Invention consists.
In all the attempts that have hitherto been made to render circular lanterns
available for outside use it has been found necessary to fill up the space
between the outer rim of the reflector proper and the circular glass door with
a band of other material than glass, usually perforated copper or other metal,
owing no doubt..to the expense and difficulty of procuring a glass cylinder
of the necessary size and shape for the purpose. I overcome the difficulty
by filling up this space with separate slips of flat transparent glass, arranged
side by side in suitable grooves constructed in the frames for their recep-
tion, and thus forming at little cost a transparent band of glass, through
which the light passes freely all around, instead of being obstructed, as
in the case of the metal bands, by the opaque spaces of metal remaining
between the perforations. I produce a similar effect, as far as regards
the non-obstruction to the passage of the light, by means of curved or
bent pieces of glass, arranged in the same manner as the flat pieces, and
uniting in the whole to form the circle; but as these would necessarily be more
expensive, less readily replaced if broken, and less easily adapted to the varying
sizes and shapes of lanterns, I prefer in practice the use of flat pieces.
The forming of this circular band of glass in the manner described possesses
another advantage, in the facility which it offers for the proper ventilation of
the lantern. The pieces of glass may either be fitted quite close to each other
so as to exclude air altogether, or be situated more or less apart to allow
sufficient draft to the burner for the purposes of combustion, and yet preserve,
as nearly as possible, an equilibrium of temperature between the interior and
exterior atmospheres. This will prevent the breakage of the glass chimneys,
and the consequent burning and destruction of the lantern, annoyances hitherto
greatly complained of, and inseparable from the use of almost all the outside
lanterns now made. The pieces of glass in the top half circle may be made to
overlap each other, and thereby throw off rain; or this portion of the circle may
be made reflective, preventing the passage of the light upwards, and adding so
much to the power of the lantern.
Another improvement in my new lantern is the manner in which the door is
hung. It is hinged on to the side instead of to the top, and opens and shuts
after the manner of a circular clock-door face, thus facilitating the doing of
anything within the lantern, such as cleaning, repairing, &c.
A further improvement is the ease with which my new lantern is placed on
or taken off the fitting.
.

page_text: A circular aperture is left in the bottom of the circular glass band, through
which, in fixing the lantern on to the pendant, the chimney and burner are
admitted into the interior of the lantern without opening the door. Thus, the
pendant being ready in its place with its burner and chimney glass on, and the
gas slightly alight, the simple act of dropping the pins of the lantern into
the sockets of the fitting completes the preparations necessary for its imme-
diate use.