IMPROVEMENTS IN MAGIC LANTERNS, AND IN THE LAMPS TO BE USED THEREWITH."
Year: 1877

page_text: LETTERS PATENT to Frederic Newton, of Fleet Street, in the City of London,
Optician, for the Invention of IMPROVEMENTS IN MAGIC LANTERNS, AND IN
THE LAMPS TO BE USED THEREWITH."
26
ealed the 20th October 1877, and dated the 18th May 1877.
PROVISIONAL SPECIFICATION left by the said Frederic Newton at the Office
of the Commissioners of Patents on the 18th May 1877.
FREDERIC NEWTON, of Fleet Street, in the City of London, Optician. "IMPROVE-
MENTS IN MAGIC LANTERNS, AND IN THE LAMPS TO BE USED THEREWITH."
Various attempts have been made to burn liquid hydrocarbons in lamps for the
purpose of producing light for magic lanterns, but the tendency to give off smoke
and the great heat produced by the combustion of these liquids have been found great
obstacles to the satisfactory accomplishment of this object.
The hydrocarbon lamps heretofore employed for this purpose have been enclosed
in a casing made of sheet iron, the surfaces of which it was found impossible to
protect from oxidation by the ordinary processes of japanning or tinning, owing to
the heat to which the casing is exposed. The consequence is that the unprotected
surfaces of the casing are liable to become damaged by oxidation if exposed to wet
or to a damp atmosphere. In order to protect these surfaces from oxidation I
coat them with copper, or other suitable metal, by means of the electrotype
process.
.
I find it most convenient to make the casings both of the lamps and the lanterns
of naked iron, and then to coat the surface of the article when made with the
protecting metal, but it will be obvious that the articles may be made of sheet iron
that has been previously coated with the protecting metal.
In order that the combustion of the liquid should be properly conducted the
flame must be enclosed in a close chamber, so that air to support combustion may be
conveyed to the flame only through channels provided for the purpose.
In order to allow the light to pass out of the close chamber to the lenses,
the front end of the chamber is usually provided with a plate or sheet of
... C

page_text: glass. In order that the operator should have a means of examining and watch-
ing the flame, so as to be able to regulate the wick, the back end of the close
chamber is also provided with a sheet or plate of glass, which will also allow
the light to pass to the reflector and be thrown back again. The back and
front glasses complete the close chamber, which is thus made with opaque sides
and top, but with transparent ends. In practice however these glasses are
exceedingly liable to be cracked and destroyed by the great heat to which they
are exposed, and until the damaged glasses are replaced by new ones the combustion
will be very imperfect; in fact the whole apparatus will be thrown out of order, and
cannot be used until new glasses are introduced. The object of this part of my
Invention is to prevent these glass ends of the close chamber from being broken by
the heat. To this end I dispense with the back glass altogether and put a metal
reflector in its place, in the centre of which is made an eyehole provided with a
small glass, through which the operator can see the interior of the chamber. If the
reflector be dispensed with the end of the chamber is closed by a plate of metal,
and a similar hole is made in the centre thereof and closed by a piece of glass, talc,
or other transparent substance, so that the interior of the casing can be seen through
the hole; or the end may be closed entirely, and a sight hole made in any other
convenient part of the lamp.
It has been found in practice that the destruction of the glass ends of the casing
is occasioned by currents of hot air, which are directed by the under side of the top
of the casing in a horizontal direction and made to impinge on the top part of the
glass plate, which, being thereby suddenly overheated at that particular part, will
be apt to crack or fly. In order to prevent this I adapt to the under side of the
cover metal stops, or a metal flange, which will prevent these currents of hot air from
striking or impinging on the ends. The currents of hot air being thus broken up,
divided, or dispersed by striking against the stops or metal flange will not injuriously
act on the glass plates. It will thus be seen that I may safely use a plate of glass
at back, with a reflector behind, if desired.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frederic Newton in the Great Seal Patent Office on the 8th November
1877.
FREDERIC NEWTON, of Flect Street, in the City of London, Optician.
MENTS IN MAGIC LANTERNS, AND IN THE LAMPS TO BE USED THEREWITH."
" IMPROVE-
Various attempts have from time to time been made to burn liquid hydro-
carbons in lamps for the purpose of producing light for magic lanterns, but the
tendency to give off smoke and the great heat produced by the combustion of these
liquids have been found great obstacles to the satisfactory accomplishment of this
object.
In order that the combustion of the liquid should be properly conducted the
flame must be enclosed in a close chamber, so that air to support combustion may bo
conveyed to the flame only through channels provided for the purpose. A chimney
is adapted to the top of the close chamber for the purpose of carrying off the gaseous
productions of combustion and a portion of the heated air.
To allow the light to pass out of the close chamber of the lamp to the lenses the
front end of the chamber is usually provided with a plate or sheet of glass, and in
order that the operator should have a means of examining and watching the flame,
so as to be able to regulate the wick, the back end of the close chamber is also
provided with a sheet or plate of glass, which, will also allow the light to pass to
the reflector, and be thrown back again through the lenses. These back and front
glasses complete the close chamber of the lamp, which is thus made with opaque

page_text: sides and top, but with transparent ends. In practice however these glasses are
exceedingly liable to be cracked and destroyed by the great heat to which they are
exposed, and until the damaged glasses are replaced by new ones the combustion
will be very imperfect and a volume of smoke will be evolved; in fact the whole
apparatus will be thrown out of order, and cannot be used until new glasses are
introduced. The object of the first part of my Invention is therefore to prevent
these glass ends of the close chamber from being broken by the heat. To this end I
dispense with the back glass altogether and put a netal reflector in its place, in the
centre of which is made an eye hole provided with a small glass, through which the
operator can see the interior of the lanp chamber. If the reflector be dispensed
with the end of the chamber is to be closed by a plate of metal, and a similar hole
is made in the centre thereof and closed by a piece of glass, talc, or other trans-
parent substance, so that the interior of the casing can be seen through the hole; or
the end may be closed entirely and a sight hole made in any other convenient part
of the lamp casing.
It has been found in practice that in the ordinary lanterns the destruction of the
glass ends of the lamp casing is occasioned by currents of hot air, which, as they
rise from the flame are directed by the under side of the top of the casing in a
horizontal direction, and made to impinge on the top part of the glass plate, which,
being thereby suddenly overheated at that particular part, will be apt to crack or
fly. In order to prevent this I adapt to the under side of the lamp cover, and at
the open end where the glass plate is placed, metal stops or a metal flange, which
will prevent these currents of hot air from striking or impinging on the glass, ends,
as heretofore. The currents of hot air being thus broken up, divided, or dispersed
by striking against the stops or metal flanges will not injuriously act on the glass
plates. It will thus be seen that I may safely use a plate of glass at back, with a
reflector behind, if desired. In order still further to cause the currents of heated
air to diverge from the horizontal line I make one or more holes in the top of the
casing, just behind the glass. The air, by rushing in from the outside, mingles with
the heated currents of air and breaks them up.
In the accompanying Drawing,-
Fig. 1 is a longitudinal vertical section of a magic lantern with a lamp constructed
according to my improvements; Fig. 2 is a transverse vertical section taken in the
linc 1, 2, of Fig. 1, and shewing an end view of the lamp.
Fig. 3 is an external side elevation of the lamp complete, but removed from the
lantern casing.
Fig. is a plan view of the lamp with the upper part and deflecting plate
removed.
.
Fig. 5 is a sectional plan view of the lamp with the deflecting plate in its
place.
Fig. 6 is a plan view of the wick holder drawn full size, and Fig. 7 is a trans-
verse vertical section of the same, also drawn full size, and taken in the line 3, 4, of
Fig. 6.
The oil chamber a forms the base of the lamp and receives the wick, as shewn at
Fig. 1. The wick holder b, b, is made double, in order to receive two wicks, and the
wick tubes are inclined upward, and are set at an angle to each other, as shewn at
Figures 6 and 7, as is sometimes the case in lamps of this class. At the top outer.
edges of the wick tubes are horizontal flanges b¹, b', seen best in Figures 6 and 7,
extending the whole width of the wick, for the purpose of preventing the currents
of air which rise up through the perforated metal plate c* in the lamp from
injuriously impinging on the outer sides of the flames. The inner sides of the wick
tubes do not require this protection, as the inclination of the side will prevent the
air from injuriously affecting the flame. The space between the wick tubes is
closed by a curved piece of perforated metal c. A flat piece of perforated metal c*
will also prevent any puffs of air from the lower part of the lamp from affecting
the flame.

page_text: A deflecting plate e of the shape shewn in the Figures, and with a slit or hole
made in its upper part (for the frame to pass through) is adapted to the burner, for
the purpose of steadying the flame and causing the air to impinge thereon in a
proper manner, as is well known, in lamps of this kind. The reflector fis hinged
at its bottom edge to the back part of the lamp casing, and is held in place by a
spring clip fabove; it is provided at its central part with an eye hole f², which is
closed by a piece of glass, as shewn in the Drawing. The front end of the lamp
casing is closed by a flat glass plate g, which is held in place in the usual manner
by the side clips g, gl, and the upper spring clip g².
In order to prevent the currents of heated air from the burner from being
deflected by the curved top plate h of the lamp casing, and thereby made to strike
against the upper part of the glass plate g, a projecting flange i, i, is made ali
round the end of the casing, as seen best in Figures 8 and 9, which are end and
sectional views of this part of the lantern drawn full size; the hot currents of air
are thus diverted and prevented from striking against the glass. In order still more
to break up the currents of heated air at this part small holes are made in the top
of the casing to admit air to the interior, as indicated by the arrows in Figures 1
and 9. By constructing the several parts in this manner a breakage of the glass
plates by the currents of heated air or gases is effectually prevented. The lamp
thus constructed is provided as usual with a metal chimney j, and is enclosed in the
lantern case, l, as shewn at Figures 1 and 2. A considerable amount of heat is
radiated from the external sides of the lamp casing; and in order to carry off this
heat I make large openings, , Fig. 1, at the front and back of the casing, so as
to admit air freely to the interior and allow it to pass up the spaces between the
casing of the lamp and the casing of the lantern, which is left open at top, so as
to provide a wide space ², ², all round the chimney j of the lamp, for the exit of
the heated air or gases. By this means the interior of the lantern is properly
ventilated, and is therefore kept moderately cool.
It is also important to keep the condensing lenses of the lantern as cool as
possible, and to this end I construct around the tubular socket (which holds them in
place in the lantern) a box or annular space m, m, Fig. 1, which is perforated
all round, so as to freely admit the air to circulate around and keep the lenses
cool.
The lantern casing is provided at back with a door *, Fig. 1, which is hinged at
top to the body, so that it may be lifted up, as indicated by the dotted lines, when
it is desired to introduce the lamp, which is made to slide in grooves fixed on the
base of the lantern casing. As however it may soinetimes be required to use the
oxyhydrogen light in this lantern, and as the apparatus connected with such a
means of illumination cannot be conveniently manipulated from behind, I adapt to
the side of the lantern casing a second door **, as shewn at Fig. 2. By thus
providing the. lantern casing with two doors, one at the rear and one at the side, the
lantern can be used either for oil or for the oxyhydrogen light, according to the
particular purpose or kind of exhibition for which it is to be employed.
Having now described my Invention of "Improvements in Magic Lanterns, and
in the Lamps to be Used therewith," and having explained the manner of carrying
the same into effect, I claim as the Invention secured to me by Letters Patent as
aforesaid,
The construction of parts herein shewn and described for the purpose of keeping
the several parts of the lantern and lamp cool, and preventing the heat or currents
of heated air from impinging upon and breaking the glasses, as above described.
I claim particularly the projecting flange or stop i, i, for deflecting the currents of
heated air, and the holes made in the top of the lamp casing for the admission of
cold air from the outside, so as to break up or disperse the currents of heated air, as
and for the purposes herein set forth.
I further claim the adaptation of the horizontal flanges b¹, b', to the top of the
wick tubes, as and for the purpose herein set forth.

page_text: I also claim closing the back part of the lamp casing by means of the metal
reflector instead of a glass plate, as heretofore, as and for the purpose herein set
forth.
In witness whereof, I, the said Frederic Newton, have hereunto set my hand
and seal, the Second day November, in the year of our Lord One thousand
eight hundred and seventy-seven.
FREDERIC NEWTON. (L.S.)