Improvements in Magic or Optical Lanterns.
Year: 1889

page_text: Date of Application, 16th Aug., 1889
Complete Specification Left, 14th May, 1890-Accepted, 19th July, 1890
PROVISIONAL SPECIFICATION.
Improvements in Magic or Optical Lanterns.
I JAMES HENRY STEWARD 406 Strand London Optician do hereby declare the
nature of this invention to be as follows:-
Improvements in Magic or Optical Lanterns, consisting, first, of an improved
method of adjusting the fronts & lenses (the optical system) and 2nd, improved oxy
hydrogen lime light jet for the more perfectly centring, adjusting & controlling the
light.
The fronts are designed to secure more steadyness & greater perfection when
focussing & adjusting the lenses. It consists of a racked bar extending from the
lantern stage plate, or lantern body to a skeleton framework supported on the foot
board or base of lantern in front and connected with it in such a way that it can be
moved up or down & sideways to get the exact adjustment for the required axis of the
optical system, and correct inclination.
The optical system consists of the ordinary condenser & front lenses or objective,
the latter being mounted in tubes, & generally connected to the stage by means of
telescopic tubes so that a shorter or longer focus objective can be used at will. In the
improvement the jacket in which the objective is mounted is fixed by a collar or flange
finishing in a pinion fitting to the racked bar, a milled head pinion working the same
along a racked bar to the necessary distance to get the focus with either say 6. 8. 9.
10. 12 inches or longer focus objective. The skeleton supporting framework consists
preferably of a parallelogram of brass tubes or bars with cross bars for either two or
three front tubes to come through the openings or allow the rays to come through
when the lantern has a light inside, the racked bars being connected to the cross bars
of framework by an adjustable fitting working vertically & laterally. The improved
jet consists of the ordinary tubes & tape which convey the oxygen & hydrogen gases
seperately to the mixing chamber or point of ignition but have in addition improved
method of moving the whole to or from the condenser by a screw adjustment to a
supplemental slide or tray attached to the ordinary supporting tray; also a quick-
threaded screw for raising and lowering the jet, so placed on the tray that the jet
balances & by means of two pillars one in front & one behind the adjusting screw
instead of one as usual at back it works up & down with perfect ease & smoothness.
The fittings of the pillars have clamp screws attached for rigidly fixing after once the
proper position is obtained. A lateral slide with tangent screw fixed to the foundation
slide or tray permits of the movement of jet sideways and so ensures a fine adjustment
for the light laterally. In addition to the above the following adjustments can also
be and are adapted for special purposes, viz.-a supplemental slide actuated by a screw
for the gallery holding lime cylinder & working on the gas tubes of jet, to carry the
lime to, or from the nipple of jet; also a shut-off plug that passes through both tubes
& closes the orifices of same and prevents the gas passing with the exception of a
minute portion of hydrogen just to keep the flame alight. This can be turned in
several ways but preferably it is done by means of a rod extending to outside of
lantern with pinion working in a toothed wheel attached to head of plug at other end.
The advantage of this is that having once adjusted the hydrogen and oxygen gases by
means of the ordinary taps to give the best light, the gas can be turned off or turned
on as often as required and yet get the same light as at first. hv simply turning the
rod attached to plug as described.
Dated this Sixteenth of August 1889.

page_text: COMPLETE SPECIFICATION.
Improvements in Magic or Optical Lanterns.
JAMES HENRY STEWARD 406 Strand London Optician 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 :-
Improvements in Magic or Optical Lanterns consisting of, first, an improved method
of adjusting the fronts and lenses (the optical system) and second, improved oxy
hydrogen limelight jet for the more perfectly centering, adjusting, and controlling the
light.
The lantern front is designed to secure more steadiness and greater perfection when
focussing and adjusting the lenses. It consists of a racked bar E figs. 1 & 7 extending
from the lantern stage plate For lantern body G to a skeleton framework C. CC
supported on the footboards or base of the lantern, in front. The rack bar may be
connected with the framework in such a way that it can be moved up or down and
sideways to get the exact adjustment for the required axis of the optical system and
correct inclination of the front, B. B¹ or fixed as desired A. The optical system
consists of the ordinary condenser and front lenses or objectives-the latter being
mounted in tubes and generally connected to the stage by means of telescopic tubes
so that a shorter or longer focus objective can be used at will, but they may be fitted
in tubes of various length that shall slide or fit in one of large diameter capable of
allowing the rays to properly emerge when the lenses are in focus.
large tube is made to adjust & preferably by rack & pinion as usual in objectives when
A portion of this
focussing for different slides of varying thickness.
In the improvement the jacket in which the objective is mounted is fixed by a collar,
crutch, or flange, finishing in a pinion fitting, to the racked bar, a milled head pinion
working the same along the racked bar and so drawing out the telescopic tubes to the
necessary distance to get the focus with either say 6, 8, 9, 10, 12 or longer focus
objective. If the tube is solid instead of telescopic then the crutch, flange, or collar
can be attached direct to the supporting framework C by means of vertical & lateral
adjustments as shewn in fig. 3. The skeleton supporting framework consists pre-
ferably of brass or metal tubes or bars with cross bars to each front employed, and
arranged so that the whole of said front can be held firm at a normal position as at A
or adjusted at and to an inclination (B) or declination (BI), as may be required when
two or three fronts are employed for projecting pictures, photographs, or optical
effects. By this means ray's of light can come from the lens through the openings
and the angle can be arranged so that they produce discs on the screen that exactly
superimpose, and the fronts can then be clamped by the locking nuts.
front only is employed as in a single lantern for class demonstration, or for optical
or photographic projections the connecting bar can be either fixed solid as at A. or
adjusting as at B. B'. The enlarged drawing of the latter fig. 2 shews the screws
and locking nuts for vertically moving the bar & with it the front, and for clamping
it, also the side pushing screws for lateral adjustment & fixing. In the case of the
front tube not being telescopic the horizontal bar in the skeleton supporting frame is
made to move laterally or an attachment in preference is fixed to it, which is driven
by the screw A passing through block B & then clamped by screw nut C. as shewn
in figure 3. The supporting crutch or collar F is moved vertically as shewn at i) by
means of screw washers E. E. up or down-one being released and the other
clamped.
When one
The improved oxy hydrogen lime light jet consists of the ordinary tubes & taps
which convey the oxygen and hydrogen gases seperately to the mixing chamber or
point of ignition but has in addition an improved method of moving the whole to or
from the condensing lenses of lantern by means of a screw adjustment (C¹) figs. 4.
5. 6. to a supplemental slide (c) or tray B₁ attached to the ordinary supporting tray K.
Also a quick threaded screw A fig. 4 for raising & lowering the jet so placed on the
tray that the jet balances & by means of two pillars H. H. one in front and one

page_text: behind the vertical adjustment instead of one as usual at the back only, the jet works
up & down with perfect ease and smoothness. This screw can be either actuated by a
milled head directly above as shewn at A fig. 4 or by an arm geared to it at right
angles and extending to the outside of lantern body, or it may be replaced by a racked
pillar (a), with a pinion A as shewn in fig. 5.
Any fine mechanical motion will answer the improvement being the rigidity given
to the jet & the steadiness of the movement by the use of two pillars H. H. These
pillars are generally supplied with clamps G. G. but they are not indispensible as
unless great force is used either the screw or rack will support the jet after once it is
set in true central or the desired position without shifting. A lateral slide or stage B¹
with tangent screw B shewn in plan in fig. 6 fixed to the foundation plate, slide,
board, or tray permits of the movement of the complete jet sideways and thus ensures
a fine adjustment for the light laterally. This tangent screw can be turned by the
milled head B fig. 4 or actuated from outside the lantern by substituting the bevelled
wheel & rod B figs. 5 & 6. In addition to the above the following adjustments can be
and are adapted for special purposes, viz. :-A supplemental slide (figs. 4. 5) actuated
by a screw D. for the gallery holding lime cylinder L & working on the gas tubes of
jet. Also a single plug shut off F that passes through both gas tubes & closes the
orifices of same to prevent the gas passing with the exception of a little (minute
portion) of hydrogen just to keep the flame alight. This is preferably turned by
means of a rod F extending to the outside of lantern body with pinion at the other
end working in a crown wheel attached to the plug f. in which the bye pass groove is
cut. The advantage of this is that one plug only goes through both tubes and so acts
on both at once, hence having once adjusted the hydrogen & oxygen gases by means
of the ordinary taps 1. to give the best light, the gas can be turned off or turned on
as often as required & yet get the same light as at first, by simply turning the rod
attached to plug as described.
E is the ordinary limeturning arrangement.
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 :-
1. The method of supporting the optical fronts of magic lanterns and dissolving
view apparatus from an independent support or framework as described.
2. The method of adjusting the angle of lantern fronts by means of vertical &
horizontal movement in this support as described & figured.
3. The method of using a racked bar pinion, with milled head & fitting for drawing
out one, two, or more tubes of lantern front.
4. The use of two uprights or pillars for the support of and the method of balancing
limelight jets.
5. The lateral adjustment to the tray or supporting slide, the movement mechanically
of the tray to & from the lenses, and the vertical adjustments to jets substantially as
described.
6. The single plug cut off arrangement to control the gas, passing through both the
oxygen & hydrogen tubes & the method of turning same.
7. A Magic or Optical Lantern, or dissolving view apparatus substantially as
described.
8. An oxy hydrogen limelight apparatus substantially as described.
Dated this Thirteenth day of May 1890.