Untitled

54 MODERN MAGIC LANTERNS.
being in the case of the limelight, which is invariably
employed with them, a dissolver or tap for simultaneously
lowering one light and raising the other. They should be
so built that one lantern
can be separated from
the rest and used by itself
when necessary. The
fronts of these must,
moreover, be fitted in such
a manner that they can be
inclined one to the other,
and so adjusted that the
picture shown by each
lantern falls in exactly
the same place upon the
Fig. 42. DISSOLVER FOR OIL LAMPS.
screen.
The lantern front should
consist of a stout brass
plate securely clamped to the woodwork by its four corners,
carrying on one side of itself the condenser and on the other
the receptacle for the slides or for the slide-carrier, and a
telescopic tube which bears at its end the objective.
Immediately in front of the condenser
is a gap, open at both sides
and sometimes at the top, in
which the slide to be shown is
inserted. Slides are used in two
forms, the slide pure and simple,
Fig. 43, composed of two glasses,
each 3i inch by 3i inch, bound together
by their edges, or this slide
is mounted in a wooden frame,
Fig. 44. In the latter case it is
held in the lantern by two springs,
one of which is shown in Fig. 1,
which press it up against the
- - - - - *L. ----- -
Fig. 43.
AN UNFRAMED SLIDE,
SPOTTED.
lantern front. To show dissolving views and effect slides
properly, they should always be mounted, and a brass
runner with a stop inserted in the gap of the lantern. The
mount must then be carefully adjusted, so that when the
4*
THE LANTERN BODY. 55
mounted slide is inserted and pushed right up to the stop,
the picture is exactly in the required position on the screen.
The unmounted slides are held in what is called a
carrier, of which there are many patterns. The simplest
Fig. 44. A FRAMED SLIDE.
form of carrier is shown in Fig. 45. This consists of
two horizontal strips of wood held apart by two vertical
pieces ; on the inner sides of the longer pieces are
Fig. 45. SIMPLE FORM OF CARRIER.
grooves along which a slide 31 x 31 will slip. This form
has been improved by making the length of it such that on
pushing a second slide in until the finger is stopped by the