LANTERNS AND THEIR MANIPULATION 12 



This is a favourite attachment to the single lantern also, 

 as the screen may be darkened while the slide is instan- 

 taneously changed ; for it may 

 be taken as a universal rule 

 in lantern exhibitions, where 

 'effect' is any object, that the 

 white screen should never be 

 shoivn. To do so makes the 

 slides appear much less brilliant 

 than if no such bright light 

 intervenes. 



The other plan is to cut slits 

 through the sides of the lantern 

 body near the front, so that large 

 pieces of coloured glass, or gela- 

 tine films between two glass 



plates, can be slid in and out of the lantern close to the back 

 of the condensers. This plan is more costly, and weakens the 

 lantern, but has an advantage in not interfering with definition, 

 as the edge of a glass plate in front of the objective does to a 

 small extent. But the ' saving of light ' mentioned in some 

 catalogues only exists in the imagination of the compilers. 

 The apertures in the body are closed by narrow brass doors 

 when not in use. By using one or more sheets of coloured 

 gelatine between glasses, any depth of colour may be had for 

 tinting purposes, with either form of tinter. 



Statuary is best exhibited with all the slides blocked out 

 with black, and dissolved into blue tint, a little of which may 

 be left on with the statue if preferred. 



Slide Effects are described in Chapter X. 



