216 PREPARATION OF LANTERN SLIDES [Cn. VIII 



334. Mounting lantern slides. In the original method, 

 which is still followed to a certain extent, each slide was mounted in 

 a w r ooden frame that is, each slide had its own carrier which was 

 put in place when it was to be shown (fig. 15). 



For teaching and for many other purposes glass lantern slides 

 arc not now put in separate wooden frames, but are covered with a 

 clear glass (cover-glass) of the same size and the two bound 

 together by adhesive paper. They are far less bulky in this way of 

 mounting, although they are not as well protected as in the earlier 

 form. 



In mounting them the slides are thoroughly dried, then some 

 form of opaque mat or mask is put over the picture on the picture 

 side of the transparency or negative. There are on the market 

 masks or mats of various shapes and sizes of opening. These may 

 be used or masks may be made by using strips of black paper. 



When the mat is in place a cover-glass of exactly the same size 

 as the lantern slide is thoroughly cleaned and placed over the 

 picture surface of the slide. Then a narrow strip of adhesive paper 

 is put all around the edge. This holds the slide and the cover in 

 position, and prevents the sharp edges of the glass from cutting the 

 fingers when handling the slides. The mat not only cuts out any 

 part which is not to be shown, but it separates the cover-glass 

 slightly from the picture and prevents rubbing or other injury to it. 

 The size and shape of the opening in the mat to give the best effect 

 depends upon the picture or other matter on the lantern slide. The 

 mat is a kind of frame and like any other frame it should be suited 

 in form and size to the object to be shown. 



335. Marking or "spotting" the mounted slides. As 



pointed out in Chapter I ( 23) each slide should have some kind of 



Kodak Company recommend that the film slides be used only with a magic 

 lantern having a water-cell (fig. 2, 3). 



Furthermore, even if non-inflammable film were used, it would not do to 

 leave those slides in a lantern without a water-cell too long for the heat would 

 make the celluloid buckle and get out of shape or char it, although of course 

 it would not be set on fire. 



The lightness rind small space 1 required for such slides arc of great advantage, 

 but their limitations are so great that for the general, and rough usage of ordi- 

 narv lantern slides they are not so well adapted as glass slides. 



