DEMONSTRATIONS IN PHYSICS 



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fig. 109, or two small glass plates inclined together and also 

 fitted at the top in a strip of wood (fig. 110), in a small tank of 

 water placed on the lantern stage. The tank may be of any 



FlO. 109 



FIG. 110 



convenient shape, and the simple form shown in fig. Ill, 

 where the glass plates are mounted in a wooden frame to fit 

 the usual slide-stage, will answer perfectly well. The reverse 



FIG. Ill 



Fro. 112 



phenomena shown between glass and such a fluid as mercury, 

 are projected by a small apparatus like fig. 112, about double 

 the size there shown. 



