THE BOOK OF THE LANTERN. 



15 



two rows its capabilities are much increased, for the organist 

 can use them alternately in contrast with one another, or 

 can combine them. With three claviers, his powers are 

 once more amplified, and he can introduce those changes 

 of musical colour for which our language provides no 

 descriptive word. So it is with the lantern. If it have 



FIG. 9. 



but one optical system the operator can only use it as a 

 means of showing simple pictures or diagrams. If it have 

 two systems he can produce the popular dissolving views ; 

 and if it be provided with a third set of lenses, he can 

 mingle with the views shown those " effects," as they are 

 called, which are so welcome to an audience of young 

 folk, and very often to children of a larger growth. 



