CHAPTER XIX. 



PRACTICAL HINTS TO THOSE WHO EMPLOY THE LANTERN FOR 

 SCIENTIFIC DEMONSTRATION, OR FOR ENTERTAINMENTS IN 

 THE DRAWING-ROOM OR LECTURE-HALL. 



j 1ST the foregoing pages I have endeavoured to 

 describe the best methods of manipulating the 

 lantern ; and I hope that I have done so in such 

 a manner as to enable all my readers readily to under- 

 stand the working of this beautiful instrument. I feel 

 convinced that if my * instructions are carefully followed 

 all will go well, at all events, in the apparatus depart- 

 ment. But the best instrument is no good unless the 

 lecturer be an efficient showman and speaker. Unfor- 

 tunately many essay the task of lecturing who are physi-, 

 cally unfit for it. There are many good-natured people in 

 the world who will undertake, very often for some charity, 

 to act as lecturer in a school-room, the slides being 

 borrowed from some optician with a printed lecture fitted 

 to them. This good-natured man will take up the work 

 without much thought or consideration, and the result is 

 too often a very bungling performance. A man may have 



