88 



LETTEES ON NATURAL MAGIC. 



is shown in Fig. 8. where a b is the inverted image 

 formed by a concave mirror, ABC a prism with 

 a small refracting angle BCA, placed between 

 ab and the lens LL, s a small opaque screen, 

 and A B the figure with its head detached. A 

 hand may be made to grasp the hair of the head, 

 and the aspect of death may be given to it, as if 

 it had been newly cut off. Such a representation 

 could be easily made, and the effect upon the 

 spectators would be quite overpowering. The 

 lifeless head might then be made to recover its 

 vitality, and be safely replaced upon the figure. 

 If the head A of the living object A B, Fig. 7, is 

 Fig. 8. 



covered with black cloth, the head of a person or 

 of an animal placed above A might be set upon 

 the shoulders of the figure A. B by the refraction 

 of a prism. 



When the figure a b, Fig. 8, is of very small 

 dimensions, as in the magic lantern, a small prism 

 of glass would answer the purpose required of 

 it ; but in public exhibitions, where the image a b 

 must be of a considerable size, if formed by a 

 concave mirror, a very large prism would be 



