162 LETTERS ON NATURAL MAGIC. 



and the connexion of the levers with the screen, and their 

 interposition between it and the lantern, must interfere 

 with the operations of the exhibitor. It is, besides, suited 

 only to short distances between the screen and the lantern ; 

 for when that distance is considerable, as it must sometimes 

 require to be, the levers K L, K I, K T would bend by 

 the least strain, and become unfitted for their purpose. 

 For these reasons, the mechanism which adjusts the lens 

 D should be moved by the axle of the front wheels, the 

 tube which contains the lens should be kept at its greatest 

 distance from E F by a slender spring, and should be 

 pressed to its proper distance by the action of a spiral 

 cam suited to the optical relation between the two con- 

 jugate focal distances of the lens. 



Superior as the representations of the phantasmagoria 

 are to those of the magic lantern, they are still liable to 

 the defect which we have mentioned, namely, the necessary 

 imperfection of the minute transparent figures when mag- 

 nified. This defect cannot be remedied by employing 

 the most skilful artists. Even Michael Angelo would 

 have failed in executing a figure an inch long with trans- 

 parent varnishes, when all its imperfections were to be 

 magnified. In order, therefore, to perfect the art of repre- 

 senting phantasms, the objects must be living ones, and in 

 place of chalky ill-drawn figures mimicking humanity by 

 the most absurd gesticulations, we shall have phantasms 

 of the most perfect delineation, clothed in real drapery, 

 and displaying all the movements of life. The apparatus 

 by which such objects may be used may be called the 

 catadioptrical phantasmagoria, as it operates both by re- 

 flection and refraction. 



The combination of mirrors and lenses which seems 

 best adapted for this purpose is shown in Fig. 7, where 

 A B is a living figure placed before a large concave 

 mirror M N, by means of which a diminished and inverted 



