160 



LETTERS ON NATURAL MAGIC. 



the lens D at the same time brought nearer to E F, the 

 image in P Q gradually increased in size, and therefore 

 seemed in the same proportion to be approaching the 

 ' spectators. 



Superior as this exhibition was to any representation 

 that had been previously made by the magic lantern, it 

 still laboured under several imperfections. The figures 

 were poorly drawn, and in other respects not well executed, 

 and no attempt whatever was made to remove the optical 

 incongruity of the figures becoming more luminous when 

 they retired from the observer, and more obscure when 

 they approached to him. The variation of the distance of 

 the lens D from the sliders in E F was not exactly 

 adapted to the motion of the lantern to and from the 

 screen, so that the outline of the figures was not equally 

 distinct during their variations of magnitude. 



Dr. Thomas Young suggested the arrangement shown 

 in Fig. 6 for exhibiting the phantasmagoria. The magic 



Fig. 6. 



lantern is mounted on a small car II, which runs on 

 wheels W W. The direct light of the lamp G, and that 

 reflected from the mirror M, is condensed by the illumina- 

 ting lenses C C, upon the transparent figures in the opaque 

 sliders at E, and the image of these figures is formed at 



