MAGIC LANTERN. 



155 



lens C, is fixed at the inner end of the double tube, and 

 a small convex lens D, at the outer end ; and to the fixed 

 tube C E, there is joined a groove E F, in which the 

 sliders containing the painted objects are placed, and 

 through which they can be moved. Each slider contains 

 a series of figures or pictures painted on glass with highly- 



Fig. 5. 



transparent colours. The direct light of the lamp G, and 

 the light reflected from the mirror M N, falling upon the 

 illuminating lens C, is concentrated by it so as to throw 

 a brilliant light upon the painting on the slider, and as 

 this painting is in the conjugate focus of the convex lens 

 D, a magnified image of it will be formed on a white wall 

 or white cloth placed at P Q. If the lens D is brought 

 nearer to E F, or to the picture, the distinct image will 

 be more magnified, and will be formed at a greater dis- 

 tance from D, so that if there is any particular distance 

 of the image which is more convenient than another, or any 

 particular size of the object which we wish, it can be 

 obtained by varying the distance of the lens D from E F. 

 When the image is received on an opaque ground, as is 

 commonly the case, the spectators are placed in the same 

 room with the lantern ; but for the purposes of deception, 



