MAGIC LANTERN. 85 



The method recommended by Dr. Young for 

 pulling out and pushing in the object lens D, ac- 

 cording as the lantern approaches to or recedes 

 from the screen, is very ingenious and effective. 

 It is, however, clumsy in itself, and the connexion 

 of the levers with the screen, and their interposi- 

 tion 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 KL,KI,KT, would bend by the 

 least strain, and become unfitted for their pur- 

 pose. 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 conjugate focal distances of the lens. 



Superior as the representations of the phantas- 

 magoria are to those of the magic lantern, they 

 are still liable to the defect which we have men- 

 tioned, namely, the necessary imperfection of the 

 minute transparent figures when magnified. 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 

 transparent varnishes, when all its imperfections 

 were to be magnified. In order, therefore, to 

 perfect the art of representing 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 



