iv PREFACE. 



the various interesting portions of the Magic Lantern 

 Held in general, as well as to the Sciopticon in particular. 



It treats of the Optical Image without a lens, with 

 a lens, in the camera obscura, in the eye, in the photo- 

 graphic camera, and on the screen ; of the peculiarities 

 of lenses, and the corrections required hy lenses; of the 

 peculiarities of the Sciopticon, and its construction and 

 management; of dissolving views, phantasmagoria, and 

 the ghost ; of lantern slides in all their variety ; of photo- 

 graphing slides by the wet-plate process, b}^ the dry-plate 

 process, by Marcy's Photographic Printing Apparatus, 

 by the Sciopticon, and other processes; of how to paint 

 slides, and of ho\v to perform chemical experiment- 

 to which is appended a catalogue, arranged to assist 

 purchasers in making satisfactory selections. 



Thus this Manual may take the place of private cor- 

 respondence to a considerable extent, allowing in let- 

 ters more space for business, and tor an interchange of 

 new ideas, with a view of making the Manual in subse- 

 quent editions more interesting, and the Sciopticon more 

 useful. 



It was at first my intention to give space to the sub- 

 ject of chemical lights, but reflect ing that in this direc- 

 tion there is no lack of printed matter, and that the in- 

 terest felt in the Sciopticon is owing mainly to its giving 



