62 SCIOPTICON MANUAL. 



exposed in the camera, carried into the dark-room, and 

 developed, fixed, and toned. 



If many positives are to be made from negatives of 

 different sizes, it will be found convenient to arrange 

 two cameras front to front (as will be seen in Fig. 23), 



. 23. 



one camera having a lens in position with ground-glass 

 No. 1 ; the other having the lens and ground-glass re- 

 moved, and the negative that is to be copied placed in 

 the position of ground-glass No. 3. The cameras, for 

 convenience, can be closely joined together by screwing 

 strips of wood upon each, which prevents any change 

 of position when focused. By turning the rack-work 

 upon each box, the picture upon the ground-glass can be 

 made of any size. 



This plan of using two boxes will be found to give 

 perfect satisfaction; the negative and sensitive plates 

 are always on the same plane, and the adjustment for 

 difference of size made in a moment. It is only for 

 convenience of manipulation, that the writer advocates 

 this arrangement, for excellent positives can be obtained 

 by using one camera, and placing the negative to be 



