july— sept. 1857.] Portraits with a common Camera. 255 



c 







- a 

 0 















III 

















1 







changed the right one becoming the left 

 and vice versd. Whilst for glass positives 

 it is necessary to use separate glasses, the 

 frame having a smaller central support as 

 below. As the centre of the lenses in taking 

 Stereoscopic pictures is a little above the 

 centre of the Camera, the position of the 

 glass plate must be made to correspond. 



I do not observe that the glasses being 

 parallel instead of converging towards 

 the object makes any perceptible 

 difference in the pictures, but 

 when a table is used to support 

 the Camera, such convergence 

 might be easily given by having 

 a pivot under the front of the Ca- 

 mera and limiting its lateral motion 

 by screws placed as in the accom- 



panying figure F. 



I have found it impossible to 

 get made here the rather com- 

 plicated exposing frame usually 

 described in books on taking 

 Stereoscope pictures, when a 

 system of parallel bars is used 

 on a table to shift the Camera 

 and at the same time to move 

 the collodionized plate. With a 

 Camera constructed as above the 

 parallel frame might be used 



with advantage for groups of fi- 

 SS two suipe shot which allow it to . f 



move easily. gures and distant objects, moving 



the object glass in a direction contrary to that given to the Ca- 

 mera, when the pictures would be in their correct places on the 

 glass. I send enclosed a picture or two which will show that 



