The second frame (Fig. 4) consists of a box (6), which, when 

 the camera is applied to processes on paper, is made to receive 



Fig. 3. 



Pig. 



a piece of slate, iron, or glass, which is held tight by a spring at 

 the back : this frame is furnished with a sliding door (c), laying 

 over the top of the camera when raised. A picture four-inches 

 square may be taken in this camera. The lens is usually If inch 

 in diameter, and from eight to twelve inches focus. 



A Camera more especially adapted to the Calotype process, is 

 now constructed on a plan recommended by Mr. Cnndell, whose 

 contributions to the art are very valuable. Two miniscus lenses, 

 each about three inches in diameter, and twenty-four inches in 

 focus, are mounted in a sliding tube, their conjugate foci being as 

 that of a single lens of thirteen inches. These, with an aperture 

 of about 13 inch, and with one or more stops behind the lenses, 

 give a picture beautifully defined. The focus is adjusted, and the 

 prepared paper exposed much on the same principle as the other 

 camera above described. 



The Camera represented Fig. 5 (next page), is a new and very 

 useful article, being made to fold up into the compass of a moderate 



