t THE BOOK OF THE LANTERN. 123 



other objects which stand against the sky, should have a 

 broad margin painted round them in Chinese white, leaving 

 the main body of the sky to be blocked out with black 

 varnish in the negative itself. 



I have done excellent work with Ross's portable sym- 

 metrical lens No. 3 which has a focus of 5 inches. Of 

 course, other lenses will do well for copying, but if of 

 longer focus, the camera must have an extending front 

 fitted to it. Very few cameras pull out long enough to 

 photograph a very near object, unless a short focus lens is 

 employed. As a guide to exposure, I may mention that 

 in copying wood-cuts and photographs with the above- 

 named lens, and using a fairly-rapid gelatine plate, it 

 averages 17 seconds with stop No. 4. It is as well to focus 

 with full aperture of the lens, and to insert the stop just 

 before exposure. One more hint. It is sometimes very 

 difficult to sharply focus a soft photograph which has no 

 sharp lines in itself. The difficulty is obviated by affixing 

 to the middle of the copy any little piece of printed matter, 

 wetting it with the tongue for that purpose. Only be 

 careful to remove it before exposure, or your negative will 

 faithfully record the little dodge. 



It would seem a very simple matter, to one who has not 

 tried it, to fasten a picture upon a wall in a good light, 

 stand the camera on its tripod in front of that picture, and 

 proceed to copy it. But difficulties crop up when we want 

 to reduce that picture to a certain size, and to keep the 

 camera square with the copy, so as to prevent distortion. 

 With head beneath the focussing cloth, the struggle to 

 adjust the tripod legs is quite distressing. I myself found 



