160 ' THE BOOK OF THE LANTERN. 



so as to form, a cutting edge. Having opened the compass 

 to the required distance, plant one point on the paper, and 

 gradually with the other cut through the gelatine film. 

 The circular disc so marked out can now be quickly picked 

 away, bit by bit, with the etching-needle. (This needle, 

 by the way, is merely an ordinary needle, bound to a pen- 

 holder by waxed thread.) The same instrument can be 

 used afterwards for picking out effective lights in the fore- 

 ground ; but the great fear is that the beginner should 

 abuse the power thus put into his hands. The touches 

 should be of the most minute description, and the operator 

 should constantly remember that his work, with all its 

 faults, has to be magnified to a very great extent. 



I need hardly point out that a most effective change can 

 be made by showing a landscape, first coloured as a day- 

 light picture, and then dissolving it into the same view by 

 moonlight. This change requires a double dissolving-view 

 lantern, the daylight picture being placed in one lantern, 

 while the moonlight picture is placed in the other, care 

 being taken that both pictures register; that is to say, 

 occupy exactly the same position on the sheet upon which 

 the images are projected. 



But let the beginner not attempt sunsets of the gorgeous 

 order, after the manner of G. M. W. Turner (deceased), 

 until great practice has taught him the different character- 

 istics of his colours. I do not here allude to their tone 

 character, but to the different ways they behave, mechani- 

 cally, when applied to the slippery surface of the picture, 

 and the different media required to coax them into lying 

 flat. He may think that, because he knows how to produce 



