THE BOOK OP THE LANTERN. 147" 



of any kind of colours, and has some knowledge of the way 

 in which they can be combined to form different tints, will 

 paint a slide very much better than one who is without 

 that knowledge. Should he be quite unused to working in 

 colour, he had best begin by procuring some book upon the 

 general theory of colouring, so that he may understand the 

 difference between a primary, secondary, and tertiary tint, . 

 and may learn how to combine them together. There are 

 plenty of such books to be had, and very often the infor- 

 mation is comprised in some of those useful little manuals 

 on water-colour painting which can be had of most artists' 

 colourmen. I say water-colour painting advisedly, for the 

 art of slide-painting partakes more of that kind of art than 

 any other ; for the reason that it deals with transparent pig- 

 ments. But do not let it be imagined that I recommend 

 vvater colours for the work in hand. I know that some 

 writers have advised their use, and there is more than one 

 nanual which describes how slides can be painted in water 

 colours. The process may possibly have answered under 

 the old conditions, when the majority of lantern slides Were 

 made by the wet process, and when the artist had a layer of 

 collodion to paint upon. But most of my readers will wish 

 to colour their own productions ; and as these will probably 

 consist of gelatine pictures, which any application of water 

 will blister, I will at once reject that method of painting as 

 being inadmissible. 



First, I will make a few remarks with regard to the 

 apparatus required, which is of the simplest description. 

 A retouching desk will make a good easel (see fig. 44), or, 

 failing this, one can readily be made by using a sheet of glass- 

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