122 THE BOOK OF THE LANTERN. 



latter cases be so much extended that the exposure must 

 be proportionately increased. 



A picture under glass will seldom give a good result, 

 for the surface will take up reflections from surround- 

 ing objects, which may not perhaps be noticed on the 

 focussing screen, but which will most surely become dis- 

 agreeably evident in the negative. A highly glazed 

 albumenized print is objectionable for the same reason, 

 but can be generally coaxed into a position in which no 

 mischief of the kind is apparent. Steel engravings have no 

 gloss, but they seldom make good pictures for the lantern 

 screen, their details being too fine. A first-class wood 

 engraving is far better for the purpose, and as its value is, 

 as a rule, not very great, it can be judiciously touched up 

 before being photographed. Perhaps the artist of such a 

 picture would be horrified at his work being thus interfered 

 with, but the touching up indicated is quite legitimate. 

 Let me further explain my meaning. Suppose that in one 

 of our illustrated periodicals there is a representation of 

 some current event which we want for our lantern. If it 

 is an interior view, it will probably require no doctoring. But 

 if a landscape, or a group of figures with a sky back- 

 ground, then certain parts should be suppressed. The sky 

 is not white, but consists of a number of parallel lines with 

 clouds interspersed ; effective enough in the print, but not 

 suitable for reproduction in an enlarged form. These lines, 

 which seem to mingle so well, giving the effect of a general 

 soft " tint," will on the lantern sheet look like what they 

 really are a series of detached bars right across the picture. 

 To get rid of these lines, the outline of the figures, and 



