THE BOOK OF THE LANTERN. 139 



sentation of a November fog. There are several ways of 

 obviating this difficulty. In exposing it before the gas- 

 flame it should, like all thin negatives, be taken several 

 feet distant, so that the time of exposure may perhaps 

 extend to twenty seconds or more. During this time keep 

 the sky portion covered with a piece of card which has 

 been cut in Vandykes all along the edge next the horizon, 

 but do not keep it still, but in gentle movement. This 

 plan gives a clear sky, with the effect of a slight haze over 

 the horizon, an effect, I need hardly say, frequently seen 

 in nature. Indeed, this hazy effect can often be extended 

 to the landscape itself, with the most charming effect of 

 atmosphere which an artist could desire. 



Another plan of treating a thin sky is to furnish it with 

 clouds by the following simple method: Paste over the 

 glass side of the negative a piece of white tissue paper. 

 When this is dry, hold it up to the light, and mark upon it 

 the position of the horizon and the outline of any trees or 

 other objects which may appear against the sky. Now, 

 with a stump and a black pigment (such a pigment for use 

 with the stump is sold by most artists' colourmen, I do 

 not know the name) rub in masses of cloud, taking care 

 that their edges are ill-defined and fleecy. By this means 

 a flat, tame -looking negative can be made to yield a beau- 

 tiful picture. Any water in the composition can be treated 

 in the same way, for it must be remembered that water 

 reflects clouds as well as anything else. Where the sky is 

 dense enough, but contains pin-holes or other blemishes, 

 Bates's black varnish, painted on the plain glass side, is the 

 best remedy; or the faults can be delicately stopped out 

 by ordinary India ink on the film side. Where there is a 



