136 



THE BOOK OF THE LANTERN. 



into the alum tray ; and so on, until perhaps a couple of 

 dozen plates have been treated in the same way. I then 

 light my gas-lamp, mix up a tray of fresh hypo, large 

 enough to accommodate half a dozen plates at a time, and 

 proceed to fix my plates. They fix rapidly, and as fast as 

 they are done, back they go into the weak alum solution, 

 until, when the batch is finished, I proceed to wash them. 

 This I do by placing them in a metal rack (see fig. 42), 

 and changing the water occasionally during an hour or so. 



FIG. 42. 



GENERAL CONSIDERATIONS INTENSIFYING AND MOUNTING. 



Hitherto I have said nothing with reference to the best 

 kind of negative for lantern- slide making ; the worker will 

 find out, after a few trials, that some of his negatives will 

 yield, without much trouble, a first-class result, whilst others 



