38 Cincinnati Society of Natural History. 



are much over-timed it is difficult to manage them, and probably 

 the best plan is to lay them aside and make another exposure. In 

 fact, after one has some experience in making slides, this will be 

 found the best remedy for a faulty plate of any kind. It is so easy 

 to make a good one that it hardly pays to waste time over one 

 which has come to grief. 



A much stronger light is permissible for developing lantern 

 slides than for ordinary negative work, as owing to the comparative 

 slowness of the plates, even a tolerably strong orange light is safe. 

 This, of course, adds much to the comfort of the operator, and 

 enables him to proceed more rapidly. 



Scrupulous neatness in all photographic work is always well 

 repaid in the results, but in none more so than in the making of 

 these, probably the finest and best ot all photographic productions. 



