22 



THE BOOK OF THE LANTERN. 



already pointed out. So the suggestion was made that a 

 small lens should be interposed between the light and the 

 condenser. This was done with a wonderful gain in the 

 performance of the old lanterns. Fig. 14 will show how 



FIG. 14. 



the additional lens brought this improvement about. Many 

 other forms of condensing lenses have from time to time 

 been suggested and experimented with, some of these em- 

 ploying three or more combinations. But these various 

 patterns, although one or two of them seem very promising 

 in form, have not been taken in hand by makers generally, 

 possibly on the score of expense, and probably owing as 

 much to that hesitation and laziness common to human 

 nature, which keeps us all to a well-beaten track. 



But a few years ago the question of lantern lenses was 

 revived by a paper read by the late Mr. J. H. Dallmeyer 

 before the Photographic Society of Great Britain. The 

 reader of this excellent contribution to the subject, explained 

 in the first instance that a well-known worker with the 

 lantern h^cl called his attention to the great want of more 



