THE COMPONENTS OF A CEMENTED COMBINATION LENS. 17 



You will notice that the diverging meniscus turns the (i) 

 into an (e), following a plano-concave as I hinted above, only 

 making the s into an L. 



These examples will be sufficient to make anyone acquainted 

 with the method I employ. 



I have for long thought it was possible to find out the char- 

 acter of a combination by means of the reflections, but having 

 only received negative replies to my repeated inquiries from 

 those who ought to know, I have been deterred from investigat- 

 ing the matter for myself until this summer. 



Journ. Q. M. C.j Series II., No. 17. 



