Fia-. 14. 



if Nat-bet's microscope, to enable two observers to examine an 

 object at the same time 



Fig. IS. 



Nachet's binocular microscope, p. 11. 

 See also Fig. 45. Plate X. 



Fig. 16. 



Prisms in Powell So Lealand's binocular 



arrangement for 



highest powers. 



AA. rays of light pr ceeding from otrjecb 

 glass. B, parallel p ece of glass. C, tri- 



angular prism. 



DDDD, emergent rays, 

 p. 11. 



Fig. 19. 



The arrangement of the prisms and 

 lenses in Tolles's binocular eye- 

 piece, made by Ladd. p. 12. 



a 



Binocular microscope as recently 



arranged by Mr. Wenham. and 



now generally adopted, p. 11. 



Mirror. 



(To face page 12. 



