ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



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impact on the front-silvered adjustable mirror S l5 are projected on to 

 the screen. Sharpness of projection is attained by manipulation of the 

 handwheel E, x governing the objective. The magnification attained is 

 8 to 10-fold, and the images are 3' 2-4*0 m. in diameter. A second 

 objective of shorter focus is provided for the purpose of bringing out 



Fig. 55. 



peculiarities of the larger pictures. This second objective 2 , fitted 

 with a similar mirror S 2 , is pushed into position in the direction ot tne 

 arrow, and O l is thereby automatically put out of action. b 2 is so 

 mounted that it forms its image in the same spot as Si does. f is a 

 smoked-glass plate for convenient observation of the object on tne 



April 21st, 1909 s 



