1905.] 



on High Power Microscopy. 



!l 



of the microscope. Microscopists call Yv^. 7 a "rotten image." 

 Fortunately they have not l)een called upon to find a description for 



Fig. 8. 



A is the principal microscope. 



B is the auxiliary microscope which replaces the eye-piece of the principal 



instrument. 

 C is the image plane of the principal microscope, and indicates the position 



in which the oscillating screen is mounted. 

 D is the tripod supporting the screen and its motor. 

 rf is a focusing ring by which the screen supporting arm is adjusted to 



the correct level. 

 E is the screen supporting arm, and 

 e is its elbow joint. 



F is a ring for coarse focusing of the auxiliary microscope. 

 M is an electric motor driving the oscillating screen. 



Fig. 9, for the vice of that image, formidable as it looks, is very 

 easily corrected. The grain of the glass is conspicuous only so long 



