Using the Microscope 



281 



15 mm. to reach the length of 160 mm., even when the nosepiece is 

 in place. Where there is no revolving nosepiece, the draw-tube 

 is simply pulled out until the length is 160mm. (Fig. 103). Where 



PINION 

 f COARSE ADJUSTMENT. 



FINE ADJUSTMENT 

 BUTTONS 



OBJECTIVES --- 



SHORT 



DEVOLVING 

 STAGE 



ADJUSTABLE 



SPRING FINGER 



CONDENSER MOUNTING N 

 DROP SWING 



LOWER IRIS DIAPHRAGM-' 

 FOR OBLIQUE LIGHT. 



CENTERING 



M I R R R r - 



MIRROR 



MIRROR BAR.- 



Tfocn & PINION 

 BUTTON. 



CONCENTRIC ADJUST 

 ,-ING BUTTONS 



GRADUATED LONG 



INCLINATION JOINT. 



HORSESHOE 



FIG. 102. A modern microscope 



a nosepiece is used, its height should be measured, and the draw-tube 

 should be pushed in a distance equal to the length of the nosepiece. 

 There are in general use two practical methods of measuring micro- 

 scopic objects, one by means of the ocular micrometer, and the other 

 by means of camera lucida sketches. 



