THE MICROSCOPE IN SECTION 



r. Huygenian ocular (see p. 102 for positive 

 ocular). 



2. Draw-tube by which the tube is length- 

 ened or shortened. 



3. Main tube or body containing the draw- 



tube, and attached to the pillar by the 

 arm 



4. Society screw in the lower end of the 



draw-tube. 



5. Society screw in the lower end of the 



tube, 

 (1 ( >bjective in position. 



7. Stage, under which is the substage with 



the substage condenser. 



8. Spring clip for holding the specimen. 



9. Screw for centering, and handle for the 

 iris diaphragm in the achromatic con- 

 denser (see Fig. 41 ). 

 10 Iris diaphragm outside the principal 

 focus of the condenser for use in cen- 

 tering (§81) 

 Mirror with plane aud concave faces. 

 Horse-shoe base. 



Rack and pinion for the substage cou- 

 denser 

 i,|. Jointed pillar. 



is. Part of pillar with spiral spring of fine 

 adjustment. 



Screw of line adjustment. 



Milled head of coarse adjustment. 



