48 



rUNCTlONS OF LIVING THINGS 



2. NOTE. — The stand consists of the following parts: base (A), pillar (B), 

 stage (M), arm (C), tube (D), diaphragm (S), mirror (0), revolving nose piece (E), 

 the coarse (K) and the fine (L) adjustment. 



-XSl' 



!LS' 



Of what material is the stand made? What are the advantages of using such 

 material ? 



3. Note. ■ — The stand rests upon a broad base or foot. 



What is the sfiape of the base? Why should the base be broad and 

 heavy? 



