igS 



CLASS DEMONSTRA TIONS 



[C//. Ill 



Fig. 155. Compound Microscope with triple nose-piece and objectives and 

 ocular in position. The nut; below the condenser is drawn to one side. This 

 ring is for blue glass or for a central-stop to use in dark-ground illumination 

 Ci /".)')• In demonstrations it is a great advantage to have a fine hair in the 

 ocular as shown in Figs. 153-154. (Cut loaned by Williams, Brown & Earle, 

 /'hi I a.) 



