CH. IX] 



THE PROJECTION MICROSCOPE 



223 



Micro-projection is simply a refinement of ordinary magic 

 lantern projection. If one understands the principles, and has 

 mechanical skill to apply them, there is no great difficulty in micro- 

 projection. But if ordinary magic lantern projection is unsatisfac- 

 tory 7 in untrained hands, micro-projection in such hands is in- 

 tolerable. 



This is, however, such a powerful aid to the teacher and the 

 lecturer that the time necessary to learn to use it properly is not to 

 be counted. With micro-projection the beauties of structure and 



Condenser 



H C 



FIG. 122. MAGIC LANTERN FOR COMPARISON WITH THE PROJECTION 

 MICROSCOPE (See fig. 2). 



form are made visible to an entire audience with all their color, 

 delicacy and exquisite perfection. 



Furthermore, the teacher or lecturer can indicate on the screen 

 the special points to be noted, and feel confident that his auditors 

 see the special features and do not get confused by the mass of 

 details, as when looking into a microscope. Often too, the most 

 interesting and important structures in a specimen are not so 

 striking as some less important detail, and the important points are 

 likely to be missed unless pointed out. 



353. Limitation of the Projection Microscope. Perfect and 

 useful as the projection microscope is, it is limited in its powers. 

 One can show with full satisfaction to a large audience (200 to 

 1000) only those details which an experienced observer can see by 



