FIG. 9. SECTION or A MICROSCOPE 



01, object ; 02, real image in F2, transposed by the collective lens, to Os, real 

 image in eyepiece diaphragm; 04, virtual image formed at the projection dis- 

 tance C, 250 mm. from EP, eye point ; CD, condenser diaphragm ; L, mechan- 

 ical tube length (160 mm.) ; 1, 2, 3, three pencils of parallel light coming from 

 different points of a distant illuminant, for instance, a white cloud, which il- 

 luminate three different points of the object. (After Bausch & Lomb Optical Co.) 



38 



