i8 



OBJECTIVES FOR THE MICROSCOPE 



[Ch. I 



Mirror The plane and concave mirror 

 object to the microscope and to the eye. 



Object The object to be seen. 



/ The principal focus of the 



Objective The lens serving to 

 ject. 



Axis The principal optic axis 

 eye. 



r im The real image formed 

 above the principal focus 



Ocular The convex lens 

 real image. 



cr The cornea of the 



rs The refracting sur- 



L The crystalline lens 



ri The retinal image; 

 with the real image formed 

 as compared with the 



Virtual Image The 

 jected into the field of 

 250 millimeters. 



This image is in- 

 with the object, but 

 the real image formed 

 The microscope enables 

 small object as if it 

 the size of the vir- 

 placed at a distance 

 from the eye. 



to reflect the light up through the 



objective. 



form a real image of the ob- 



of the microscope and cf the 



by the objective; it is just 

 rs of the ocular. 



aiding the eye to see the 



eye. 



face of the schematic eye. 



of the eye. 



it is inverted as compared 



by the objective, but erect 

 object. 



retinal image pro- 

 vision at a distance of 



verted as compared 



i\\ erect as comparedwith 



by the objective (r i m). 



v \i the eye to look at the 



ft were enlarged to 



\ tual image and 



\\ of 2 50 millimeters 



Virtual 

 Fig. 20. Compound Microscope with Projected Virtual Image. 



