Mechanical tube 

 ength (160 mm) 



Projection distance 

 (250 mm) 



Entering 



pencils 



2 of 



parallel 



light 



Fig. VIII-1. Section through the optical axis of a standard laboratory-type 

 microscope, showing construction of objectives, eyepiece, and condenser. Since 

 the condenser is in place note how the plane mirror is used in connection with the 

 condenser diaphragm to illuminate the object. 1, eyepiece. 2, tube. 3, coarse 

 focusing adjustment. 4, fine adjustment. 5, curved arm. 6, base. 7, substage. 

 8, mirror. 9, condenser. 10, stage. 11, objective. 12, nosepiece. By courtesy 

 of Bausch and Lomb Optical Company, Rochester, New York. 



313 



