MICROMETRY — MICROMETRIC MICROSCOPES 
177 
moved Independently by means of the micrometer screw M^, 
thus permitting a very exact adjustment of a point or line under 
the cross-hairs of the microscope B. At the opposite end of the 
Fig. 112. Zeiss Traversing Microscope or Comparator. 
stage a second micrometer screw displaces the entire stage. 
The section s‘^ carries a finely graduated scale whose rulings 
are read by the reading microscope A of fixed focus. Each 
microscope is provided with a fixed ocular with cross-hairs mov- 
