PROF, bailey’s indicator STAGE. 
33 
Fig. 12. 
CHEVALIER’S PRISMATIC BODY, AND BAILEY’S INDICATOR STAGE. 
62. Prof. Bailey’s Indicator Stage, shown also in Fig. 12, 
as attached to microscope No. 5, has a graduated movement in 
two directions, by turning the milled heads seen under the stage. 
These milled heads are attached to two pinions, one revolving 
within the other, and they move the stage in two directions re- 
spectively at right angles to each other. On each border of 
the stage are scales graduated to of an inch, which serve to 
determine the exact position of the stage when an object is in 
the centre of the field. If a slide is placed in a certain fixed 
position on this stage, the exact position of any object seen in 
CATALOGUE OF ACHROMATIC MICROSCOPES. 
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