Place the object on a slide and slip under the 

 clips. 



In this case the low power objective is used 

 for two reasons ; because a general view is sought, 

 involving low magnification and large field with light- 

 giving power and because a higher power cannot be 

 used on account of its short working distance. _The 

 light may and undoubtedly will be found insufficient to 

 distinguish the object clearly. If the instrument is of 

 the American type, swing the mirror-bar upon its axis 



around the stage to a point 

 ,,-.---"** above it so that it will be 



at an angle of about 45 

 ~~~ degrees to its surface. If 



a lamp is used and in the 

 -"* * - same position as when 



used for transmitted light, 

 it is probable that the tube 

 of the instrument will 

 ^ " ' * obstruct the light and it is 



Fig. 48. Illuminating Opaque object then well to move it to- 

 with mirror above the stage. f . 



ward the front. Using the 



concave mirror, adjust so that the light will be con- 

 centrated upon the object, by watching it directly, and 

 then observe through the tube. If it is not sufficiently 

 illuminated continue to adjust the mirror; also vary 

 its distance from the object and swing the mirror bar 

 to a higher or lower point. 



