THE COMPOUND MICROSCOPE. xi 
lenses and tube. The mirror should be turned at 
an angle of about 45° toward the window from 
which the best light comes. Obtain the best 
diffused light. Do not get the image of the 
source of light (e.g. the sun) in the mirror, and 
do not take reflected light (e.g. that reflected by 
a wall). 
2. Focus. 
Place on the stage the temporary or permanent 
preparation (the 3 in. x 1 in. glass slide, in the 
center of which is mounted the small object in 
some fluid medium, and covered by a thin “cover 
glass”). If the stage is to be inclined by means 
of the hinge in the column, the slide should be 
firmly held by the “clips” situated near the edge 
of the stage. Slowly lower the tube by the “coarse 
adjustment ” until it is very close to the specimen, 
then look through the lenses and raise the tube 
until the object comes into view. Then with the 
“fine adjustment” slightly raise or lower the tube 
until the object is distinct ; at the same time ad- 
just the slide with the other hand. Use low 
power (l.p.) and then the high power (h.p.). 
Why? Sketch the object and compare your 
sketch with the position, direction, and size of 
the specimen on the slide. What are your obser- 
vations? Does a hand lens (simple microscope) 
have the same effect? Why? Read carefully 
notes 1 and 2. 
SUMMARY. 
1. Place the lenses in position. 
2. Adjust the preparation on the stage. 
