Apparatus for measuring 
and counting mieroseopieal objects. 
A. Measuring Apparatus. 
With regard to measurement of the thickness of micro- 
scopical objects see p. 29. 
The folloAving instruments are intended for measuring the 
length and breadth of microscoincal objects. 
Stage Micrometer. 
a) One millimeter divided into 100 parts ; mounted on a glass 
slip, in case 
b) Ten millimeters, the last being divided in tenths . . . 
These serve merely as standards of known value 
for determining the micrometer value of the meas- 
uring instruments proper. 
Other divisions on application. 
Vide also Nos. 36—38. 
¥ig. 30. 
Eye-piece Micrometer. 
Eye-piece Micrometer. Arbitrary divisions on a glass disc 
to drop into the eye-piece ; for measuring the magnified image of 
