USING THE MICROSCOPE 
313 
is simply pulled out until the length is 160 mm. (Fig. 116). Where 
a nosepiece is used, its height should be measured, and the draw-tube 
Body Tube — _ 
Nosepiece .—f - 
Objectives:- 
OcULRR. 
Drbw-Tube 
Graduated ^>hort 
Slide.. 
"Revolvi 
Strg,e-t 
Adjustable^.,,, 
SPRING FlNC,ER. 
Condense* Mou 
Lowe* IrisTi 
for Oblique Lic^ht 
5tace Centering, 
„ Sotiws. 
IRROR,- 
Mirror Forn- 
Mirror Bar..- 
P A c *- & Tin ion 
Button for 
Substf\ce. 
-$ Pinion 
Course Adjustment. 
Fine A^ JUSTMENT 
Buttons 
-Concentric 
Rd justin ^Buttons. 
Lonq 
Slide- 
-Arm 
— Inclination 
Joint 
Pillar. 
— Horseshoe 
3ase. 
Fig. 115.—A modern microscope 
should be pushed in a distance equal to the length of the nosepiece. 
There are in general use two practical methods of measuring micro¬ 
scopic objects, one by means of the ocular micrometer, and the other 
by means of camera lucida sketches. 
