ZOOLOGY AND BOTANY, MICliOSCOPY, ETC. 



691 



total length of the tube is 16 cm. open, 10 ■ 3 cm. closed. The pecu- 

 liarity of the stand is the absence of ;i pillar between the foot and the 

 hinge for oblique position (fig. 75). The mirror works in a clamping- 

 ring between the toes of the horse-shoe foot ; it can be shifted forwards 

 and backwards. "When the stand is inclined at about 30° the distance 



Fig. 75. 



between the mirror centre and the diaphragm centre is about 4 cm., and 

 the sliding adjustability of the mirror renders it possible to bring the 

 mirror centre into the optical axis. As will be noticed from the illus- 

 trations, there is only one adjustment, a rack-and-pinion. But in all 

 modern instruments the rack-and-pinion is so well made that it suffices 

 for this Microscope. 



