ZOOLOaT AND BOTANY, MICROSCOPY, ETC. 



419 



vice versa, on the pivot (i. e. like a pendulum, whence the name). It 

 is then shifted slightly by the screw on the right, and the pendulum 



Fig. 68. 



movement repeated, and so on until the whole of the object has passed 

 under observation. 



2 E 2 



