ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



r,29 



arm E serves to impart a rotatory vertical movement to E aliout B 

 th„ ni ^^, combination of the horizontal and the vertical movements 

 the object-carrier G vvonld descrilie a vertical sphere. The object to be 

 examined should be mounted on a pin clamped in the tnbular support <i 



Objective 



Fig. 90. 



the exact postion being determined by rotating the arm into the hori- 

 zontal and then adjusting the pin-depth in the tube, so that the object 

 occupies the centre of the optic field. Bj means of the axis C another 

 rotation has been provided. This axis carries a disk I, on which is fixed 

 the pm-holder. When it is desired to examine separately all the parts 

 of an object of a size superior to the field of the objective, the object- 



