126 



MAGNIFICATION AND MICROMETRY 



[_CH. IV 



the Ocular Micrometer. The table should be filled out by each 

 student. In using it for Micromeiry and Drawing it is necessary to 

 keep clearly in mind the exact conditions under which the determinations 

 were made, and also the ways in which variations in magnification and 

 the variation of the ocular micrometer may be produced ( 177, 178, 

 188, 195- 



FIG. 115 

 MICROMETRY 



180. Micrometry is the determination of the size of objects 

 by the aid of a microscope. 



MICROMETRY WITH THE SIMPLE MICROSCOPE 



181. With a simple microscope (A), the easiest and best 

 way is to use dividers and then with the simple microscope deter- 



