LABORATORY AND TEACHING METHODS 



585 



Table or Micrometer Values. — {Continued) 



Step Micrometer 



The special features of the step micrometer (Stufenmicrometer) are that ten 

 intervals constitute one group. Each group is marked partly in white and partly 

 in black. The black groups are accompanied by a white and the white groups by 

 a black figure. These two different markings facilitate considerably the measure- 

 ments of specimens of the opposite color. The grouping of ten intervals to one 

 distinct group allows a rapid and convenient count. The value of one interval of 

 the step micrometer is 0.06 mm. 



Directions (Fig. 208). — Object micrometer i mm. divided into 100 parts to be 



