ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



761 



This movement has not only measuring capabilities, but also acts as a fine- 

 adjustment to the mechanical stage, and this, when objectives with high 

 magnification are used, is of great value. The quick movements by 

 rack-and-pinion cover a range of 3 in. by 1 in. The stage-screws have 

 threads ^ mm., and the drum has 100 equal divisions, thus permitting 

 measurements up to ^^ mm., or TB V<y m - 



Ross' No. 2 "Standard" Metallurgical Microscope.* — The ad- 

 justments and construction of this stand (fig. 160) are on the same 



Fig. 160. 



lines as those of the Ross' No. 2 Standard, but the instrument is 

 specially adapted for metallurgical work. One revolution of the milled 



* Ross' Catalogue, 1908, pp. 10-11 (1 fig.). 



Dec. 16th, 1908 



3 E 



