140 



REl.L SYSTEM TECHNICAL JOURNAL 



I-"in. 1. A hirllKT illiistiatiiin of low-power iiholoniicidKra|iliy in llu- 

 study of telephone parts: 



(a) Intermediate pinion of calHni; dial. Diameter of i>ivol .050 inch. 

 .Maunifieation, 14 X. 



(b) The eflfect of laboratory wear tests on small shafts. Magnification, 4 X. 



