TELEPHONE SYSTEM OF THE UNITED STATES 



89 



z 

 o 



CL 



o 



CL 



o 

 o 



oc 

 u 



Q. 



Ul 

 U 



z 

 o 



r 



Q. 



U 



_l 



u 



I- 



Jjnujry lit o^ eich yeir 



Fig. 58 — Telephone development in the United States. 



