88 



BELL SYSTEM TECHNICAL JOURNAL 



8.000.000 



16.000.000 



14.000.000 



12,000.000 



0,000.000 



8,000.000 



6,000.000 



4.000,000 



2,000,000 



OfVJ^<D<00(\J^<X)<DOCM<J'<OOOOrvj'if(0<00(\J^>000 ^ 

 eOeOoO<0<00><J)0>0)0>00000 — — — — — c\jfVJ<\lf\jf\j 



(Ocoo<o<D<ooOcoaOooo>o>0)0>o>a)o>o>a>o>o>a>a)a>o> 



Fig. 57 — 'Number of telephones in the United States. 



