r.xGixur.mxG i-rohi.f.ms or hie nii.i. sYsriiM s.m 



rut ling in additional loading: roils as rf(|iiirfd. V'm. 10 gives an 

 intiTi'sting \ii'\v of tlu- i\d)!r n\vr ihv Alk-glu'nii's, showing us again 

 tlu- ini'cit.inical prolilcins invoKi'd in design and conslruction. In 

 this ease the fai>le follows c!ose!>' tiie open wire line, which in time will 

 he disnianlled. 



It may be of interest in this connection to state th.it the |)lans to he 

 compariil in the study of toll cahle projects generally differ primarily 

 in the dates at which they contemplate supplementing or replacing 

 open wire service by cable. Conditions under which cable becomes 

 economical depends, of course, on many factors. Perhaps the most 

 iinport.uU single factor is the rate of growth of the circuit requirements. 

 The tletailed design of the cable also involves very interesting studies 

 of the economical number of circuits to provide in the cable sheath, 

 .Also the economical gauge of each circuit must be considered, com- 

 paring in many cases the economies of a larger gauge with those of a 

 smaller gauge provided with a greater number of telephone repeaters. 



The design of the toll cable as discussed is but one illustration of the 

 design of the toll plant extension as a whole, a problem which, in 

 general, involves the consideration of the relative desirability of 

 additions to existing open wire toll lines, building new open wire toll 

 lines, applying carrier telephone s\'stems to existing lines or installing 

 toll cable. 



Ti:i,i£PHONK Probli:m in Xi w York City 



As another specific illustration of the tek'i)h()ne engineering problem, 

 I will describe briefly the matter of adetiuateh- meeting ref|uirements 

 in a large city, using for purposes of illustration the situation in New- 

 York City and the metropolitan area. This [larticular situation doubt- 

 less presents one of the most difficult engineering problems and in 

 some respects is unusual, yet, on the other hand, it fairly represents 

 the kind of engineering problem with which the Hell -System engineers 

 nuist deal at all times. 



Fig. 11 indicates clearly the magnitude of the [)resenl du^\ future 

 problem in the .\ew York metropolitan area, as viewed from the 

 number of telephones. In 1(I0."> there were 220,000 stations in New 

 York Cit\- and 300, ()()() stations in the metropolitan area. By 192.") 

 the figures had increased to 1,400,000 for New York City and 1,000,000 

 for the entire area. By 1945 it is estimated there will be over 3,000,000 

 stations in New York City and over 4,000,000 in the metropolitan area. 

 Part of this growth can be ascribed to the normal increase in the 

 popiil.itiot) and p.irt. of course, to the tendency to make more use of 



