n.wci\r.i:ia\r, i'roiu.ims or iiii-. ni:i.i. sysium ?2.\ 



of typi'S of .ipp.ir.iliis to lucrl s|H'(ilic infcli.mic.il .md clcclricil 

 ri'(|iiirriiii'iit>. 



What I li.iM- .ilr(.-.ul\ s.iiil iiupli.isl/is llii- iiuportaiur of inniiuirini; 

 work involved in tlu- design of ik-w pi.ml. Wry inli-ri-stinj; iMiniiuvr- 

 ing studifs arc. howcvi-r, also invoKol in roniu-clioii with tlir niaiii; 

 tenanrc of the plant as wt-Il. Tiiis inrUidts tlu- di\ilopinc-nl oi im- 

 proved niaintonanie nu-thods and routines and a eritical analysis ol 

 the results obtaiiutl, judged from the points of view of excellency of the 

 service and econonty of operation. To use a homely illustration: one 

 miRVit have his automobile completeK' gone over by a garage every 

 UK) or 200 miles of running with the result that he woukl probably be 

 reasonably sure of perfect maintenance of the automobile (assuming a 

 perfect garage), but the maintenance costs would be excessively high 

 and out of proportion to the benefit received. On the other hand, 

 however, if no attention is gi\en to the maintenance of the automobile, 

 maintenance costs woukl be at a minimum l)Ut the depreciation would 

 be high, the operation would soon become unsatisfactory and soonei 

 or later the results would be a total interruption to service use. The 

 problem, therefore, evitlently is to find the proper balance litlwtcii 

 o\erall costs and service results, and this is true, of course, ot tlic 

 various engineering problems to be soKed in connection witli tin- 

 maintenance of the telephone plant. 



The engineering work of the Bell System also insolves, to a large 

 extent, relations with other organizations. These relations are very 

 close with other wire-using companies, including small telephone com- 

 panies whose lines connect with those of the Bell System. Important re- 

 lations must be maintained by the engineer with electric power antl 

 electric railway companies, as particularK' important problems of 

 safety and of service arise due to the proximity between their electric 

 circuits and the telephone circuits. These problems involve provision 

 not only for the protection of the plant and employees against the 

 flanger of contact with the wires of other companies but also include 

 coordination of the two systems to prevent excessive inductive effects 

 which often become important where electric power lines or electric rail- 

 ways and telephone lines run parallel to each other. The electric com- 

 panies and the telephone companies often find it advantageous to enter 

 into arrangements for the joint use of pole lines and this presents 

 many problems requiring consideration by the engineer. It is evident, 

 therefore, that the problems of the telephone engineer cover a very 

 wide and interesting field in mechanical, electrical and other arts. 

 both within the business itself and in relation with other uiihtics .iiui 

 municipal, state or national bodies or associ.itions. 



