72 BELL SYSTEM TECHNICAL JOURNAL 



About three quarters of this total is accounted for by circuits where 

 the contract calls for 12 hours operation per day, nearly all the re- 

 mainder is accounted for by circuits which remain in vService 24 hours 

 per day. A remaining small fraction is made up of shorter period 

 contracts which are permitted to be as short as 30 minutes per night 

 one night per week, or 10 minutes per day five days a week. 



As an illustration of the extent of use of this service, there are at 

 present 158 full-time special contract circuits between New York and 

 Philadelphia and 89 of such circuits between New York and Boston. 



Foreign Exchange Service 



Closely related to the above is the furnishing of what is called 

 foreign exchange service. This consists of an arrangement whereby 

 a customer in one exchange area is provided with a circuit for his 

 exclusive use to another exchange area, this circuit being associated 

 with a telephone number in a distant exchange so that other telephone 

 stations in that exchange can be connected to the special line without 

 toll charge. By this means, a business office in Boston, for example, 

 can be given a New York telephone number, all New York calls for 

 that number being treated as local calls but being actually completed 

 over the special line to Boston. 



This type of service has a considerable popularity, there being over 

 1,000 such lines in service at the present time. Most of them are 

 for relatively short distances, but some are for material distances, 

 the longest being between Cleveland and New York, a distance of 

 about 900 kilometers. 



Telephone Networks for Program Transmission to Radio Broadcasting 

 Stations 



Radio broadcasting has resulted in the development of networks 

 of telephone circuits for transmitting programs from studios or other 

 places at which they are picked up to the radio station or system of 

 stations from which they are broadcast. By such telephone wire 

 systems the ceremonies of the Presidential Inauguration on March 4, 

 1929, were simultaneously transmitted to 118 radio stations located 

 all over the United States. A statement regarding these interesting 

 telephone networks, the requirements which they must meet and their 

 importance in program broadcasting in the United States is given 

 in a separate paper presented to this Congress (see paper on Wire 

 Systems for National Broadcasting by A. B. Clark). 



