OPERATION 



141 



nearby stations should have signals composed of " shorts." The assumption, of course, 

 is that most of the calls originate at one end of the line as, for instance, at a super- 

 visor's headquarters. 



For the "ring off" signal, one short ring will be found most satisfactory. 



For the main headquarters, one long ring is generally preferred. 



2 LIST OF BELL CALLS 



The total number of possible signals made up of not more than four rings is 

 thirty. If five rings are used, a total of sixty-two signals may be employed but thirty 

 generally suffice. These thirty signals are shown below : 



1 One short 



2 One long 



3 Two short 



4 Two long 



5' One short, one long 



6 One long, one short 



7 Three short 



8 Two short, one long 



9 One short, one long, one short 



10 One short, two long 



11 One long, two short 



12 One long, one short, one long 



13 Two long, one short 



14 Three long 



15 Two long, two short 



If)' One long, one short, one long, one 

 short 



17 One long, two short, one long 



18 One long, one short, two long 



19 Two long ? one short, one long 



20 Three long, one short 



21 Four long 



22 One long, three short 



23 One short, three long 



24 One short, two long, one short 



25 One short, one long, one short, one 



long 



26 Two short, two long 



27 One short, one long, two short 



28 Two short, one long, one short 



29 Three short, one long 



30 Four short 



3 ASSIGNMENT OF CALLS TO OCCUPIED 'STATIONS 



The first fourteen of these signals consisting of only three elements or less should 

 be assigned to the busier and more important stations. The ones consisting largely 

 of short rings and especially those beginning with a short ring, should be given to the 

 nearby stations. The remaining sixteen rings consisting of four elements each are 

 arranged approximately in the order in which they will transmit best over long lines in 

 poor condition. Of course, nearby stations may be given a signal from near the end 

 of this list, either when they have little business or when they have considerable 

 business but there are no short calls available. 



4 ASSIGNMENT OF CALLS TO UNOCCUPIED STATIONS 



A number of stations will often be located on forest lines where it is not antici- 

 pated that any calls will be put in. The lookout telephone sets, for instance, mounted 

 on posts are usually cut off from the line by a switch and only used for calling other 

 stations. Such telephones, however, should be assigned a four-element, or if necessary 

 a five-element, call, so that if at any time they are used for an extended period the 

 various posted lists of calls will show the station signal. It is also advisable to 

 reserve two or three of the better-transmitting three-element or four-element calls for 

 the use of emergency stations. 



