Show USING TELEPHONES 01 1 TO DISPATCH TRAINS The Tho Cummin Cummings s l Wray calling apparatus atus for use on train dispatchers' dispatchers telephone tele teo phone lines is in service on the tire two busiest bus bus- iest jest divisions di of the Chica Chicago o Milwaukee kee keo St. St Paul Pauli on two divisions of the Delaware Lackawanna Western and andon andou on ou one or more or-more t more divisions of tho Ch Chicago cao Burlington Quincy tho the Atchison To- To peka Santa Fe tho the Great Northern the 1 Michigan chi an Central the tho Chicago o Northwestern the Louisville Nashville Nash rifle ville lle and tho the Rock flock Island Pacific Tho The apparatus is mado made both by tho Western Electric company compan Chicago Chi Chii cago and tho the Kellogg Switch Supply company Chicago The essential element in this calling system consists of or synchronous clocks one ono at the oO office cc and oneat ono one at each station The first operation on performed by bv tho the dispatcher when he wishes to call a n. station is to close n a circuit cir cir cir- which starts all tho the clock chock movements move mo meats ments in iii tho the system all having been held heIr at zero by a detent which is released released re re- re- re 13 leased rl b by ba a rela relay The second hand of each cach clock dock sweeps over o a series of contacts closing erich each successively oly and each of oC tho the twenty eight ht or more contacts con can tacta tach is assi assigned ned to ono of twenty eight stations lor br or example if jf station No 10 is the thc one to be ho called 1100 tho the dispatcher presses 8 a ke key ke- which thich causes caules a current to tobe tobe be 10 sent Pent to the thc line when tho second baud band of his clock chock passes over its tenth con can tact At station No 10 the thc clock contact contact con cou tact for the local apparatus at nt that station station sta sta- tion is closed at tho the same moment by the tho local clock and aDd the calling relay rela at that station f being thus switched into the thc main line lino closes its points energizing 1101 n. n local 10 circuit which rings rings a bell This relay being a 3 4 stick stick J relay holds tho the hell bell circuit closed l until the time operator heeds tire the bell and opens the bell cir cir- cir cir- |