There are also 1700 teletypewriter units equipped for both sending and receiving in Metropolitan Chicago. ... In manual offices the chief operator will busy out defective trunks and report them to the wire chief. ... They maintain five central stations equipped to receive and dispatch fire alarm, burglar alarm, and other emergency calls that might be transmitted to them from any of their approximately 6, 000anbsp;...
|Author||:||Chicago (Ill.). Civil Defense Committee|