File:Bell telephone magazine (1922) (14753922824).jpg

Identifier: belltelephonevol21mag00amerrich (find matches)
Title: Bell telephone magazine
Year: 1922 (1920s)
Authors: American Telephone and Telegraph Company American Telephone and Telegraph Company. Information Dept
Subjects: Telephone
Publisher: (New York, American Telephone and Telegraph Co., etc.)
Contributing Library: Prelinger Library
Digitizing Sponsor: Internet Archive

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must be under-stood, takes place many times in rapidsuccession as one observation postafter another reports—since the speedof planes is great and observers arelocated only a few miles apart. Ittakes but a moment for the markerson the map to make a definite line.Also, reports of a flight from succes-sive observation posts corroborateeach other, and thus of themselvesrule out an occasional discrepancy onany one report. 1 HE markers, having so swiftly be-come a line, are now as swiftly evalu-ated by a filterer, who places on asmall stand nearby cards describingthe observed flight, and replaces themarkers with arrows indicating direc-tion. To show the speed of the flight,the color of the arrows is alternatedat regularly timed intervals. FLASH MESSAGE FORM Call your telephone central and say: ARMY FLASH Central will connect you with an Army Information Center. When you hear: ARMY. GO AHEAD PLEASE, you say: FLASH and continue message you have checked on form below, in the order indicated:
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Observers Report FormInformalion about aircraft seen or heard is telephoned in this order to plotters at the designated filter centers 10 Bell Telephone Magazine FEBRUARY The information about each air-plane flight in a filter area, havingbeen thus evaluated or filtered, isnow ready to be transmitted instantly-over private telephone lines to anArmy information center. Ihe heart of the aircraft warningsystem is the information center. Itis here that decisions are made, actionis initiated. Here is the operations board for theparticular defense region. Like the filter board, but larger, it includes allthe filter areas of the region. Here,too, plotters place their symbols; butnow they are duplicates of the evalu-ated information received moment bymoment from tellers at each filterboard in the region. In the same room are the seawardboard, on which all flights approach-ing from the sea are plotted; and thestatus board, on which are shown theavailability, position, and condition ofpursuit s

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