File:Baltimore and Ohio employees magazine (1912) (14758525371).jpg

Identifier: baltimoreohioemp06balt (find matches)
Title: Baltimore and Ohio employees magazine
Year: 1912 (1910s)
Authors: Baltimore and Ohio employees magazine Baltimore and Ohio Railroad Company
Subjects: Baltimore and Ohio Railroad Company
Publisher: (Baltimore, Baltimore and Ohio Railroad)
Contributing Library: University of Maryland, College Park
Digitizing Sponsor: LYRASIS Members and Sloan Foundation

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
ng inextricablytangled when all are waltzing togetherdown the common path. This seems beyond behef, but it isexactly; wh^t is occurring right now.Mr. Jones in his office at Pittsburgh cantalk business to Mr. Smith in his office inWashington over the same fine that hiswife in her Pittsburgh home uses in dis-cussing domestic problems with Mrs.Smith, who is at her residence in Wash-ington. At the same time and over thesame line three other paifs of conversa-tions are occurring and -perhaps twotelegraph circuits are established andnone of them interferes with any other. How is this possible? The moderntelephone is reasonably familiar to every-one. It is known that it has long beenpossible to take two adjacent metalHctelephone circuits and so arrange them asto provide for an additional or phantomcircuit. Coincident with this phantomit is also known that each of the four wirescan be employed for an ordinary tele-graph circuit without interfering withits employment as a part of the telephone
Text Appearing After Image:
THE BALTIMORE AND OHIO EMPLOYES MAGAZINE 23 highway. It is known also that when aperson talks into a telephone transmitterhe generates feeble electric currents whichhave very curious and complex forms andwhich involve a wide range of frequen-cies—extending up to 2,000 alternationsper second. In a word, it is known thatif the telephone transmitter, receiver andHne are good, each part of the circuit willhave a current which pictures a faithfulreproduction of the disturbances whichthe voice produces in the air. It is known also that if our circuit is tobe satisfactory it must, so far as the re-ceiver at least is concerned, be free fromelectric currents of voice frequency saveonly those produced in the transmitterused by the one to whom we are talking. If this is so and if all human voices em-ploy about the same range of frequencieshow is it possible to use a single pair ofwires for many simultaneous messagesand have each message go only to theterminal designed? It was this difficultywh

Note About Images