Image: Bell telephone magazine (1922) (14569847558)

Description: Identifier: belltelephonemag09amerrich (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 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: fall back, and then closed the circuit through heavycalling battery B-l, operating tap bell R-D. The operatorthen shifted plug P-d from the right-hand to the left-hand hole,disconnecting subscriber Z)s central office burglar alarm circuitand connecting the operators telephone, T, to subscriber Z)sline. When his bell rang, subscriber D moved his substationswitch from the right-hand to the left-hand contact, thus dis-connecting his substation burglar alarm circuit from his lineand connecting in his telephone, T-D. The operator, after notifying subscriber D that subscriber Bwished to talk with him, removed plug P-d from the left-handhole, moved switch 5 to its right-hand contact, and insertedplug Q, at the end of cord C, in hole H-d. This placed thetelephones of subscriber B, the operator and subscriber D all inone circuit (Fig. 4). The operator could thus determine, bylistening in, when the conversation was finished. When thisoccurred, the operator withdrew plug Q from hole H-d, re- 209 Text Appearing After Image: 210 THE FIRST TELEPHONE SWITCHBOARD placed plugs P-b and P-d in the right-hand holes of the centraloffice plug and block switches, and moved switch 5 to its left-hand contact. When subscribers B and D had moved theirsubstation switches to the right-hand contacts, the operatorrestored the shutters of annunciators A-b and A-d (the latterhaving fallen when its galvanometer circuit was opened), andclosed switch W. The apparatus at the central office and sub-stations was then in readiness for another call to be made. G. K. Thompson,R. B. Hill. Note: The authors wish to express their indebtedness to Mr.W. L. Richards, Consulting Historian of the Bell TelephoneLaboratories, for his assistance in the preparation of this arti-cle. 211 Worlds Telephone Statistics January 1, 1929 ACCORDING to the latest annual survey of the worldstelephones which was recently completed by the ChiefStatisticians Division of the American Telephone and Tele-graph Company, there were 32,712,284 telephones in the wor Note About Images Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.
Title: Bell telephone magazine (1922) (14569847558)
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