Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems (1921)
Smith, Arthur Bessey, b. 1875, Campbell, Wilson Lee · New York : McGraw-Hill · leaf 277
tem is lessexpensive than the automanual to install, but which is the more econom-ical to operate and maintain in single-office systems remains to bedetermined. The automanual is adapted to multi-office systems where considerableinter-office trunking is done, because the operators work is the same… … 3OT3 Connector StfS. 4 Party Link Key Set —o°°°o Switches\,°°° o | Opera torsi| —I Key Sets* —|
Telephone
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
