Rack_mounted_telephone_equipment_(1923).png
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Summary
Description Rack mounted telephone equipment (1923).png |
English:
Diagram of
w:replay racks
with telephone equipment mount on vertical rails. This system was standardized for use in Bell System central offices in 1922-23.
Original caption: "Fig. 28 — General View Showing Typical Group of Equipment Units Employing Panel Mounting Method"
|
Date | |
Source |
Demarest, Charles S. (July 1923). "Telephone Equipment for Long Cable Circuits". Bell System Technical Journal. Vol. 2 no. 3. New York: American Telephone and Telegraph Company. p. 138. [1] |
Author | Charles S. Demarest |
Licensing
Public domain Public domain false false |
This work is in the
public domain
in the
United States
because it was
published
(or registered with the
U.S. Copyright Office
) before January 1, 1929.
Public domain works must be out of copyright in both the United States and in the source country of the work in order to be hosted on the Commons. If the work is not a U.S. work, the file
must
have an additional
copyright tag
indicating the copyright status in the source country.
Note: This tag should not be used for sound recordings. PD-1923 Public domain in the United States //commons.wikimedia.org/wiki/File:Rack_mounted_telephone_equipment_(1923).png |