. Bell telephone magazine . Grace Cable Terminal: 1903. Operating Exhibit Dem-onstrating Permeability. Figure 9. Unit of Call Announcer Apparatus: 1929. Figure 10 the bell system historical museum Central Office Apparatus The development of central office apparatus occupies thegreater part of two single cases. In these are shown exhibitsof the earliest and latest plugs, jacks, keys, signals, relays,lamps, lamp caps, cord weights, resistances, message registers,and switchboard clocks. The plugs and jacks begin with codenumber 1 in each case and continue by type to the latest stand-ard designs.
. Bell telephone magazine . Grace Cable Terminal: 1903. Operating Exhibit Dem-onstrating Permeability. Figure 9. Unit of Call Announcer Apparatus: 1929. Figure 10 the bell system historical museum Central Office Apparatus The development of central office apparatus occupies thegreater part of two single cases. In these are shown exhibitsof the earliest and latest plugs, jacks, keys, signals, relays,lamps, lamp caps, cord weights, resistances, message registers,and switchboard clocks. The plugs and jacks begin with codenumber 1 in each case and continue by type to the latest stand-ard designs. Prior to the present use of code numbers, partsof central office apparatus, like subscriber sets, were known bythe name of the designer or the locality where first used. Forexamples, we have the Williams, Gilliland, Chicago, Detroit,Philadelphia, Liverpool, Antwerp plugs and Scribner, Thayer,Philadelphia, Central Avenue Union, Detroit jacks, a Mc-Daniels switch and others. Most of these however, were laterassigned code numbers. Signals and relays begin with exhibitsprior to the time code numbers were assign
Size: 1868px × 1337px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthoramerican, bookcentury1900, bookdecade1920, bookyear1922
