LM Ericsson Model N1168 Railway Wall Telephone

Telephone has Copper trim and porcelain with unique bell shape
All Copper should be japanned black - factory blueprints and info are below

	Original Blueprint for N1168 - click for larger view blueprint shows Southern Railway as customer in 1932 Thanks to Bob Freshwater - Bobs Telephone File

information from Andrew Emmerson author of "Old Telephones"

The railway telephone, type N1168, was produced exclusively for the Southern Railway, one of the four big railway companies before nationalization in 1948. These telephones were used extensively on long 'omnibus' (all-purpose) code-ringing circuits. As you may have noticed, the bell relay is polarized to respond only to positive currents; the switchboard at the parent exchange responded only to negative currents (or vice versa). This discriminating system mean that signal cabins didn't answer calls intended for the exchange and vice versa.