|Automatic Wall Telephone
These instruments are very similar in design to our magneto mining types, but are equipped with dials for working to an automatic exchange.
They have been specially designed for outdoor use and will be found to be particularly suitable for railway and shipyards, docks, mines surface systems, factories and other places where they will be exposed to atmospheric and other conditions detrimental to the ordinary type of instrument.
The dial mechanism is mounted on the inside of the inner door and is operate through a gland by the finger plate which is fitted in the recess of an annular casting, thus protecting it from damage.
The cast iron case is water-tight, and the inner door is fastened by screw locks requiring a special key for opening. The outer door effectually protects the speaking equipment and dial when not in use.
The apparatus coils and wiring are specially treated to prevent the detrimental effects of moisture and gases.
Overall dimensions 19.25 x 12.5 x 10 inches.
Taken from the Ericsson Telephone Catalogue, edition No. 26, supplement 1932
Last revised: October 02, 2019