The GPO used this strange wall telephone, in rural areas, between 1896 and 1900.  It's intension was to prevent bystanders from over hearing the conversation.

It was called the Horse Collar because it resembled a collar used by cart horses.

The transmitter, a Deckert type, was fitted in a wooden box with an elliptical cushion in which the caller placed their head.  The cushion was made to be flexible and to make an airtight seal around the callers face.  Early models used a cushion of leather stuffed with horse hair.  Later models used a pneumatic rubber tube.

Because of the airtight seal the manufacturer fitted a special ventilator which used glass baffles to stop speech being heard.

This insanitary design was highly unpopular and the phone lasted 4 years before being removed form the GPO portfolio.

See also History of BPO Telephones

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Last revised: November 08, 2023