Oral Answers to Questions — Coal Mining Industry. – in the House of Commons am ar 7 Rhagfyr 1926.
asked the Postmaster-General what action has been taken by his Department with a view to apprising telephone subscribers of unanswered calls?
The Postmaster-General is considering the advisability of introducing this system.
Has an experimental test already been made at the central exchange, and with what result?
A working test has not been made. It would have to be carried out before the system was introduced.