TIM: the first 50 years

26 TIM: THE FIRST 50 YEARS EE December 1986 The speaking clock, British Telecom"s oldest and most popular Guideline re- corded information ser- vice, celebrated its fiftieth birthday this year. Since its start in 1936 it has had three changes of technology, three changes of voice, one change of sex and received more than 10 billion calls. Before the mechanical speaking clock, telephone customers wanting to know the time rang the operator to get "the time by the exchange clock". The true recorded service started with the instal- lation of a pair of clocks in Holborn to serve London customers. The service became nationwide six years later in 1942 with the installation of two more clocks in Liverpool. The first clocks were elec- tro-mechanical devices using photographic storage where the parts of the announcement were recorded on rotating glass discs, recovered by photo- electric cells and as- sembled in the right se- quence to form complete announcements at inter- vals of ten second...