Postmaster General presents first school telephone set at Eltham - 160 to be equipped . Sir Kingsley Wood , the Postmaster General , presented the first Post Office school telephone set to the headmaster of Eltham Central School , Well Hall , Eltham . Altogether 160 of these sets , which are used for demonstration purposes , will be distributed to various schools . Photo shows ; Sir Kingsley Wood watching two pupils operate the new telephone apparatus at the Eltham Central School . 7 December 1933