What we did - making a telephone from tin cans

The story below is not the exact same way we used to make ourselves a telephone when we were young. We did not use anything other than the empty tin cans and a bit of string. Otherwise the principle was the same - just keep the string from becoming slack. It really did work, even over many yards (metres).

How to make a telephone
(Source "The fabulous phone" booklet, prepared by the Public Relations Division, NZ Post Office, in 1968.)
See also what an early telephone connection cost in 1919.
and The Old Telephones from the same booklet.
The old telephone on the wall - Story.