Film: 1750

Science | 1960 | Sound | B/W

Synopsis:

A technical explanation of how a telephone works using sound waves and electrical relay.
Boy in uniform at a table listens to a tuning fork. Close up of his ear listening, the fork and animated sound waves. Boy makes a tissue paper and comb sound box and blows it. two schoolboys in a garden with two tin cans and a long string. Close up of the boy's ear and the tin can. Still of Alexander Graham Bell. Model of his original phone system. Explanation of Graham Bell's system with a magnet and diagram. Diagram of modern carbon granule microphone. Sound waves. Speech current. Diagram of a receiver. Superimposed two school boys talking to each other on the phone, you see both boys with a dividing line. Boys demonstrate simple system. Plastic grey dial phone. Demonstration of how the phones are linked with a telephone exchange. Women sit in row at a manual telephone exchange. Plugging in. Close up of plugs and woman with head set. Little girl talks to schoolboy. Line of operators with supervisor. Automatic exchange shown. Boy dials.


To request more details on this film, please contact us quoting Film number 1750.