- Author:
- Lyon Todd
- Adapted by:
- Alistair Bell
- Music arranged by:
- Albert Webb
- Music played by:
- The Albert Webb Trio
- Costumes supervised by:
- Joyce Hawkins
- Make-up supervised by:
- Gwen Arthy
- Designer:
- Michael Edwards
- Script editor:
- Betty Willingale
- Producer:
- Campbell Logan
- Director:
- Julia Smith
- Alexander Graham Bell:
- Alec McCowen
- Thomas Watson:
- Clive Endersby
- Mrs. Hubbard:
- Mary Barclay
- Mabel Hubbard:
- Francesca Annis
- Grace Hubbard:
- Jenny Agutter
- Berta Hubbard:
- Judy Geeson
- Mr. Hubbard:
- John Woodnutt
- Mr. Sanders:
- Peter Carlisle
- George Sanders:
- Michael Crockett
- George Brown:
- Robert James
- Professor Bell:
- John Phillips
- Masters:
- Jack Holloway
- Temple:
- John Bott
- Elisha Gray:
- Warren Stanhope
- Oliver Ringrose:
- Peter Daly
- Jonas:
- Andre Dakar
