• 
  Francesca Annis

  Mabel Hubbard
• 
  Jenny Agutter

  Younger sister
• 
  Judy Geeson
• 
  Archie Duncan

  Mr. Tweedie
• 
  Alec McCowen

  Alexander Graham Bell
• 
  Clive Endersby

  Thomas Watson

• 
  Joyce Hawkins

  costume
• 
  Betty Willingale

  miscellaneous crew