| Description | Monochrome photograph of a recording of an echo from the aircraft carrier 'Courageous', with a drawing explaining the recording. Also includes 1 colour photograph of an artist's impression of the Avro Anson, with a message from Hanbury Brown to 'Amelia' (probably the television producer Amelia Hann, who was involved in the production of the 1998 BBC programme 'Science at war'). |