Matthew Bannister on

Dr. Spencer Silver, the American chemist who invented the adhesive used in Post It Notes.

Kevin Jackson, the writer, broadcaster and critic described as a “21st century man of letters”.

Patricia Brown, who played a leading role in cracking German codes at Bletchley Park during the second world war.

Asfaw Yemiru, the former street boy from Ethiopia who founded a school for orphans in Addis Ababa which has given free education to thousands of students.

Producer: Neil George

Interviewed guest: Linda Spencer

Interviewed guest: Art Fry

Interviewed guest: Tom Sutcliffe

Interviewed guest: Iona Brown

Interviewed guest: Dr Tessa Dunlop

Interviewed guest: Beneberu Demissie Kassa

Interviewed guest: Revd Canon Tim Kinahan

Archive clips used: Twenty Minutes_Dutch Icons_Vermeer: Radio 3, TX 8.10.2002; Saturday Review: Radio 4, TX 9.11.2019