Overview: From Belfast's City Hall, Magnus Magnusson quizzes Andrew Vaughan (teacher) - life and poetry of Seamus Heaney ; Rosaleen Lavery (customs and excise officer) - 18th-century British pottery and porcelain; Alan Friezer (retired schoolmaster) - history of chemistry until 1915; Howard Dolan (assistant director, CBI) - life and times of Franklin D Roosevelt.