What is a saggarmaker's bottom knocker? What's My Line? was a Classic British television panel game from the 's. Contestants with unusual occupations.
A SAGGAR is a fireclay container, usually oval or round, used to protect pottery from marking by flames and smoke during firing in a bottle oven. The SAGGAR.
saggar maker's bottom knocker (plural saggar maker's bottom knockers). A young boy employed to make the base of a saggar from a lump of fireclay, knocking it.