chimney stack vs furnace

chimney stack

noun
  • A vertical structure, normally of brick, rising from a roof, containing one or more flues, each one terminating in a chimney pot. 

furnace

noun
  • A device that provides heat for a building; a space heater. 

  • A place or time of punishment, affliction, or great trial; severe experience or discipline. 

  • Any area that is excessively hot. 

  • An industrial heating device, e.g. for smelting metal or baking ceramics. 

verb
  • To heat in a furnace. 

  • To exhale like a furnace. 

How often have the words chimney stack and furnace occurred in a corpus of books? (source: Google Ngram Viewer )