flue vs lum

flue

noun
  • An enclosed passageway in which to direct air or other gaseous current along. 

  • A pipe or duct that carries gaseous combustion products away from the point of combustion (such as a furnace). 

  • In an organ flue pipe, the opening between the lower lip and the languet. 

lum

noun
  • A ventilating chimney over the shaft of a mine. 

  • A chimney; also, the top part of a chimney. 

  • A deep pool, especially one in a riverbed. 

  • A grove or wood; also, a woody valley. 

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