chimney pot vs churchwarden

chimney pot

noun
  • A short earthenware pipe, placed on top of a chimney to improve the draft. 

churchwarden

noun
  • A churchwarden pipe. 

  • A lay officer of the Church of England who handles the secular affairs of the parish. 

  • A similar functionary of the Episcopal church. 

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