earth closet vs gentlemen's room

earth closet

noun
  • An outhouse or lavatory which uses a cesspit rather than a flush toilet and plumbing. 

gentlemen's room

noun
  • A waiting room in a railway station or other public building, often including a separate lavatory. 

  • Any room intended for use by men 

How often have the words earth closet and gentlemen's room occurred in a corpus of books? (source: Google Ngram Viewer )