chamber pot vs crapper

chamber pot

noun
  • A container used for urination and defecation, particularly those used in early modern towns before the advent of the flush toilet. 

crapper

noun
  • A chamber pot or toilet, particularly (dated) a flush toilet by Thomas Crapper. 

  • A rapper, or a performer of rap music. 

  • A lavatory or outhouse. 

  • A half-glass of whiskey. 

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