calumet vs chillum

calumet

noun
  • A clay tobacco-pipe used by American Indians, especially as a symbol of truce or peace. 

chillum

noun
  • A conical pipe used for smoking marijuana, usually made of fired clay, porcelain, soapstone, glass or, more rarely, wood. 

  • The part of such a pipe that contains the tobacco and charcoal balls. 

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