collier vs topman

collier

noun
  • A sailor on such a vessel. 

  • A non-traveller. 

  • A person in the business or occupation of producing (digging or mining) coal or making charcoal or in its transporting or commerce. 

  • A vessel carrying a bulk cargo of coal. 

topman

noun
  • The man stationed in the top on a sailing vessel, responsible for the setting of the sails 

  • The uppermost sawyer in a sawpit; a topsman. 

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