pram vs wherry

pram

noun
  • A flat-bottomed barge used on shallow shores to convey cargo to and from ships that cannot enter the harbour. 

  • A type of dinghy with a flat bow. 

  • A small vehicle, usually covered, in which a newborn baby is pushed around in a lying position. 

  • A similar barge used as platform for cannons in shallow waters which seagoing warships cannot enter. 

wherry

noun
  • A light ship used to navigate inland waterways. 

  • A flat-bottomed vessel once employed by British merchants, notably in East Anglia, sometimes converted into pleasure boats. 

  • A liquor made from the pulp of crab apples after the verjuice is extracted. 

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