cotter vs hook and eye

cotter

noun
  • A pin or wedge inserted through a slot to hold machine parts together. 

  • A peasant who performed labour in exchange for the right to live in a cottage. 

  • A cotter pin. 

verb
  • To fasten with a cotter. 

hook and eye

noun
  • A matched hook and an eye (loop into which the hook can fit), used for fastening. 

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