invention vs old saw

invention

noun
  • The act of inventing. 

  • Something invented. 

  • The capacity to invent. 

  • A small, self-contained composition, particularly those in J.S. Bach’s Two- and Three-part Inventions. 

old saw

noun
  • A cliché, saying, or overused expression; especially a proverb or maxim. 

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