discover vs make known

discover

verb
  • To question (a person) as part of discovery in a lawsuit. 

  • To find or learn something for the first time. 

  • To create by moving a piece out of another piece's line of attack. 

make known

verb
  • To disclose (a secret). 

  • To announce (some information) generally. 

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