come upon vs uncover

come upon

verb
  • To discover or find, especially by chance or accident. 

  • To befall; to affect; to happen to. 

uncover

verb
  • To reveal the identity of. 

  • To remove one's hat or cap as a mark of respect. 

  • To expose the genitalia. 

  • To remove a cover from. 

  • To show openly; to disclose; to reveal. 

  • To expose (lines of formation of troops) successively by the wheeling to right or left of the lines in front. 

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