batten down vs close down

batten down

verb
  • To prepare for adversity. 

  • To close or make watertight, referring to hatches and cargo. 

  • To secure. 

close down

verb
  • To surround someone, as to impede their movement. 

  • To stop trading as a business. 

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