batten down vs tie down

batten down

verb
  • To secure. 

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

  • To prepare for adversity. 

tie down

verb
  • to secure as if with a rope or hook. 

  • to constrain, or to confine within set limits. 

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