set in stone vs unsteady

set in stone

verb
  • To render something permanent, certain, or firm. 

adj
  • Permanent; certain; firm. 

unsteady

verb
  • To render unsteady, removing balance. 

adj
  • Inconstant in purpose, or volatile in behavior. 

  • Lacking regularity or uniformity. 

  • Not held firmly in position, physically unstable. 

How often have the words set in stone and unsteady occurred in a corpus of books? (source: Google Ngram Viewer )