appease vs smooth down

appease

verb
  • To make quiet; to calm; to reduce to a state of peace; to dispel (anger or hatred). 

  • To come to terms with; to adapt to the demands of. 

smooth down

verb
  • To render smooth, to remove roughness from 

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