foment vs steam up

foment

verb
  • To apply a poultice to; to bathe with a cloth or sponge. 

  • To incite or cause troublesome acts; to encourage; to instigate. 

noun
  • Fomentation. 

steam up

verb
  • To become coated with condensation. To fog up. 

  • To become steamy. 

  • To bring (a steam boiler) up to working steam pressure. 

How often have the words foment and steam up occurred in a corpus of books? (source: Google Ngram Viewer )