encourage vs kindle

encourage

verb
  • To mentally support; to motivate, give courage, hope or spirit. 

  • To spur on, strongly recommend. 

  • To foster, give help or patronage 

kindle

verb
  • To arouse or inspire (a passion, etc). 

  • To begin to grow or take hold. 

  • To start (a fire) or light (a torch, a match, coals, etc.). 

  • To bring forth young; to give birth. 

adj
  • pregnant 

noun
  • A group of kittens. 

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