escalator vs upsurge

escalator

noun
  • Anything that escalates. 

  • An escalator clause. 

  • A motor-driven mechanical device consisting of a continuous loop of steps that automatically conveys people from one floor to another. 

  • An upward or progressive course. 

upsurge

noun
  • A sudden strong rise or flow. 

verb
  • to surge up, or to become stronger or greater 

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