feel out vs glimpse

feel out

verb
  • To try to ascertain a person's point of view, or the nature of a situation, by cautious and subtle means. 

glimpse

verb
  • To see or view briefly or incompletely. 

  • To appear by glimpses. 

noun
  • A brief look, glance, or peek. 

  • A sudden flash. 

  • A faint idea; an inkling. 

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