recondite vs wheels within wheels

recondite

adj
  • Difficult to grasp or understand; abstruse, profound. 

  • Little known; esoteric, secret. 

  • Having mastery over one's field, including its esoteric minutiae; learned. 

  • Deliberately employing abstruse or esoteric allusions or references; intentionally obscure. 

noun
  • A recondite (hidden or obscure) person or thing. 

  • A scholar or other person who is recondite, that is, who has mastery over his or her field, including its esoteric minutiae. 

wheels within wheels

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