Tower vs big house

Tower

name
  • The Tower of London, especially seen as a place of imprisonment or punishment. 

  • A habitational surname.; Alternative form of Towers 

noun
  • Denoting the system of weights used by the Saxon and Norman English kings in their minting of coins. 

big house

noun
  • Used other than figuratively or idiomatically: see big, house. 

  • A religious building of the Delaware Indians, representing the cosmos. 

  • Prison, jail. 

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