Pharos vs Tower

Pharos

name
  • The Lighthouse of Alexandria, located on the island Pharos 

  • A small island off Alexandria where the Lighthouse of Alexandria was located. 

Tower

name
  • A habitational surname.; Alternative form of Towers 

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

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

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