Big Ben vs chronograph

Big Ben

name
  • The hour bell in the Elizabeth Tower (formerly known as the Clock Tower), adjacent to the Houses of Parliament in Westminster, London, United Kingdom. 

  • The clock tower itself. 

chronograph

verb
  • To make an accurate measurement of the speed of a projectile. 

noun
  • A device which marks or records time or time intervals. 

  • A combination of a watch and a stopwatch. 

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