metronome vs timer

metronome

noun
  • A device, containing an inverted pendulum, used to mark time by means of regular ticks at adjustable intervals; an electronic equivalent that emits flashes. 

timer

noun
  • A device used to measure amounts of time. 

  • Any electronic function that causes a device to be able to do something automatically after a preset amount of time. 

  • A person who records the time elapsed in a sporting event. 

  • One who has done something a certain number of times. 

  • One characterized by a certain time or time frame, such as their work hours. 

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