metronome vs timepiece

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. 

timepiece

noun
  • Any device that measures or registers time; a clock or watch, especially one lacking a chime or other striking mechanism. 

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