hourglass vs speedometer

hourglass

noun
  • A cursor, often shaped like an hourglass, indicating that the computer is busy. 

  • A clock made of two glass vessels connected by a narrow passage through which sand flows. 

speedometer

noun
  • Such a device incorporating an odometer. 

  • An instrument located within the dashboard of a vehicle that measures and indicates the current speed of the vehicle. 

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