horsepower vs intensity

horsepower

noun
  • Strength. 

  • Power derived from the motion of a horse. 

  • A nonmetric unit of power (symbol hp) with various definitions, for different applications. The most common of them is probably the mechanical horsepower, approximately equal to 745.7 watts. 

  • A metric unit (symbol often PS from the German abbreviation), approximately equal to 735.5 watts. 

intensity

noun
  • The degree of strength. 

  • Time-averaged energy flux (the ratio of average power to the area through which the power "flows"); irradiance. 

  • Can mean any of radiant intensity, luminous intensity or irradiance. 

  • Synonym of radiance. 

  • The quality of being intense. 

  • The severity of an earthquake in terms of its effects on the earth's surface, and buildings. The value depends on the distance from the epicentre, and is not to be confused with the magnitude. 

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