mains vs spark

mains

noun
  • The domestic electrical power supply. 

  • The pipes of a centralized water supply that transport the water to individual buildings. 

  • The farm attached to a mansion house. 

  • The main course of a meal. 

spark

noun
  • An electrician. 

  • A small, shining body, or transient light; a sparkle. 

  • Any of various lycaenid butterflies of the Indomalayan genus Sinthusa. 

  • A small amount of something, such as an idea or romantic affection, that has the potential to become something greater, just as a spark can start a fire. 

  • A small particle of glowing matter, either molten or on fire. 

  • A ship's radio operator. 

  • A short or small burst of electrical discharge. 

  • A gallant; a foppish young man. 

  • A beau, lover. 

verb
  • To shoot; to fire 

  • To trigger, kindle into activity (an argument, etc). 

  • To give off a spark or sparks. 

  • To light; to kindle. 

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