carburetor vs sprinkler head

carburetor

noun
  • A water pipe or bong; a device or contrivance for mixing air with burning cannabis or cocaine. 

  • A device in an internal combustion engine where fuel is vaporized and mixed with air prior to ignition. 

sprinkler head

noun
  • A heat-activated device that sprays water in the event of a fire, usually mounted on a ceiling. 

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