firing vs porcelain

firing

noun
  • The process of applying heat or fire, especially to clay, etc., to produce pottery. 

  • Cauterization. 

  • The dismissal of someone from a job. 

  • The fuel for a fire. 

  • The discharge of a gun or other weapon. 

  • The act of adding fuel to a fire. 

porcelain

noun
  • A hard white translucent ceramic, originally made by firing kaolin, quartz, and feldspar at high temperatures but now also inclusive of similar artificial materials; also often (figurative) such a material as a symbol of the fragility, elegance, etc. traditionally associated with porcelain goods. 

  • Synonym of cowrie. 

  • Synonym of china: porcelain tableware. 

  • A kind of pigeon with deep brown and off-white feathers. 

  • An object made of porcelain, (particularly) art objects or items of tableware. 

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