altar vs sacristy

altar

noun
  • A raised area around an altar in a church; the sanctuary. 

  • A table or similar flat-topped structure used for religious rites. 

  • Any (real or notional) place where something is worshipped or sacrificed to. 

sacristy

noun
  • A room in a church where sacred vessels, books, vestments, etc. are kept. Sometimes also used by clergy to prepare for worship or for meetings. 

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