bethel vs reredos

bethel

noun
  • A holy place. 

  • A chapel, especially one for sailors, converted from an old ship. 

reredos

noun
  • A screen or decoration behind the altar in a church, usually depicting religious iconography or images, akin to the iconostasis of the Eastern Churches. 

  • The back of an open fire-hearth, in medieval halls. 

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