frontispiece vs proscenium

frontispiece

noun
  • A façade, especially an ornamental one. 

  • An illustration that is on the page before the title page of a book, a section of one, or a magazine. 

  • A small ornamental pediment, especially at the top of a window or door. 

verb
  • To supply with a frontispiece. 

proscenium

noun
  • A proscenium arch. 

  • The stage area between the curtain and the orchestra. 

  • The stage area immediately in front of the scene building. 

  • The row of columns at the front the scene building, at first directly behind the circular orchestra but later upon a stage. 

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