photoplay vs silent film

photoplay

noun
  • A theatrical play that has been filmed for showing as a movie. 

  • A novel adapted from a movie and illustrated with photographic stills taken from the film. Usage largely confined to the silent era of Hollywood. 

silent film

noun
  • A film with no synchronized recorded sound, especially spoken dialogue. 

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