radiograph vs radiography

radiograph

noun
  • An instrument for measuring and recording solar radiation. 

  • An image, often a photographic negative, produced by radiation other than normal light; especially an X-ray photograph. 

verb
  • To produce a radiograph image. 

radiography

noun
  • the process of making radiographs, and the science of analyzing them 

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