observatory vs panorama

observatory

noun
  • A lookout (vantage point with a view of the surrounding area) 

  • A place where stars, planets and other celestial bodies are observed, usually through a telescope; also place for observing meteorological or other natural phenomena. 

panorama

noun
  • An unbroken view of an entire surrounding area. 

  • A comprehensive survey. 

  • A picture or series of pictures representing a continuous scene. 

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