gazebo vs orangery

gazebo

noun
  • A belvedere, either a type of summer-house or a roofed, detached porch-like structure, usually in a yard, park or lawn. 

orangery

noun
  • A greenhouse in which orange trees are grown. 

  • A garden or plantation where orange trees are grown. 

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