cold frame vs conservatory

cold frame

noun
  • A transparent-roofed enclosure, built low to the ground, used to protect plants from cold weather. 

conservatory

noun
  • A large greenhouse or hothouse for the display of plants 

  • A school of music or drama 

  • A storehouse. 

  • A glass-walled and -roofed room in a house 

adj
  • Relating to conservation. 

  • Having the quality of preserving from loss, decay, or injury. 

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