hand glass vs safety reflector

hand glass

noun
  • A small mirror with a handle. 

  • A small glazed frame for the protection of plants. 

safety reflector

noun
  • A reflector intended for pedestrians, runners, and motorized and non-motorized vehicles. It aids visibility of a person or vehicle as it reflects light from headlights of vehicles. 

How often have the words hand glass and safety reflector occurred in a corpus of books? (source: Google Ngram Viewer )