glassichord vs verrillon

glassichord

noun
  • A 19th-century musical instrument made of glass plates that are struck by hammers or sticks. 

  • Synonym of glass harmonica 

  • Anything that produces a similarly pure continuous sound. 

verrillon

noun
  • The glass harp: a musical instrument consisting of an array of glasses filled with varying amounts of water, played by rubbing one's fingers around the rims of the glasses. 

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