Zeppelin vs hot-air balloon

Zeppelin

noun
  • A type of large dirigible rigid airship of the early 20th century, built by the German Luftschiffbau Zeppelin and designed to carry passengers or bombs. 

  • A rigid airship dirigible, not restricted to Germany nor the early 20th century. 

name
  • A German manufacturing company, famed for building the zeppelin airships. 

hot-air balloon

noun
  • A balloon-shaped aircraft whose bag is inflated with hot air; it carries passengers and crew in a gondola slung underneath. 

How often have the words Zeppelin and hot-air balloon occurred in a corpus of books? (source: Google Ngram Viewer )