brougham vs landau

brougham

noun
  • A four-wheeled horse-drawn carriage, designed in 1839. It had an open seat for the driver in front of the closed cabin for two or four passengers. 

  • An automobile, a sedan without a roof over the driver's seat. 

landau

noun
  • A type of lightweight, four-wheeled carriage in which the front and back passenger seats face each other. 

  • A style of automobile based around the design of landau carriages. 

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