caisson vs snuffbox

caisson

noun
  • A large box to hold ammunition. 

  • A chest filled with explosive materials, used like a mine. 

  • A two-wheeled, horse-drawn military vehicle used to carry ammunition (and a coffin at funerals). 

  • A floating tank that can be submerged, attached to an underwater object and then pumped out to lift the object by buoyancy; a camel. 

  • An enclosure from which water can be expelled, in order to give access to underwater areas for engineering works etc. 

  • The gate across the entrance to a dry dock. 

  • A coffer. 

snuffbox

noun
  • A small box or container to hold snuff or loose tobacco. 

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