brass knuckles vs epee

brass knuckles

noun
  • A weapon consisting of a metal reinforcement for the clenched fist, with finger holes molded in. 

epee

noun
  • A sharp-pointed dueling sword with a bell-shaped guard, used (with the end blunted) in sport fencing. 

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