life preserver vs sjambok

life preserver

noun
  • A buoyant ring or vest intended to keep a person afloat. 

sjambok

verb
  • To whip with a sjambok; to horsewhip. 

noun
  • A stout whip, especially made of rhinoceros or hippopotamus hide. 

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