beast of burden vs sumpter

beast of burden

noun
  • A draught animal, such as a donkey, mule, llama, camel, horse, or ox, that carries or pulls a load for the benefit of a human. 

  • Any domesticated animal trained to perform tasks for humans, such as a herding dog or trained falcon. 

sumpter

noun
  • A packhorse; a beast of burden. 

  • The driver of a packhorse. 

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