mackinaw vs oilskin

mackinaw

noun
  • A heavy woolen cloth. 

  • A flat-bottomed cargo boat; mackinaw boat. 

  • A blanket made of wool, formerly distributed to the Amerindians by the U.S. government. 

oilskin

noun
  • Cloth made from cotton and treated with oil and pigment to make it waterproof. 

  • A raincoat made from cotton fabric treated with oil and pigment to make it waterproof. 

  • Foul-weather gear worn by sailors, whether of natural or synthetic materials. 

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