bathtub vs washbowl

bathtub

noun
  • A large container for holding water in which a person may bathe (take a bath). 

washbowl

noun
  • A sink in a bathroom, connected to a supply of water and a drain, in which one may wash one's face and hands. 

  • A basin for washing the face and hands; a washbasin. 

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