housing vs topsail

housing

noun
  • That portion of a mast or bowsprit which is beneath the deck or within the vessel. 

  • A mechanical component's container or covering. 

  • Residences, collectively. 

  • A niche for a statue. 

  • A houseline. 

  • A cover or cloth for a horse's saddle, as an ornamental or military appendage; a saddlecloth; a horse cloth; in plural, trappings. 

  • The activity of enclosing something or providing a residence for someone. 

  • An appendage to the harness or collar of a harness. 

  • The space taken out of one solid to admit the insertion of part of another, such as the end of one timber in the side of another. 

topsail

noun
  • In a fore-and-aft-rigged sailing boat, the sail that is set above the gaff at the top part of the mast. 

  • A sail or either of the two sails rigged just above the course sail and supported by the topmast on a square-rigged sailing ship. 

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