piling vs summertree

piling

noun
  • A structural support comprising a length of wood, steel, or other construction material. 

  • The act of heaping up. 

  • The process of building up, heating, and working fagots or piles to form bars, etc. 

summertree

noun
  • A horizontal beam brought even with the face (breast) of a wall, to support a wall above a gap or opening; a beam bearing a load above. 

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