lath vs purlin

lath

noun
  • A thin, narrow strip, fastened to the rafters, studs, or floor beams of a building, for the purpose of supporting a covering of tiles, plastering, etc. 

  • Microscopic, needle-like crystals, usually of plagioclase feldspar, in a glassy groundmass 

verb
  • to cover or line with laths 

purlin

noun
  • A longitudinal structural member bridging two or more rafters of a roof. 

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