mullion vs paling

mullion

noun
  • A vertical bar between the panes of glass or casements of a window or the panels of a screen. 

verb
  • To shape into divisions by means of mullions. 

paling

noun
  • A fence made of galvanized sheeting. 

  • A pointed stick used to make a fence. 

  • A fence made of palings. 

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