barbed wire vs railing

barbed wire

noun
  • Twisted strands of steel wire, often coated with zinc, having barbs evenly spaced along them; used to construct agricultural and military fences. 

railing

noun
  • A fence or barrier consisting of one or more horizontal rails and vertical supports. 

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