baluster vs handrail

baluster

noun
  • A short column used in a group to support a rail, as commonly found on the side of a stairway; a banister. 

handrail

noun
  • A rail which can be held, such as on the side of a staircase, ramp or other walkway, and serving as a support or guard. 

  • A moving continuous belt-like rail on either side of an escalator which users can hold on to for support. 

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