black as Newgate's knocker vs ebon

black as Newgate's knocker

adj

  • Completely black in colour. 

ebon

adj

  • Black in colour. 

  • Made of ebony. 

noun

  • Ebony; an ebony tree. 

How often have the words black as Newgate's knocker and ebon occurred in a corpus of books? (source: Google Ngram Viewer )