hammering vs palpitation

hammering

noun
  • A period of being beaten or hammered. 

  • A heavy defeat. 

  • A dented appearance on silverware, produced by successive blows of a hammer. 

palpitation

noun
  • An abnormal beating of the heart that may be perceived by the patient, a result of excitement, exertion, or illness. 

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