alteration vs point of sail

alteration

noun
  • The act of altering or making different. 

  • The state of being altered; a change made in the form or nature of a thing; a changed condition. 

point of sail

noun
  • A sailing vessel's course in relation to the wind direction. 

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