cropping vs telescoping

cropping

noun
  • The act by which something is cut short or truncated. 

  • An outcrop that is mined for the ore it contains. 

  • The growing of crops. 

telescoping

noun
  • The act of extending or contracting in the manner of a telescope. 

  • A telescopic action. 

  • Extending limited data to make up for gaps 

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