sextant vs telescope

sextant

noun
  • A navigational device for deriving angular distances between objects so as to determine latitude and longitude. 

  • One sixth of a circle or disc; a sector with an angle of 60°. 

  • One of six groups of adjacent teeth, excluding the wisdom teeth. The front sextants go from canine to canine, and there are sextants on the right and left of these. See w:Periodontal examination. 

telescope

noun
  • Any instrument used in astronomy for observing distant objects (such as a radio telescope). 

  • A monocular optical instrument that magnifies distant objects, especially in astronomy. 

  • A retractable tubular support for lights. 

verb
  • To collapse, via cancellation. 

  • To extend or contract in the manner of a telescope. 

  • To slide or pass one within another, after the manner of the sections of a small telescope or spyglass. 

  • To come into collision, as railway cars, in such a manner that one runs into another. 

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