clarion vs watch glass

clarion

noun
  • An organ stop consisting of pipes with reeds giving a high-pitched note like that of a clarion (sense 1). 

  • A charge thought to represent a type of wind instrument, a keyboard instrument like a spinet, or perhaps a rest used by a knight to support a lance during jousting. 

  • A medieval brass instrument chiefly used as a battle signal; related to the trumpet, it had a narrow, straight pipe and a high-pitched, piercing sound. 

  • The sound of a clarion (sense 1), or any sound resembling the loud, high-pitched note of a clarion. 

verb
  • To announce or herald (something) using a clarion (noun sense 1). 

  • Of a thing: to cause (a place) to echo with a sound like that of a clarion. 

  • To sound a clarion; also, to make a high-pitched, piercing sound like that of a clarion. 

  • To announce or herald (something) clearly, especially so as to stir or unite people. 

adj
  • Of a sound, a voice, a message, etc.: brilliantly clear. 

watch glass

noun
  • An item of glass laboratory equipment consisting of a simple, slightly concave circle of glass. It is a general utility item, used to hold small samples, to evaporate liquids, to cover a beaker, and so on. 

  • A sandglass. 

  • The glass covering of the face of a watch. 

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