Polemoscope: Georgian “Jealousy Glasses”
This article, by author Laurie Benson, originally appeared on her blog, Laurie Benson’s Cozy Drawing Room. It is used here with permission.
Imagine attending a performance at the Theatre Royal, Drury Lane and you discover the object of your affection is sitting in a box to your right. You have no desire to make a spectacle of yourself by leaning out of your box to see who they are with, so you take out what appears to be a straight-barrel spyglass and point it at the stage. While it looks as if you are focusing your attention on the performance, the ingenious spyglass you are holding is allowing you to watch the people in the box to your right. Now you can stare to your heart’s content and no one will be the wiser.
While researching a pair of antique opera glasses this past week, I stumbled across a fun accessory I’d never heard of known as the “jealousy glass.” It looks like a single barrel opera or field-glass, but it actually contains an oblique lens and side aperture that allows the user to discretely see what is happening to their left or right.
The jealousy glass, also known as a polemoscope, was invented by the German-Polish astronomer Johannes Hevelius in 1637. Hevelius believed his invention could have military uses, but the viewing angle was found to be too narrow. During the 18th century, the general population began using the polemoscope to spy on other people.