2017-08-27 by roylowenthal@...
Probably a liquid crystal thermometer - they were sort of popular a few years ago, I haven't seen one in a while. From what I remember, their main problem was that they didn't jump discretely from one temperature reading to another - there were usually 2 different numbers showing at the same time.
< https://en.wikipedia.org/wiki/Liquid_crystal_thermometer >
Roy