I had to do this................

On what's sliding, I've concluded it's /metal/ and /solid/. It also sounded like it's not square or round but rather elongated -- it doesn't roll, it slides. So it could be a wrench, it could be a bolt, it's not a nut, and it's not Mercury. I'm sure our thermometers are driven by thermistors. ;]

On the temperature reading, I suspect we all need a software update. Anyone who hasn't noticed the 90's for 40's is probably in a warm climate. It just lights one extra bar on the top of the 4 making it a 9... On the bright side, it seems to be accurate if you account for this.