Looks like a radiator thermostat... Why they'd use a socket to hold it open, I can't understand. I assume it's not actually welded, it's just a nice fillet of rust buildup.
Do you think in the early 1900s they were making jokes about people born in 1899 as being born in the 1800s?
-You were born in the 1800s? You must be ancient!
-That joke's not funny anymore. I'm only 2 years older than you, Dale.
In approach of that day, one of the supervisors found a 10 hour loop of that song on youtube and played it in his office. Anybody who went in there looking for him had their ears assaulted until they decided they'd had enough and left.