At my semi regular thrift / junk shopping trip I found a Compact Pyromillivoltmeter (or simply Pyrometer) made by Arthur F Smith Co in Rochester NY. I've found reference to it being a new product in Analytical Chemistry 1957 Volume 29 issue 4, 82A.

It's a really cool device, and for $3.99 it became mine. It needs a couple small repairs and looks to be about 10° F high in its measurements. The quick connect clamps on the sensing disk have sheered off and someone attempted a repair with solder, which of course will just melt at the temperatures the pyrometer measures.

Maybe the coolest part of this is that it is completely unpowered. There are no batteries or anything else! It relies on an iron constantan thermocouple to generate a small current. I didn't actually know about constantan before, it is a Copper-Nickel alloy.

After a quick scrub with a small amount of acetone to remove much of the stickiness and a little flux and solder removal and good care its back to perfect working order even after 63 years.