
This is an amazing device. It is the old furnace thermostat which has been on the dining room wall since we bought the house back in 1971. I am assuming it was installed with the oil burner. My guess is that all happened in the 1950's or so. This was manufactured by the White-Rogers Company, which fortunately is still in business. Here is what is amazing - this is an entirely mechanical device that works by having a "bimetal coil" which coils or un-coils depending on the temperature, and that in turn opens or closes a single contact, which then tells the furnace to start or to stop. This is a mechanical device which has functioned with no problems, ever, for at least SIXTY years! This mechanical wonder was replaced with a modern digital one, when we had the new gas furnace installed last month. Somehow it seems a shame to replace something that has served us so faithfully for all these years.