These brewing machines are incredibly durable.
The other day I discovered a wall-mounted two-pot coffee brewer built by the Württembergische Metallwarenfabrik WMF.
It still works like a charme and brews excellent coffee!
See that box attached to the left with that glowing switch? They told me that this is the heating element for the water and that it works with mercury.
I‘m not so sure if it really uses mercury for heating (as they implied) but that it rather has a mercury thermostat for regulating the heat.