This is a voltmeter that probably was mounted on some sort of machine. It is made from cast iron . Two big copper strips with bolts, to connect the wires, stick through the red baseplate. I have no further information.
The circuit consists of a big 1,1474 H coil (1500 ohm DC resistance ) and a 14.222k wirewound resistor in series. The meter needs to be adjusted. It reads correct when laying flat but reads to high standing right up. There are no adjustment posibillities as far as I can see.
I have not opened the metal u-form metal tube.