Scale Buoy, Patent Number 391 865, with copper alloy stand and glass base for stand, unsigned, British, 1930-1940. It was claimed that the use of a Scale Buoy could prevent scale in a boiler. Scale Buoy 1930-1940
Scale Buoy, unsigned, British, 1930-1940. It was claimed that the use of a Scale Buoy could prevent scale in a boiler. Scale Buoy, which the use of was claimed could prevent scale in a boiler 1930-1940