Sunday, June 25, 2023

Columbus bilateral letter-scale - repaint and polish

After a repaint and a polish, this little bilateral Columbus letter-scale is very shiny.

This one, like many, looked rather dejected. The brass was severely tarnished from old attempts at cleaning that removed the old lacquer and the cast-iron base was rusty. The pins that hold it all together can however be pulled-out fairly easily to be able to clean-up the individual parts.

The base got to join in the paint-stripping session last week:

The decorations of the base are best visible in the grey primer, just before getting a new coat of glossy black. 

The brass was polished-up, with the remnants of the original lacquer finish removed from the front-face of parts. After polishing, the brass parts were again given a coat of clear varnish to seal the surface as was done originally. Lacquer closes-off the surface to oxygen, stopping or at least slowing down tarnishing.

These small bilateral scales still show up on local classified sites - many were made and they are of course really durable. This Columbus letter-scale was made by the Ph. J. Maul company of Hamburg, Germany. The Maul company made many and diverse scales for over a century - and also made this one, as seen from their trademark on the linkages.

These bilateral scales don't need adjusting against a sloping desk. Because the weights move out symmetrically, it is automatically compensated. This bilateral scale is made to a design that was patented in Germany in 1904. 

This German patent 167,192 was however not by Maul, but by Automat AG in Berlin. The drawings in the patent do illustrate the design, as does the claim of two symmetrical weights rotating on a single axis. 

Possibly that Maul either took a license, or more likely completely took over the production of the Columbus-brand scales of this design from Automat.

Most of these have a brass weighing platform, this one however had a brassed mild-steel platform. The plating was partly gone and the metal rusted. The whole platform was sanded smooth and also painted gloss-black. This is not the original finish but it looks ok again. More importantly, the weight of the platform is not changed too much, so it still weighs correctly.

Perhaps the plated platform is a hint that it was made when brass was relatively costly, perhaps around 1917 to '19 or perhaps during the chaos of 1923. At any rate, it likely is at least a century old.

With small dabs of red paint on the pointers this little device is again good for another century of use. (It has a good chance to outlive the existence of actual letters and postage stamps, but will still weigh things just fine :-)

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