Here is a neat item I recently acquired along with a glass crystal cabinet. I had heard these existed but never saw one until now. It is an antique sight gauge for sizing round glass crystals. The gauge grid is engraved with 16 vertical lines interesected by 25 sloping lines.

You just put your crystal on the gauge up against the bottom rail (see pic) and then roll it around until you find a spot where the top edge exactly matches one of the sloping lines.

Then you can read off the ligne size on the vertical scale and the sixteenths of a ligne on the horizonal scale. How cool is that?

IMHO this type of gauge is more accurate and faster than the caliper type gauges I have used before.

It appears to be brass and is quite dirty. Any suggestions on how best to clean it?

V.T.F. Glass Crystal Gauge

Here is how the gauge works. To illustrate I used a typical 16 size crystal of a known size.

Notice where the sloping line exactly matches the edge, that sloping line goes thru 19 on the vertical scale and the vertical line where it matches is the 3rd line from the left, which goes thru 3 on the horizontal scale. Look at the image below and you will see the intersecting lines circled in red.

Hence the size is 19 3/16 ligne, as indeed this crystal is marked.

Crystal Gauge in Use

Aloha Edward

Flitz will work.

Scott