Pocket watch Crystal Fractional numbers?

kingleo59

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Feb 21, 2021
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Can someone please explain to me what those little stickers with various numbers and fractions mean? Typically there is a number and a fraction behind it and then a number below that it can be either smaller or bigger with another fraction and then sometimes there’s a whole number below that? I am including photos of a few crystals as examples. What I’m trying to find out is how you decipher those numbers and make use of them. I am finding crystals ,from the thousand that I have that are new old stock ,by trial and error.Please help. CACD0668-E779-4CD3-A322-34F73EFA6795.jpeg CACD0668-E779-4CD3-A322-34F73EFA6795.jpeg 2842298C-1A5B-4728-9BB1-FD1F92B71E90.jpeg 648B4F49-A4D8-4971-B39D-3351CC2D45D4.jpeg
 

agemo

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Apr 5, 2011
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Hi,
Let's take the example of glass 21 8/16, 23 being a classification number.
21 is equal to 21 lines or 21x 2,256 = 47,376 millimeters.
8/16ths equals half a line = 1.128 millimeters

The glass measures 47.376 + 1.128 = 48.504 millimetres

These are simply old measures that have not been used since the beginning of the 20th century.
réduc lignes.jpeg

Amicalement GG
 

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