# What are the numbers on the other side of vernier caliper [closed]

I have an old German caliper. It works and look like any other caliper but on the other side it has a series of numbers ranging from 0 to 61653. What are these?

• It looks like a way to give finer resolution of measurement. On the left it starts @ 0, then the next reading is a 6 on the right side, followed by a 24 of the left & 55 on the right, ... & so on. – Fred Apr 7 '17 at 9:45
• Try making a bunch of measurements with both this and a "modern" caliper and see how the numbers relate. – Carl Witthoft Apr 7 '17 at 13:39
• The scale is logarithmic, so I wouldn't exclude the chance the caliper doubles as a slide rule. – SF. Apr 7 '17 at 15:55
• @SF. you win the nerdjokeoftheweek award – Carl Witthoft Apr 7 '17 at 16:34
• very odd that there appear to be no markings on the center slide. Is it possible the device gets disassembled and flipped over to use this scale? – agentp Aug 7 '17 at 21:35

Attempting to understand, I finally plugged in a few of the first terms in Sloan's. Sequence A033581 for $6n^2$ is a close match to these terms (within manufacturing precision, the exact numbers could have been put on there to match the actual mark position). $6.1n^2$, rounded up is even closer. No constant in front of n^2 fits precisely, but it's a close fit.