Another mystery object

[Neil WyattModerator @neilwyatt]

> Looks like we all got the answer…..

We now await the size of the 'centimetres' with bated breath!

Neil

[Speedy Builder5Participant @speedybuilder5]

Ah well, 1 Cm on the calliper = 1Cm on my modern rule. Over the 10 Cm of the Calliper it measures 99.8 Mm, but I think this may be wear and tear and general abuse of the instrument.

I think that this still leaves us somewhere near Neil's first post, but not quite ! However I do like the patternmakers idea. But why would an 'inch' be divided into twelfths ?

Bob H

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Speedy Builder5 on 06/09/2014 06:52:19:

But why would an 'inch' be divided into twelfths ?

.

Not that uncommon … Old style school rulers had a twelfths scale too.

• 1" to the foot is a useful scale for drawings & models [e.g. Doll's House]
• Twelfths allows access to thirds, which are not available on decimal or binary divisions.

MichaelG.

.

Edit: Very interesting notes about using twelfths, here.

Edited By Michael Gilligan on 06/09/2014 07:31:03

[Michael GilliganParticipant @michaelgilligan61133]

Bob,

Is the scale engraved with the word "Inches" [or whatever], or was that just your reasonable assumption?

MichaelG.

[John McNamaraParticipant @johnmcnamara74883]

Hi All

I remembered that type was based on numbers that divide into 12 so did a little web searching…..
The calliper might have been used to measure type?

**LINK**

**LINK**

Regards
john

[Neil WyattModerator @neilwyatt]

You didn't read the link I gave properly! 12 lignes make up one pouce!

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Neil,

The ligne was [and still is] commonly used by watchmakers.

… unfortunately, none of this explains the scale factor on Bob's calliper.

MichaelG.

[herbert punterParticipant @herbertpunter99795]

French cabinet makers used to use 'French Inches', maybe they still do?

Bert

[Speedy Builder5Participant @speedybuilder5]

We think the clue was "Found in South West France". looking on the web **LINK**

It talks about the 'Toise' and then the Pied de Rois (or foot of the King). This being 32.66 Cm which divided by 12 becomes 2.7216 recurring. Not quite 27.38 mm, however there were regional difference and as SW France is some way from Paris, we think this may be the explanation. But always open to opinion.

BobH

[Neil WyattModerator @neilwyatt]

the later Pied defined by law in 1799 is closer at 27.07

Neil

(Angels and pins?)

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