Mysterious calculating instruments
Members of the KRING regularly encounter calculation instruments whose origin or use is unclear.
Can you help us solve these mysteries?
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… Nato stocknr: 6B-5036 / Doc.nr 680701 / Inspectiedatum 4-1-61 …
A solar compass? For a Starfighter?
Both the Zonnewijzerkring and the Kring Historische Rekeninstrumenten can't figure it out.
See: Andries de Man, “Instrument for Starfighters” MIR 91 p.31
… Aristo 10063, designed in 1951 by Dr. Ing. Luetgebrune for Continental …
Is this a slide rule for tire design? How does it work?
Is it related to the Aristo 90187 Reifenrechenstab?
See also: Klaus Kühn, Karl Kleine, “Dennert & Pape, ARISTO 1872 - 1978”
& animation
… 17th/18th century abacus from the Gdansk National Museum…
Is this really an abacus?
See: Henk Peters, “Mystery object: an abacus?” MIR 75 p.12–14
… the enormous collection of the Land Registery Museum contains this small black slide rule…
Where does this slide rule come from?
What was its purpose?
Is there a reason the slider can only slide to the left??
See: Otto van Poelje, “Mystery black slide rule in the Land Registery Museum” MIR 61 p.20-22
… a hardboard pocket slide rule …
Who made this strangely sized pocket slide rule from an unusual material?
Does this have anything to do with the “Demoulin” company?
Or with Graphoplex?
See: Otto van Poelje, “A puzzle for readers” MIR 59 p.10-11
… cercle mystère …
Prototype? One-off? Do we see the hand of Paul Pouech?
See: Ronald van Riet, “Mysterious Circles” MIR 58 p.32
… lineair non-linear scales …
Why would you do trigonometry for only three specified radii?
See: Otto van Poelje, “Mystery ruler from Kleman with transversal scales for sinus and chord” MIR 55 p.21-22