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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Click on the images for a larger version.
… Ceramics …
FanHsiu has a Dennert & Pape Didier-Stettin Keramik Rechenschieber
and wonders: what is the function of the A1, A2, S1 and S2 scales?
More images in the OS Galleries
… 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
KRING-member Meine van Essen has solved this mystery. See MIR 94, p.14–18.
… 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
… inconvenient Matthijssen slide rules …
Why are the B and C scales not positioned at the edge of the slide?
What do the gauge marks tell about the application of these slide rules?
See: Otto van Poelje, “Two Matthijssen slide rules with many questions” MIR 62 p.23-25
| Mark | 0,8/55 | 1,0/43 | 0,7/55 | 1,0/35 | 0,8/43 | 0,7/43 | 0,8/35 | 0,5/55 | 1,0/25 | 0,7/35 | J60 | 0,5/43 | 0,8/25 | 150P | 0,7/25 | 0,5/35 | 0,5/25 | J210 | 1,0/55 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Value | 352 | 344 | 308 | 280 | 274 | 240 | 224 | 220 | 200 | 196 | 1885 | 172 | 160 | 150 | 140 | 140 | 100 | 660 | 440 |
| Mark | 70/8 | 75/8 | 25/3 | 90/10 | 30/4 | 100/13 | 120/14 | 130/15 | 40/5 | 150/16 | 45/6 | 50/6 | 60/7 | 65/8 | 70/8 | 75/8 | 25/3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Value | 380 | 351 | 284 | 2362 | 1785 | 1655 | 1273 | 1094 | 1071 | 886 | 796 | 712 | 508 | 412 | 380 | 351 | 282 |
| Mark | 200/100-16 | 45/30-5 | 150/100-13 | 160/80-13 | 150/75-10 | 120/80-10 | 130/65-10 | 100/65-9 | 90/65-8 | 100/50-8 | 75/65-8 | 80/40-8 | 75/50-7 | 65/50-6 | 60/40-6 | 200/100-16 | 45/30-5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Value | 359 | 277 | 243 | 233 | 169 | 150 | 146 | 1115 | 930 | 905 | 835 | 708 | 655 | 507 | 445 | 359 | 277 |
… 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
… linear 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