That Strange Calculator Again

Probably worth saying, since it's been mentioned again - I'm quite sure this has nothing to do with music in any way; none of the numbers bear any resemblance to acoustic physics.

The thing that puzzles me still is the holes in the two dials. The holes in the inner dial are clearly a detent, but the ring of larger holes doesn't seem a sensible way of making a dial that would just be rotated about as in a circular slide rule. So was something inserted in those holes, or was something visible through the holes?

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From the previous discussion : The dimensions are ~5.125" X 5.125" X .375".

… so my assumption was … a finger-tip

MichaelG.

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Ref. post by Charles Dunham :

 https://www.model-engineer.co.uk/forums/postings.asp?th=171761&p=2

Edited By Michael Gilligan on 15/01/2022 18:45:39

Yes = I think the larger, blind holes are simply to take a finger-tip or the back end of a pencil, as in the old rotary telephone dials.

The video referred to earlier on shows someone rotating the dial but and manipulating the inner one but that doesn't really help us identify it, I'm afraid. It does show the two rotors are not geared together. Or if they were, it might have been by pins lost long ago. It also shows that at certain points certain holes line up, by revealing the writing-pad under the instrument. Unfortunately the operator had apparently no spotted it, and was turning it too rapidly for me to read it properly.

I've had a reply from the pharmacology historians.

They say it's not to do with medicine - adding that to music and textiles as trades it's not for. They did though suggest something I don't think has been looked at yet, that the instrument is not for working in one system, but for converting between two systems of... what? A measurement system now lost?

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Start a new dig......

For example, one Vedro of water = 2.7 Imperial Gallons, as does 1 Eimer; but 1 Pood = 3.6 Imp. Gall.; and the Russian Fathom = 7 feet.

(I kid thee not: look in your copy of Fowler's Mechanics' & Machinists' Pocket Book, 1944. Page 30. )

Further rooting established the vedro and pood were Russian; the eimer, Austrian.

My source? I typed those three names and the word "measurement" into the search-bar and as much by luck as intelligent(!) guess, picked on A Manual of Commerce, by William Waterston.

The Google ad (which offers a printed version of this 19C book) opened a table titled General Table of Metrical Equivalents - to Imperial units. Note the adjective does not say or mean "metric". My choice of units was helpfully highlighted.

Only, Waterston gives the Eimer as 12.460 Imp. Gall in Austria, 15.118 Imp Gall in Prussia... While in Russia, 1 Pood was a mass unit = 36.10lbs avoirdupois ("have some peas" ). Ah - that makes sense: 1 Gall weighs 10lbs.

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Were all these national units undergoing massive revisions even domestically by the 1944 date of Fowler's? It would be logical even without the late-19 and early-20C upheavals across Europe; and Waterston showing for example the Prussians and Rhinelanders had the Morgen (Ger. = "morning"?) for land area, but at 2.63 and 2.10 acres, respectively; while Austria used the Joch (1.42 acres)!

If you scroll up through the bewildering assortment shown in the sample pages, you find metrical evolution occurring in many lands even before the end of the 19C, and the Metric System was already making inroads. France herself invented the metre etc. because, as did other nations, she had suffered a centuries-old trade-by-region measurements conglomerate making even internal commerce increasingly difficult.

France was already metric as we know it, and it's hardly surprising their neighbours especially moved to copy post-Revolutionary France's m,g,l system. Yet she was still though one of several maritime countries using latitude variants of the League whose one length varied by country for nautical distances. For example, her sailors used:

Lea. 1º [divided by] 25. (The standard Nautical Mile now is 1º / 60.)

France also had a "myrametre" = 10km.

At least Britain's engagingly eccentric Imperial units were nation-wide; and the bushel, peck, grain etc were disappearing long before the official move to Metric, now SI, units. Though it lingers: the modern US Gallon was aapparently a 17C Old World, wine-trade version of the Gallon. 

So although this does not really get us much further forwards in identifying our neat little device, it does suggest it was really a units converter for merchants generally; but specific to two nation's national metrical or indeed currency units. Waterston shows currency too, was a complete tangle.

Which countries though?
The table shows an incredible labrynth.

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Interesting that the decimal fractions above are 9s-based but I am not sure if or how they go with the fractions on our curio's scale. We'd need know, really, how the Eimer, Vedro, Pood etc. or other candidate units were sub-divided or multipled. Nor does it explain the 16-times table, but if this device is to suit a national scale, that might not be Russian or Austrian anyway.

Further ferreting, another book - Encylopedia of Scientific Units, Weights and Measures, Francoise Cardarelli, 2012. The Google review frustratringly omits the Russian page but does give a selection of other countries' ancient measures, in tables showing their sub-divisions and multiples. Intriguingly, very many did use ratios expressed (as indeed does Avoirdupois) in single-integer fractions; and some seem to match some of those on this calculator.

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So I for one, inspired by the pharmacologists, am turning to thinking this was a units- or currency- converter for general commerce between two countries, not a special design tool.

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Ref:

https://books.google.co.uk/books?id=2ZUTtLOHd1MC&pg=PA186&lpg=PA186&dq=vedro,+eimer,+pood+measurements&source=bl&ots=qntGtNswHe&sig=ACfU3U3KPmH_T-CGdOCwpBLcw1A8fCG4fA&hl=en&sa=X&ved=2ahUKEwiM7_DKurj1AhUSmVwKHU-XD74Q6AF6BAgeEAM#v=onepage&q=vedro%2C%20eimer%2C%20pood%20measurements&f=false

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Edited By Nigel Graham 2 on 17/01/2022 11:08:19

Relating to Dave's observation posted 15/1 - "The inner ring holes are all dimples, except the video shows one of them, No 30 under the spring clip in the photo, to be a through hole that sometimes aligns with another hole inside".

This thing continues to intrigue me as it does many of you. If you download the video clip and then stick it into an editor, you can both enlarge and step through it. I agree with Dave that one anomoly is the ' 30 ' detent position on the inner wheel which as he says is a through hole unlike all the other dimples. For the first few seconds of the video this hole seems to have a 'blank' under it, grey, same colour as the main body. As it approaches half way this suddenly changes to a distinct line across the middle ( it's in a different orientation to the line notepad underneath ) it seems quite clear and definate i.e. not a scratch. A bit longer on it suddenly goes black ( quite sharp - i.e. its not a shadow ), then returns to the ' line ' then to the grey ' blank '.

So my thoughts are that there are markings on the back plate that are positioned to show as described when there are specific conjunctions between the outer dial and inner one. Like for example the ' line ' is a prior warning indicator during rotations ( nearly there.... ) and the black indication = spot on! Just a wild guess though!

Unfortunately without knowing the logical behind the rotations the guy is doing it's impossible to relate these events to positions of the dials very easily in such a short time. However, I just thought my observations might be of interest.

regards Mike

Suddenly thought I could probably do screen grabs to illustrate all my earlier waffling!

... and they appear to do so when the 30 & the 0 are in alignment.

Also he detent spring would appear enabled to engage, or lock, both dials at the point of alignment.

It's not clear (to me) if this applies to both 0 points on the outer dial.

Quoting from the original reddit posting "Both rings rotate clockwise freely but lock in this position when rotated counterclockwise." (see Reference earlier in thread)

"...this position..." is a bit ambiguous but I am assuming that it is the home position of the apparatus i.e. 30-0-0

FC

I thought perhaps the line observed through the hole at 30 might be caused by a pin inserted and scratching the surface before it drops into the corresponding hole below.

I feel there must be something missing, even if only a pin. The single hole close to the centre of the inner disc must also have a purpose, possibly associated with whatever is missing.

All three scales must be read in combination somehow.

P.S. The clockwise only rotation suggests some kind of progressive calculation rather than a simple conversion.

Mike.

Edited By Farmboy on 17/01/2022 15:34:09

They certainly look like it, but I am still a bit sceptical - how many other circular slide rules of any function have this type of design? It's quite a lot of effort to go to to stamp and deburr twenty holes on a disc that could have been flat and turned with a finger. Rotary telephone dials required a positive stop and a bit of effort to turn, so the through hole design made sense.

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True, but : We don’t know the purpose, or the original price, of the device …

In some markets, a dash of “perceived value” can work wonders

MichaelG.

Anyone who, like me, hasn't already done so might like to scroll through the comments below the Reddit post where the owner of the device has added a few more details about its operation.

Mike.