That Strange Calculator Again

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Very sad, isn’t it !?!

Reverting to first principles … Has anyone worked-out why the maker felt it necessary to include the tabulation of the obvious [sixteen times table] at the bottom-right corner ?

MichaelG.

Edited By Michael Gilligan on 14/01/2022 12:28:42

Just had another go at trying to analyse this logically, disregarding all other suggestions:

Observations:

Inner disc indentations numbered 1 to 30
Outer "telephone dial" ring numbered 0 to 9 : 0 to 9
Fixed scale numbered 0 to 18

Speculation:

A possible use would appear to be to rotate the inner disc to select a number between 1 and 30, lock this with the sprung detent pin, then rotate the outer ring to select a number between 0 and 9. From this point one would presumably select a number on the fixed scale and read the appropriate 'fractions'.

I can't work out why there are two sets of numbers on the outer ring but 0-9 suggests they might follow a decimal point. However this does not seem to fit well with the 0-18 on the fixed scale.

I still have no idea of the original purpose. Perhaps the next step would be to make a copy of the device and create a table of results using the above method. Has anybody tried this?

Mike.

Hi, I have also noticed the 0-9 twice on the outer ring and wonder if they represent the tabulations at the bottom right, which only go up to 9 and 0 representing, well! I guess most people would take it as 0. The other thing I'm curious about is what look to be holes that I've arrowed in blue, green, red and yellow, the blue and green one alternate all the way round, maybe windowed cards or something like pointers, are pegged into them to give the answer to whatever this gadget may solve.

Regards Nick.

I think most of the little black dots are rivets. 24 around the outside, a circular pattern of 10 around the outside of the circular parts. Can't tell if the others are holes or rivets but I suspect there is one underneath the latch that makes a pattern of 4 on the outer ring.

It may be something to do with coal deliveries. In my youth the coalman came round with a lot of loose coal and a lot of sacks. Most sacks were already filled with 1cwt but if you wanted a smaller amount it would be weighed out on a balance scale. If the coal was paid for by the ton this could help with costs and also this may be something to help work out which weights should be used on the balance scale to get fractions of a cwt in a sack with a minimum number of weights.

Martin C

Oooh, I've only just spotted that, Nick, now you have pointed it out!

The wear makes the graduations hard to read and I'd rather assumed its numbers all go up to the number of holes as the outer and centre scales do.

Looking more closely, it gives three figures-0 on the intermediate ring, with its 9 and 4.5 points drilled for... what? Locking-pins? A moveable pin that makes the circle the pinion of a 1-to-number gear? Arithmetic to the base-9, or base-10?

The thing does not look thick enough to hold much internal mechanism but it must have at least a base-plate; and there might be enough depth for simple gears formed in the undersided of the visible parts, or stamped from sheet-metal.

The inner of the two "blue" holes between the printed 4 & 5, 14 & 15, one or two others, and peeping out from under the spring, look more like small rivets than holes - either holding it all together or "gear teeth" . So does the right-hand "yellow" hole. All leading to Farmboy's ideas.

If this is so it does make more sense of the direction-instruction arrows and the detent.

Someone went to a lot of trouble to design this device, and someone else used it regularly. I reckon the Antikythera Mechanism less abstruse!

"Copyright" or "patent" ? The mechanism as such could not really be patented because the concept of bar-type, cylindrical and circular, special-purpose, slide-rules, and cypher-key setters, was already well-established by 1908. Copyrighting the printed matter was probably the only way to ensure other makes were not available.

Anyway, I am following the lead hinted at above, of it perhaps being a pharmacological instrument.

Hi Nigel, well if the red and yellow ones are holding gears or maybe little dogs to prevent it being turned anti-clockwise, it would make sense of their random looking positions and the blue and green ones that Martin suggests make logical sense. Not always easy to see depth when it's just a flat picture. Thanks for your replies.

Regards Nick.

There's a better picture and a video at the LINK that MichaelG posted last year.

The small dots on the surround that Nick has arrowed in blue are said to be pins holding it down to the wooden base.

The two spots near the numbers 9 on the ring appear to be slotted screw heads but I can't work out their purpose.

There doesn't seem to be any complicated mechanism involved other than what is visible.

This is just further observation and speculation

EDIT:

Further observation: In the ring of dimples on the centre disc the one at position 30 is a through hole which lines up with either a hole or mark at both postions 0 on the dial ring.

Mike.

Edited By Farmboy on 14/01/2022 17:40:35

The only moving part appears to be the inner disc ie it rotates clockwise?

The ring with the 20 large holes next to the inner disc shows a grey bottom to those holes. I wonder if that grey bottom material is attached directly to the inner disc ie it rotates with it. Were there, at one time, symbols on the grey holes?

The centres of the grey holes seem lightly worn.

The grey holes next to 8 and 9 seem to be slightly dished (under high magnification)...could there have been a circular insert in there?

All the fraction denominators divide in to 240, the number of pennies in an old Pound.

The small table at the bottom right could be Lbs and Ounces.

I still have no idea what device this is though. ;-(

Ches

Edit: The dishing appearance is possibly just a shadow.

Edited By Ches Green UK on 14/01/2022 18:18:15

Edited By Ches Green UK on 14/01/2022 18:20:06

My guess is that the larger of the holes, in the internediate ring, are to take a finger or, say, the end of pencil - as in the old telephone dials. That would account for light wear.

The holes in the central disc are for the detent, and by its shape I think it was meant to function as a rather crude ratchet.

Not sure what that curious wire loop in the middle does. It could be a friction device to give a more positive motion.

I don't think the wooden base in the photo here is its own but is a table - the image on Reddit shows more of that, with one or two other objects.

A pity it no longer bears its maker's name - that could have been useful. It might have been on some part long lost, of course, but I'd have thought it would have been with the rest of the printing.

I've been really intrigued by this and have looked for relationships between 18, 9 and 30, following on from the analytical observations of Farmboy... and peoples wondering whether it's for adding or dividing things...

"Inner disc indentations numbered 1 to 30
Outer "telephone dial" ring numbered 0 to 9 : 0 to 9
Fixed scale numbered 0 to 18 "

No idea if there is any relevance in this but maybe it will give someone smarter a hint?

There are 18 inches in a cubit, 9 inches in a span, also 3 palms in a span, 3 inches in a palm)

does this help perhaps?

Despite what the video shows, the design of the "ratchet" to me indicates that the inside disc should rotate anticlockwise. There is a pin that would stop the spring moving downwards if the disc is rotated clockwise.

The fractions are interesting, in some sections they are all the same, just exxpressed differently, 1/2, 4/8, 3/6, 6/12.

Peter

I've just had a look at the video - sorry, did things in rather the wrong order there.

I don't know if the video had any sound. It didn't at this end.

It would seem that the detent might be set manually then. Lift it and rotating the dial pulls the disc round but that's probably just by friction. What was obvious is at least one hole in one of the two rotated parts, visible in certain positions, presumably allowing the dial and disc to be locked together by a removeable pin, but he was turning the thing continually and a bit rapidly for me to see any pattern.

'

The problem I can see with trying to analyse it by, perhaps, a speadsheet or yet a working copy, is the sheer number of possible combinations and not knowing exactly what locking-pin holes do exist and where. Nor how to use it.

If it were not for that pesky arithmetic I'd be inclined to think this is a simple encypherment device, well before Arthur Scherbius' 1918 invention of what became the 'Egnima' system*.

This because the Science Museum search revealed a very simple device looking like this one, and older, but purely by letters, e.g "a" becomes "f" , etc. Very easy to crack from simple word-analysis if it merely slides one intact aphabet several letters past another. Far harder if the equivalent alphabet is scrambled, and even harder still by changing to a different equivalent, denoted only by a need-to-know cypher-key number, at intervals.

I do not know though, how advanced codes and cyphers were in Edwardian times.

So that is only a wild guess and I am still inclined to think it was some trade-calculator.

'

'

*{Enigma's principle, described here very sketchily, uses multiple scrambling. It was an electro-mechanical machine holding a line of rotors. Each rotor swapped each letter of the alphabet for another by fixed but random internal wires between an input and output contact, then pitched the output against a third letter on the next rotor, which changed it to a 4th... and that's just 2 rotors.

So let's say we type A into Rotor 1 whose A input contact goes to output R; then that meets input Z on Rotor 2 which obligingly turns it to D.... . Very secure but we can do even better. Let's call our cypher key RD, by outputs.

On some pre-determined date later, turn Rotor 2 against Rotor 1, so A still becomes R, but now meets B on R2 and becomes G.... Our new cypher key is RG - issued beforehand in a code-book which of course does not reveal the rotors' wiring.

Put 4 rotors together and breaking the cypher becomes formidably difficult because it is a gigantic mass of permutations changed at frequent intervals to a different rotor set, or the same re-ordered along their shaft. Cracking the Enigma codes was very much a matter of captured rotors and cypher-books, as much as the machine.]

I'm a long way from understanding this device but I do wonder whether it might have had some pins or similar that went into the small holes of the inner disc and circle and registered them in set positions for some setting purpose.
I'm intrigued by the number sets that are evident on the device, 12,16,20,48. all of which had monetary associations back in the day and additionally were associated with the avoirdupois weight system, ozs, lbs cwts. tons.
I recall the time when banks had scales to weigh your little blue bag of copper or silver coins and that one old penny weighed a third of an ounce so 48 weighed a pound and a pounds worth of pennies weighed five pound!
I am further intrigued by the fractions in the outer segments particularly the ones with an addition appended.
If you change the + sign to - and count the addendum as 1/48th ( 0.020833) in every case the resulting sum then equals the simple fractions in the same segment.

Segment 6 3/8 2/5 -6(0.020833) = 0.375

5/12 -2(0.020833) = 0.375

Has this got any significance?

Bob D

More observations ( I really need to stop this and get to bed )

I think there may be a disc under the visible ones, with the dial ring attached to it by the two screws at positions 9 and perhaps by what appear to be rivets at 4.5. The whole disc pivots on the central screw and the inner disc is free to turn independantly. The small wire loop on the centre screw does look like a friction device, possibly to ensure the inner disc turns with the outer until it is locked by the detent. The signs of wear under the loop show it is in close contact with the disc.

I'm beginning to think it might be a one-off or prototype. There is sufficient, if slight, variation in the numbers to suggest they were hand drawn by a good draughtsman.

There must be some significance in the arrows indicating clockwise rotation. I wonder if it suggests some sort of progressive calculation. For just a simple static calculation it wouldn't seem to matter which way it is turned.

Mike.

I've just looked back at Grindstone Cowboys earlier link to reddit. Trawling down to KarenEiffel's response led me to an illustrated book of Rechnenmaschinen. Look a bit familiar?

Bob D

I havn't a clue to it's use or how it works but where the fractions have +1 to 9 attached does one take the number and using the lower table add the corresponding number to the fraction.If this is correct it would be a guess.

Frank

May not help but Adall based in Birmingham produced/sold Concentric Disc adding machines. a special purpose version which is used for a particular trade or unit of measure? There are parts missing as has already been established.

Robert Butler

I agree the 1=16 to 9=144 is to do with the two 0 to 9 scales on the telephone dial.

The big picture is revealing:

Clicking on the big photo above to expand it shows:

• All the 'holes' on the outer tableau are rivets. (Nick's green and blue arrows point to examples)
• The four opposing objects on the dial are, or were, small screw-heads. (Nick's red arrows)
• One of Nick's yellow arrows is a through hole, the other is a rivet.
• 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.
• I don't think it's home-made or a prototype. The number stamping looks professional and the metal under the dial holes seem to show signs of wear. It's been used, and I think is Nickel plated.

Too simple to be a general purpose calculating ring and the 'fractions' are weird. Unlikely to be a cypher device because it's base 16/144, not 26/36.

The two 0-9 scales may indicate modulo arithmetic (which is like a cypher disc), but the 0-19 scale suggest ratios 4:5 and 2:3, maybe 8:15.

None of this helps - still bewildered.

Dave

Worth a click on this site to see it in operation.

Note the right thumb on the black bar to stop the inner ring rotating until required

https://imgur.com/a/Nfe12p0

Bob D

Next stop should be The Arithmeum,. Bonn University. It has a museum of mechanical calculators, lots of them are circular and there are 10000 exhibits to check out. Some of the detail is in German so you may need some translation before calculation.

https://www.arithmeum.uni-bonn.de/en/arithmeum.html,

Bob D