The most British memory?

This isn’t exactly new (The Register from 2013), but, as it came up elsewhere and is a story both amusing and technical interesting, I might share it here, as well. Namely, it’s about Alan Turing’s proposal to substitute the mercury in EDSAC’s delay lines by gin!
(At least, there wouldn’t have been a breach of etiquette involved in running EDSAC in the morning, I guess.)

The reason behind this was mostly cost (in modern terms: the mercury required to fill the memory tanks of the EDSAC reconstruction would have come at about £160,000), but it would have also made sense from a technical perspective. So, without further spoilers, head over to The Register:


By coincidence I’ve just unearthed a tab which mentions this gin idea of Turing’s, the 1967 Turing award lecture by Maurice V. Wilkes:

Some snippets, unrelated to gin:

two groups of programmers; the first comprised the “primitives,” who believed that, all instructions should be written in octal, hexadecimal, or some similar form, and who had no time for what they called fancy schemes, while the second comprised the “space cadets,” who saw themselves as the pioneers of a new age

Incidentally, I fear that in that automatic programming debate Turing would have been definitely on the side of the primitives. The programming system that he devised for the pioneering computer at Manchester University was bizarre in the extreme. He had a very nimble brain himself and saw no need to make concessions to those less well-endowed

I well remember that once, during a lecture, when he was multiplying some decimal numbers together on the blackboard to illustrate a point about checking a program, we were all unable to follow his working until we realized that he had written the numbers backwards. I do not think that he was being funny, or trying to score off us; it was simply that he could not appreciate that a trivial matter of that kind could affect anybody’s understanding one way or the other.


Interesting. And for me, the second time I have heard mention of mercury being used in an interesting way, the first being on some cars for stability. Idea was that you’d have some network of conduits on the bottom part of the car, half filled with mercury. When you’d abruptly turn your car left for instance, inertia would push the mercury on the right side of the car and it being heavy would stabilize it, or something to that effect.
I think the cost was also the factor that led to this being discarded as a feasible solution on the long run.

I never actually found a reference of that more than two different people that told me about that, so not sure if that’s actually true, though.

we were all unable to follow his working until we realized that he had written the numbers backwards

It actually makes a lot of sense for numbers to be written little-endian, i.e. lowest digit first. I believe we have the system we do because when we imported decimal numbers from Arabic we used their format, but without understanding that they were embedded in a right-to-left language. We should have reversed the order of digits when we copied arabic numerals into Western languages.

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But spoken numbers are big-endian in English: Three thousand, five hundred and seventy four. It is natural to write that down as 3574 so the reader can speak it “on the fly” when going left to right in the text.

Though to be fair, you do have to scan the whole number before you can go back to the 3 and know it is “three thousand” and not “thirty thousand” or “three hundred”.


(In my childhood, it was just about still possible to give a time in little endian order: five and twenty to three, for example.)

Still using roman numerals out here. :slight_smile:
Language changes over time. Who knows someday numbers could be read
in revese order. Big endian vs little endian in English is new for me.
I am just happy that we got ZERO as a nothing number.

Also, see Jane Austen, where protagonists used to be aged three and twenty… :slight_smile:

@oldben D!
Duodecimal makes a lot of sense, since we can count an extra number for a full hand by using a fist for 6 – and two handfulls is 12. It’s actually rather amazing that we should have lost the ability to count two more numbers when using our hands for counting, down the road that is human history. (Which somehow also shows that efficency isn’t always king.)

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Some cultures still count much higher than 12 using body parts. For example, they may start with the fingers on one hand but then move up via elbow and shoulder and then across the body and down the other arm. I seem to recall that in one group the nose counts as 14. And yes, there are some that include the male appendage, making life mathematically difficult for women. I don’t think any of these cultures has yet moved on to calculus.

Are the mercury delay lines in this gin story the very same ones that involved originally sending the mercury back to the manufacturer to be washed of contaminants? That story reminds me of how different things were back-in-the-day w.r.t. repair versus replace. After rabbits chewed through my EV charge cable, the car dealership said I had to buy a whole new charger for $1,000. They couldn’t simply fix the cable. Alas, I capitulated, but bought a used one on eBay for $136.

Or you can just say “three five seven four” which covers most use-cases. And today we’ve managed to create an email addressing system which demands much the same, “emm aye you are why…”