The Clock Trick Principle

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Bob Farmer
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The Clock Trick Principle

Postby Bob Farmer » January 31st, 2025, 8:23 am

I am trying to trace the origins of the Clock trick/principle.

Jon Racherbaumer has traced it back to at least 1912 in his manuscripts on the effect, (Chronopoly, 1992, Clockwork 2.0, 2002).

Stephen Minch notes that Bill Kalush found a non-card trick that uses the same mathematical principle in Nicolas Chuquet's Triparty, an exceedingly rare work written in 1484. It became one of the repeated staples in works on conjuring in the 1700s and 1800s, and probably earlier (so it’s revolutionary in the sense that it goes back to at least the American revolutionary war).

In the write-up for “Crazy Clocks,” by Fred G. Taylor, Pallbearers Review, p. 150, January, 1968, Fred notes that, “… this is an old German effect,” Fred doesn’t mention which old German he was referring to, but perhaps he didn’t mean it that way. A much younger German, Denis Behr, lists the effect at his Conjuring Archive:
https://www.conjuringarchive.com/list/category/799

Philippe Billot
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Re: The Clock Trick Principle

Postby Philippe Billot » February 1st, 2025, 4:22 am

"Le jeu du cercle" (problem no. CLVII) explained by Nicolas Chuquet° is made with coins and he wrote that you can do it also with the days or the monthes.

In 1612, Gaspard Bachelet in his book Problèmes plaisants et délectables qui se font par les nombres expliained this divination with numbers which form a cadran. There are only ten numbers and he explained that you can do it with cards.

In 1829, in Nouveau Manuel complet des sorciers (anonymous), the trick is presented under the title : "Déterminer sur un cadran l'heure à laquelle une personne a secrètement choisi de se lever." which gives a pretext to present this trick

Philippe Billot
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Re: The Clock Trick Principle

Postby Philippe Billot » February 1st, 2025, 7:42 am

It seems it was Hercat in Card Tricks and Conjuring Up To date (1895) who was the first to describe the trick in english

Bob Farmer
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Re: The Clock Trick Principle

Postby Bob Farmer » February 1st, 2025, 8:29 am

Philippe: Wonderful! Thank you so much. Will send along something related to all this in a few days.

EdwinCorrie
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Re: The Clock Trick Principle

Postby EdwinCorrie » February 2nd, 2025, 6:42 am

I'm no mathematician so you'll probably know better than me, but is this related to the Josephus Problem? If so, it's in Luca Pacioli (ca. 1500) (https://repositorio.ulisboa.pt/bitstrea ... _Hirth.pdf page 46). According to David Singmaster it goes back to at least the 9th century.

How does Philippe find all this stuff? Out of curiosity I tried checking some of his references. Maybe I'm looking at the wrong thing, but Bachet (Problem XXII) seems to be describing the ancient "divining which person took which of three/four objects" trick with coins laid out in a circle.

Judging by the title, the trick in "Nouveau manuel complet des sorciers" seems to be the same as the one in "Die Zauberwelt" (second on the list in Denis' archive). See under "Le cadran" on page 150 and the plates between pages 406 and 407 (very small, but showing a clock dial with playing card symbols).

The other reference in Denis' archive (from Conradi) is definitely a sort of clock trick, though you have to count round the circle to the 37th card to find the selection.

Philippe Billot
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Re: The Clock Trick Principle

Postby Philippe Billot » February 2nd, 2025, 6:53 am

Hello Edwin,

Regarding Bachelet, in the edition of 1612, le trick is explained page 95 (probleme XVIII). My reference is for another edition. Sorry

Bob Farmer
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Re: The Clock Trick Principle

Postby Bob Farmer » February 2nd, 2025, 8:11 am

Excellent notes, once again and thank you.

EdwinCorrie
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Joined: August 18th, 2019, 4:56 pm

Re: The Clock Trick Principle

Postby EdwinCorrie » February 2nd, 2025, 10:35 am

Hello Edwin,

Regarding Bachelet, in the edition of 1612, le trick is explained page 95 (probleme XVIII). My reference is for another edition. Sorry
Bonjour Philippe! Sorry, my mistake. It's the right edition, but I was looking in the wrong place.


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