# Ancient/Classical Cube Root Mechanism

**URL:** <https://boards.straightdope.com/t/ancient-classical-cube-root-mechanism/752697>\
**Category:** Factual Questions\
**Created:** [April 20, 2016, 1:46am UTC](https://boards.straightdope.com/t/ancient-classical-cube-root-mechanism/752697 "2016-04-20T01:46:22Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Trinopus](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Trinopus](https://boards.straightdope.com/u/Trinopus)\
**Post date:** [April 20, 2016, 1:46am UTC](https://boards.straightdope.com/t/ancient-classical-cube-root-mechanism/752697/1 "2016-04-20T01:46:22Z")

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A friend of mine, whom ordinarily I trust, has said that the Ancient Greeks had a device, something with sliding rods on hinges, that let them calculate cube roots.

(Not the Antikythera mechanism, apparently.)

The trouble is that he can’t give me a good reference to it, and I’ve Googled madly and failed to find anything. (I am, alas, a Google dunce.)

Does anyone have any idea what this mechanism might be?

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**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\
**Post date:** [April 20, 2016, 2:02am UTC](https://boards.straightdope.com/t/ancient-classical-cube-root-mechanism/752697/2 "2016-04-20T02:02:29Z")

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Could it be the tomahawk that allowed them to trisect angles?

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**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\
**Post date:** [April 20, 2016, 2:41am UTC](https://boards.straightdope.com/t/ancient-classical-cube-root-mechanism/752697/3 "2016-04-20T02:41:21Z")

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About 3/4 of the way down [this page](http://www.hellenicaworld.com/Greece/Technology/en/Catapults.html) is a diagram of a

> [@](#):
>
> Cube Root extractor, a simple mechanical contrivance invented by an unknown Greek geometer in the third or fourth century B.C., [which] made it possible to design a stone-throwing catapult to scale by solving a formula stating in effect that the diameter of the cord bundle in dactyls was equal to 1.1 times the cube-root of 100 times the weight of the stone in minas. In order to find the cube-root of some value W, for example, one …

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<div class="post-metadata">

**Author:** ![Trinopus](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Trinopus](https://boards.straightdope.com/u/Trinopus)\
**Post date:** [April 20, 2016, 3:19am UTC](https://boards.straightdope.com/t/ancient-classical-cube-root-mechanism/752697/4 "2016-04-20T03:19:19Z")

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> [@Saint\_Cad](#):
>
> Could it be the tomahawk that allowed them to trisect angles?

Ooh, I know that one! I think Martin Gardner put it in one of his “Mathematical Games” columns!

> [@septimus](#):
>
> About 3/4 of the way down [this page](http://www.hellenicaworld.com/Greece/Technology/en/Catapults.html) is a diagram of a

Sooper-dooper! That’s it! And it’s amazingly simple! I’m impressed as all dickens!

Thank you!