# Pythagorean cup

(Redirected from Pythagoras cup)

Cross section

Cross section of a Pythagorean cup.
Pythagorean cup (also known as a Pythagoras cup, a Greedy Cup or a Tantalus cup) is a form ofdrinking cup which forces its user to imbibe only in moderation. Credited to Pythagoras of Samos, it allows the user to fill the cup with wine up to a certain level. If the user fills the cup only up to that level he may enjoy his drink in peace. If he exhibits gluttony, however, the cup spills its entire contents out the bottom (the intention being: onto the lap of the immodest drinker).

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## Form and function

A Pythagorean cup looks like a normal drinking cup, except that the bowl has a central column in it – giving it a shape like a Bundt pan in the center of the cup. The central column of the bowl is positioned directly over the stem of the cup and over the hole at the bottom of the stem. A small, open pipe runs from this hole almost to the top of the central column, where there is an open chamber. The chamber is connected by a second pipe to the bottom of the central column, where a hole in the column exposes the pipe to (the contents of) the bowl of the cup.
When the cup is filled, liquid rises through the second pipe up to the chamber at the top of the central column, following Pascal's principle of communicating vessels. As long as the level of the liquid does not rise beyond the level of the chamber, the cup functions as normal. If the level rises further however, the liquid spills through the chamber into the first pipe and out the bottom. Hydrostatic pressure then creates a siphonthrough the central column causing the entire contents of the cup to be emptied through the hole at the bottom of the stem. Modern toilets operate on the same principle: when the water level in the bowl rises high enough, a siphon is created, flushing the toilet.

## Common occurrences

A Pythagorean cup sold inCrete

A Pythagorean cup sold in Samos
The Pythagorean cup is credited as an invention to Pythagoras. For this reason, it is sold often on the Greek island of Samos as a touristsouvenir, sometimes with accompanying information, such as: "Tradition says Pythagoras, during water supply works in Samos around 530 BC moderated the workers' wine drinking by inventing the 'fair cup'. When the wine surpasses the line, the cup totally empties, so the greedy one is punished." Whether there is any basis to this historical assertion is unknown. However, water supply was evidently a problem in Pythagoras' time in Samos, as demonstrated by the 1,036 m (3,399 ft) Tunnel of Eupalinos that the ruler Polycrates had dug through rock to serve as an aqueductbringing water to the city.
Hero of Alexandria (c. 10–70 AD) used Pythagorean cups as hydraulic components in his robotic systems.
It is also sold in some toy stores as a practical joke gift.

## Wednesday, 20 June 2012

I have been neglectful of this blog and that is in part because I have been so distracted by the huge world of the Internet, I have been exploring Tumbler, Pinterest, Stumble upon,  blogs and facebook groups.  Are you aware of the wealth of information on Facebook pages such as Glaze and Recipe Sharing?  Anyone with a facebook account can join and read the endless conversation threads, find answers to all sorts of glazing questions and share their own knowledge.  Recently this group ran an online glaze course.  It was quite fascinating.

This is an enjoyable blog to wander through, the blogger is Canadian ceramicist Carole Epp.

And here are a couple of other good blogs to send you on your way:

http://acupaweek.blogspot.co.nz/

http://www.ceramicart.com.au/index.shtml

http://www.archiebray.org/

For those wondering what Tumbler is, here is one with a cute name:

http://nicecupbro.tumblr.com/page/20

Don't forget to check in on Auckland Studio Potters facebook page as well.

### Domesticware exhibition 2012

Friday 22nd June is the opening of ASP's first Domesticware exhibition to be held off the ASP premises.  We have hired the foyer of the Mt Eden Village Centre for a one week show.   We are curious to see how it will go, Mt Eden seems to be a great location for anything to do with the arts and hope to snare a new audience for contemporary ceramics -  in this case for high quality funcitional work.

The opening event is from 5-7pm and the show runs daily from around 9.30 until 5pm. The exhibition will be staffed by volunteers from the ASP.

Julie Collis is allocating the awards for the work.

Update:  the number of entries has far exceeded expectations and due to space constraints we are trialing having work in Reserve.  As some work will be taken by people on a Cash and Carry basis (unusual for an exhibition but needs must and all that) we will be able to replace some pieces as space becomes available.   We will see how this works.  Hopefully the award winning pieces will be able to remain on display for the duration of the show.

 Signage designed for ASP by Mark Goody

 Earthenware teapot by Suzy Dunser

 Premier Winner: Earthquake proof teapots by Rick Rudd.

 Robot jars by Jo Ann Raill

 David Mason

 Mike Donaldson

 Merit winner  - Salt fired teapot by John Evans

 Merit Winner - Porcelain beakers by Jill Duncalf

 Merit Winner: Vessels by Barbara Skelton

 Todd Douglas

 Sgraffito plates by Helen Perrett
 Tea bowl and coffee mugs by Margaret Sumich
 Teaset by Margaret Bray
 Bowl by Peter Lange
 Bowls by Simon Leong

 Special Merit Award to Annie McIver for this Chicken  teapot Chester Nealie Andrew Van der Putten Salt fired jug by Peter Lange Woodfired shino bowls and platter by Elena Renker Marilyn Wheeler Brendan Adams Salt fired teapots by Chris Southern Porcelain by Kim Rochester Porcelain by Rachel Carter Porcelain by Charade Honey Porcelain by Sophie Lankovsky Soda fired pourers by Duncan Shearer Earthenware bowl by Sarah Guppy Carbon trapped shino plate by Petra Molloy Platter by Bec Plowman Merit Award winner:  John Evans Todd Douglas Salt fired vases and jug by Mark Goody Salt fired set by Yuko Takahashi Selector Julie Collis with Brendan Adams ASP President Peter Lange with selector Julie Collis Peter Collis with Jo Raill Kim Rochester and Rachel Carter Peter Stichbury and Chester Nealie Kirsty Senior and Suzy Dunser Clock by Marcellan Teaset by Theresa Watson .