Then you don't want Acme's Cup of Tantalus.. ..These are self-siphoning cups that can't be filled.

As you pour water into an Acme Cup of Tantlus, everything works fine ... for a while. The cup fills with water. But after it reaches a critical depth, suddenly the water drains out through the siphon. (In Canada, Australia, and Britain, the water drains through a syphon).

The Acme Tantalus Wine Glass

Cup of Tantalus (Wine Glass of Tantalus)  by Acme Klein Bottle

Our Wine Cup of Tantalus is a syphon glass. A question mark shaped tube extends up from the bottom. Both ends of this tube are open.

When you first begin to pour water into the wine glass, it fills normally. But watch - when the water level reaches the top of the question mark, the siphon starts flowing the bottom. The siphon keeps flowing until all the water runs out the bottom.

Our Tantalus Wine Glass is also called a Justice Cup, the Greedy Cup, Pythagorean cup, or a cup of Pythagorus.

This type of siphon also occurs in nature - for example at the "cold water geyser" at Afton, Wyoming. Every 18 minutes, the spring flows while the siphon is active. Then it waits for 20 minutes while the reservoir recharges.

Diagram of Cup of Tantalus

Two images from the 1878 book, "Elements of Natural Philosophy" by Elroy Avery. On the left, this served as my model when making Acme's Wine Cup of Tantalus.

To the right, a cold water siphon spring.

The Acme Tantlus Drinking Mug,

We also make a Tantalus Drinking Mug - where we hide the siphon within the handle of the stein ... unless you're clever, you won't figure it out.

Drinking Mug Cup of Tantalus by Acme Klein Bottle

Cup of Tantalus, Syphon not running

Drinking Mug of Tantalus

By adjusting the fill rate from your faucet,, you can make a Tantalus Cup into into an intermittant siphon ... it fill for 30 seconds, then empty, then refill and empty. It's a fluid dynamics oscillator!

Don't confuse these with cheap dribble-glasses. Nope, these are expensive dribble glasses, made from genuine borosilicate glass with *real* silicon atoms.

So who was Tantalus? As son of Zeus and the nymph Plouto, he lived in the deepest portion of the Underworld. ... He had stolen nectar and ambrosia from Zeus's table and given them to his people. The gods punished Tantalus by putting him in a pool of water, benaeath a fruit tree with low branches. Whenever he reached for the fruit, the branches raised and the fruit was just beyond his grasp. When he bent down to drink, the water receded before he could get any. Ever thirsty, ever hungry, Tantalus never ate dinner. Much like my children, unless you order one of these.


The Acme Mystery Pyramid Teapot:

The Topless Teapot!

There's a built in funnel-tube on the bottom. Turn it over to fill, then quickly set it upright. If you fill it less than halfway, water won't spill out.

This is known amongst Puzzle People as "Cadogan Teapot", popularized by Lord and Lady Cadogan of England around 1820. These teapots were said to be "Non-spill" teapots for use on the railway, but this is pretty doubtful. For examples of opaque ceramic topless teapots, see the Puzzle Museum.

I make each Lady Cadogan's Teapot from Pyrex borosilicate glass, so it's heat resistant. You can put it on a gas stove and boil water in it.

Now back in stock - just made a few more!

Cadogan Teapot (Glass Pyramid Teapot) Topless

Pyramid Teapot pouring into a Cup of Tantalus

Siphon or syphon? I dunno. I'll use 'em both. Go to Acme Klein Bottle's Home Page

I last updated this page on 2021 July 11