IMAGINE 19th-century couples in China, Europe, and the United States all playing the same practical joke on their dinner guests: presenting them a jug with many holes in the top through which liquid will pour out unless the pourer knows the secret. Such containers were called puzzle vessels, and there is a whole shelf of them in a traveling exhibition called ``Puzzles Old and New: Head Crackers, Patience Provers, and Other Tactile Teasers,'' which opened Tuesday at the Massachusetts Institute of Technology Museum.
The concepts behind the puzzle vessels date back to Cypro-Phoenician days and illustrate principles of fluid dynamics. Not to mention the timeless and universal fascination with playing practical jokes. The idea that physics and mathematics can be intriguing, perplexing, beautiful, and funny is the motor that has propelled this exhibition through audiences in Los Angeles and New York.
The exhibition features 825 examples of jigsaw puzzles, puzzle locks, plastic keychain puzzles, wooden interlocking puzzles, puzzles you put together, puzzles you take apart, and puzzles you just ... well puzzle over. There's a tangram sectional table that can be put together in hundreds of ways, puzzle rings from Turkey, lovely carved secret-opening boxes from Japan with springs hidden in the grain of the wood, and Puzzle Parties, developed for American families in the 1920s, that contained 22 wire puzzles.
But it's the Coke bottle with an arrow going through it that'll really stump you. Two pieces: a bottle with two holes drilled through it and a piece of wood carved in the shape of an arrow sticking right through the middle. No glue. ``It's a problem of material science,'' says Warren Seamans, director of the MIT Museum, enigmatically. And that's all he'll say about it.
The desire to pit one's intelligence, manual dexterity, and sense of spatial relations against a seemingly impossible puzzle is not new: It is said that Alexander the Great, frustrated at his inability to untie the Gordian knot, finally slashed through it with his sword. But puzzles didn't really come into widespread popularity until the Industrial Revolution, with the manufacturing of steel and radical changes in people's perception of the universe. None of the puzzles in this exhibition are more than 200 years old.
In pre-Columbian America, dexterity puzzles were used to teach hand-and-eye coordination and hunting skills to children. Early jigsaw puzzles, first made in 1760, were maps glued to wood, designed to teach geography. Maria Montessori used puzzles in her schools to help students learn about trial and error. Erno Rubik invented his famous cube to give his architecture students experience with three-dimensional objects.
Some puzzles had political overtones: The innocuous-looking Niagara Puzzle - concealing a file, a tiny compass, and a map - was sent to American prisoners of war in Germany during World War I.
Why are people fascinated by pushing around little black and white numbers in a plastic case? Various reasons, says Sharon K. Emanuelli, who was curator of the exhibition when it was in Los Angeles and Yonkers, N.Y., and is trouble-shooting here in Cambridge. ``It's a way to use your time. It involves your brain, it involves your hands. The more you do, the more you're able to do. You start to learn all the possibilities for how something might be solved. It's training you for problem-solving on all kinds of levels. There are many, many important scientific discoveries and whole fields of mathematical ideas started by somebody who was analyzing a puzzle. Like topology, the study of curving surfaces.''
The exhibition also explores the fad aspect of puzzles. One whole case is devoted to Rubik's cube and its derivations, which swept the world in 1976 but is no longer the rage. Pigs in Clover, a rolling ball puzzle, was a similar fad in 1899. Introduced one week, the next week it was all over the United States; a few weeks later, Europe. ``But in six months it had gone totally out of fashion, as fast as anything we do today with marketing,'' says Ms. Emanuelli.
Most puzzles in the exhibit are too fragile to handle and are placed under glass. But the curators, realizing that visitors would be itching to try one, have arranged nine interactive puzzles ranging from one in which you move pieces around until a dinosaur is caged, to untangling oversize twisted nails hanging on chains.
The exhibition was the brainchild of Gerald K. Slocum, an engineering executive and a die-hard puzzle enthusiast. Most of the items are from his 10,000-puzzle collection, and he was in charge of the historical material in the show. Jack Boutermans, who designs and makes puzzles in the Netherlands, was the design curator.
For those who fancy learning how to make their own puzzles, Slocum and Boutermans have written ``Puzzles Old & New: How to Make and Solve Them,'' which is also a catalog for the exhibition.
When the exhibition closes Jan. 3, it will go to the Ontario Science Center in Toronto and to four cities in Japan - a country of great puzzle lovers. ``In Japan, they anticipate 100,000 people a week,'' says Emanuelli. ``They're redesigning the whole exhibit. The cases are very low, and they're having more interactive things. And they feel they'll have to have somebody with a microphone and have people lining up taking their turn.''
The secret to the puzzle vessel: One hole on the jug works as a siphon. Plug up the rest with your fingers.