KRAZY KINETIC KONTRAPTIONS. Disks sway, plates spin, rods shimmy, levers flip - bells and gongs sound, xylophone bars play, wooden rods clatter. Rhoads's intricate kinetic sculpture enchants people in public spaces

When George Rhoads was a little boy, he took clocks apart to see how they worked. By 10, he was making calendar clocks of his own out of wood, pennies, and soldered bits of metal sheeting.

Fifty years later, he's still playing around with mechanical devices - but now the fun of it goes beyond just pleasing himself. Mr. Rhoads's audiokinetic sculptures delight crowds in shopping malls, bus terminals, airports, and museums in the United States and Canada.

``Archimedean Excogitation,'' on display in the lobby of Boston's Museum of Science (see next page), is typical of Rhoads's artistic ``machines'' that turn work into play.

It's a huge metal contraption 25 feet high, eight feet square at the base. Inside a supporting frame, there is a frenzy of activity triggered by billiard balls rolling simultaneously down nine different mazes of track. As the balls move through spirals, loop-the-loops, and free-fall, each bumps up against dozens of mechanical devices and percussion instruments.

Sections of track tilt, disks sway, plates spin, rods shimmy, levers flip. Here and there, bells ring, gongs sound, xylophone bars play, wooden rods clatter. Like all of Rhoads's so-called ball machines, it's a noisy, unpredictable affair that observers find hard to walk away from.

``When you watch people passing through the lobby, they stop and stare in amazement,'' says Larry Bell, associate director and head of the exhibits division of the Boston Museum of Science.

According to Mr. Bell, Rhoads's sculpture manifests the museum's goal of presenting the principles of physics in an educationally engaging way.

``We've found that people will watch `Archimedean Excogitation' for much longer than they do exhibits of the very same mechanical devices - gears, levers, pullies, and the like - that are displayed elsewhere in the museum in a more didactic fashion,'' Bell says.

It's not only Science Museum-goers who are drawn in by Rhoads's quirky, imaginative machines.

Travelers passing through Boston's Logan Airport, New York's La Guardia Airport, and the Port Authority of New York and New Jersey bus terminal in Manhattan - as well as shoppers in 10 malls and shopping centers in the US and Canada - find that their cares momentarily disappear when Rhoads's mechanical magic takes over.

``It totally blocks out the rest of the world while you are watching it,'' exclaimed a woman in surprise as she looked at her watch.

The captivating effect that keeps viewers watching is caused by ``distributors'' situated at key points near the top of the sculpture. Often a spinning mechanism or a lever, the distributor can send any ball down two or more tracks.

There is no way to predict which direction the ball will go. You just have to wait and see. The timing is so intricate that it can take up to an hour before an exact sequence of sound and motion is repeated.

Serious Rhoads fans have been known to wait it out.

A particular type of distributor called a ``dumper,'' as well as the motorized hoist that ferries the balls up for another roller-coaster descent, also controls pace - another source of variety that keeps viewers guessing.

``It's all planned out with the dumpers - portions of track on a pivot,'' says Rhoads. ``When a certain number of balls collect in it, the dumper tilts, and they all roll out rapidly, causing an unexpected crescendo of sound and action. When this tapers off, nothing happens for a while, then a small crescendo, a pause, a bigger one, and so on.''

Rhoads's choice of the word ``crescendo'' is no accident. This visual artist says he really wanted to be a composer, but lacked the ability.

During his career of more than 40 years, Rhoads has variously been successful as a painter of expressionistic urban landscapes, an authority on the Japanese art of paper folding called origami, an accomplished medical illustrator, muralist, printmaker, and ceramicist - as well as house painter and furniture mover, when pressed by financial necessity.

In the '50s, Rhoads taught himself to do welding, a skill that would eventually bring an end to periods of living hand to mouth.

``I started with fountains,'' he says. ``These led to a lot of ideas with mechanical things, because you're using the same principles and a lot of the same techniques.''

The first ball machines were single-track, hand-powered devices, small enough to sit on the average coffee table in someone's living room.

These simple, creative devices unite a mind fascinated by, and capable of comprehending, complex mechanisms - with a childlike creativity that takes joy in creating truly fantastic ``toys.''