They are extremely intelligent and creative -- although they may not have done well in elementary or high school -- and they believe that they were likely born that way, looking into the future, dissatisfied with life as it is.

They are inventors, visionaries who see a need -- or a "want" -- and in attempting to meet it, often develop other devices that improve our lives.

When they are successful, as Ralph Waldo Emerson observed, "the world will make a beaten path to their door." But sometimes that takes a long time.

Their stories and products are featured in The Discovery Channel's 13-part "Inventions" (Tuesdays at 9:30, repeating Wednesdays at 11:30), created with the Smithsonian Institition.

First up is Canadian-born Paul S. Moller, whose computerized flying car has been fondly envisioned by every motorist stuck in traffic. Moller, who works in Davis, Calif., believes that in less than a decade the Moller 200 will be ready for buyers who can afford today's luxury-class vehicles. (He also believes that air space will be computer-plotted in "skyways" so that commuters' flight paths won't cross.)

Moller dreamed of building a flying car when he was growing up in British Columbia. But he was such a poor high school student that he was obliged to attend a trade school instead of a university. (Eventually he earned his Ph.D. at the University of Montreal.)

Spinoffs from his 30 years of work on the flying car include a muffler, which he marketed, and a backpack unit that takes skiers uphill, which he has not marketed because of what he calls "product liability."

Author Gore Vidal turns up in this week's installment to tell host Lucky Severson how, at the age of 10, he flew a flying car called a "flivver" to show how easy it was to pilot a plane. Vidal's father, Eugene Vidal, the nation's first director of air commerce, landed the tiny Pitcairn autogiro on Pennsylvania Avenue.

Also this week is a visit to Silicon Graphics, the computer graphics company that created the undulating water creature for the movie "The Abyss."

Next week, "Invention" features Stanley I. Mason Jr., inventor of so many everyday items that he's hard-pressed to reel off a list. Among them: sticky-tab disposable diapers (the materials of which can be recycled), plastic-underwire brassieres, an improved Band-Aid, microwave cookware, granola bars, the Biopot flowerpot and a dry-ink system of fingerprinting.

Mason's Weston, Conn.-based Simco Inc. develops products for "about 30 Fortune 500 companies," he said. He has a staff of 10 and gives other tasks to some 120 researchers, most at universities.

Mason, whose inventor-father created the electric chair, also teaches MBA students at the University of Connecticut "that someone in the company has to figure out what the company will make."

"I had two goals at the very beginning," said Mason. "One was to invent for myself, and patent and profit -- profit being the result of doing something rather than the goal. The other is to work with clients to develop products for them so the income from that can support my products."

The third installment features K.G. Engelhardt, who specializes in service robotics -- robots that help the disabled and elderly by preparing and serving meals, operating computers and making telephone calls, among other tasks.

"Nobody had ever heard of service robotics 10 years ago," she said, "and so we had to train our own people." She says the field will grow rapidly this decade.

Married at 17 and divorced, Engelhardt worked three waitressing jobs to support her young children and took classes at community colleges. At 36, she enrolled at Stanford University, where the school provided her family with a four-bedroom apartment, and graduated with a 4.0 grade point average. She now heads the Center for Human Service Robotics at Carnegie Mellon University, developing robots for home and health use, and is working on her doctorate.

Engelhardt also is creating models to handle contaminated or hazardous materials for hospitals and airlines.

Last week, before a Discovery Channel reception at the Smithsonian Museum of American History for "Invention," the inventors met together for the first time and talked about what they do.

"I did not start out to look at recycling those products when I was trying to invent voice-controlled robotics for quadriplegics, but the process leads you. In order to solve a problem, we've had to bring in new ideas and inventions," said Engelhardt.

When her dying mother wanted to remain at home, the inventor was able to test her service robots. "I'm planning for what I'll need when I'm 85," she said.

All three agreed that the United States is the most inventive nation in the world, but said American business and industry lags behind in making use of the inventions. The Japanese, they said, are much quicker to see potential and manufacture and market the products.

They also talked about the inventor's role in the production of something new.

"It's not so much a group effort as much as it is a creative person determining what needs to be done," said Mason. "To carry out all the different simultaneous tasks takes a team. Independently, none of those people could do it. They know how to do things, but they don't know what to work on. The first thing is the nomination of a proper goal: How is it possible to do -- -- ? It's very similar to being the conductor of an orchestra, and to being the composer."

As an inventor, Engelhardt said, she finds she also must be a psychologist to coordinate the activities of her staff.

"I think something that is often lost when you talk about inventing and creating is that it is a process. It is not an event in time that occurs. You have the shaping and the molding and the trying and the testing and the redoing and the refinement to get to the main goal.

"Often we're working with people with disabilities and it's important to go to them and ask them what's needed and include them, the end user, in the whole process. Including them is the key.

"I had a goal and that was to help people remain independent, but I also think inventors often have something that rides them."

Moller fits that category: He's a man who was driven by one dream.

"I've got a big emotional element involved here. I had a less professional approach to the whole invention process. I wanted to do some thing; I wanted to achieve this particular objective. I had no realization how complex it was, how interdisciplinary it was going to be, how much money it was going to take."

He estimated that developing his flying car has taken as much as $25 million.

"Other products along the line, synergistic spinoffs, have kept this business going," he said. "I couldn't have gone straight ahead without doing these branches on the side that generated cash flow and inventing other things that I never set out to invent."

Other installments of "Invention" will feature Grateful Dead drummer Mickey Hart, who has found a way to restore America's musical memories; a Japanese inventor with more than 2,350 patents; award-winning inventions by children; Charles Wilz's improved sausage stuffer and Fred Roberts' musical motivational potty training chair.