By William Raspberry, The Washington Post

Encyclopedia Britannica now has a highly advertised free Web site. What an extraordinary thing it is that people around the world suddenly have free access to knowledge that would have been the envy of a university professor earlier in my own lifetime.

But the encyclopedia is just one small illustration of the explosion both in knowledge and in our access to it since Thomas Jefferson's modest book collection formed the nucleus of the Library of Congress. Not only does my own house now contain more books than Jefferson ever owned, but my access to public libraries, bookstores and, of course, the Web, gives my family information resources beyond the imagination of world-class scholars a short time ago.

I've just had a phone call from a friend who tells me that, in preparation for an upcoming trip to Benin, she's downloaded 75 to 100 pages of information, from a score of sites, on that West African country--information on everything from the local currency, political situation and weather to the latest local news and the street address of the American Embassy. "I'm starting to feel almost like I know the place, even though I've never been there," she said. Marco Polo, eat your heart out.

Nor is it just information that is so profusely available. Think of the difficulties confronting a 19th-century music lover. He could, of course, hear local folk artists. But if he had a fondness for, say, Bach or Beethoven, he'd have to hire an orchestra and a place for it to perform--which means he'd have to be wealthy. Today, any teenager with a CD player (or even an FM radio) can hear almost any music of his or her choosing, performed by top musicians, virtually at will. The same youngster could, at a whim, look at tens of thousands of paintings from the National Gallery of Art.

Hurricane-proof houses that pivot on foundations like spinning tops in slow motion. A nuclear-powered car parked beside the family air-yacht. Human hibernation. Programmed dreams. Sky fishing. Robots cheerfully performing all sorts of chores. These are just a sample of the exotic forecasts about how life would be lived by the year 2000.

Well, 2000's almost here and, as science-fiction author Arthur C. Clarke once wrote, "The future isn't what it used to be."

None of this seemed so far-fetched at the beginning of this century, when the world seemed to be tripping over itself with progress, bursting with new inventions every day. People were learning to drive, listening to radio, talking into telephones, taking vacations.

The Wright brothers made their first successful flight at Kitty Hawk, N.C., in 1903--two years after Wilbur Wright told his brother, Orville, that humans wouldn't fly for 50 years. "Ever since," he said later, "I have distrusted myself and avoided all predictions."

Harper's Weekly might have heeded his advice. "The actual building of roads devoted to motor cars is not for the near future, in spite of many rumors to that effect," it suggested in 1902. By 1925, cars were zipping along New York's Bronx River Parkway--the country's first true highway.

With men flying and zooming along highways, it wasn't such a leap of faith to believe in a technological utopia in which the drudgery of life would be eliminated and the biggest social problem would be what to do with all the leisure time.

Amazing Stories magazine suggested in 1946 that future hedonists could while away the time floating across the landscape in "pleasure bubbles."

The biggest miscalculation, says Brian Horrigan, co-author of Yesterday's Tomorrows, was the notion of a world of infinite luxury and leisure. Today, people feel more hurried and harried than ever. But oh, how rosy the world looked back then.

In 1955, President Eisenhower's special assistant, Harold Stassen, predicted that nuclear power would lead to a world where "hunger is unknown … where food never rots and crops never spoil … a world where no one stokes a furnace or curses the smog, where the air is everywhere as fresh as on a mountain top and the breeze from a factory as sweet as from a rose."

Amid these visions of utopia, it proved harder to predict things that actually shaped the world we live in, said author William Sherden.

The computer. The laser. The telephone. All were more or less accidents, stumbled upon in the course of other research, never predicted in their own right. Sherden points out that as recently as 1950, the dictionary definition of a computer was "a person who computes," a scribe.

The telephone, a group of British experts clucked, "may be appropriate for our American cousins, but not here, because we have an adequate supply of messenger boys." Western Union wasn't impressed either. It declined to buy the patent on Alexander Graham Bell's 1876 invention, saying the public couldn't be trusted to master such complicated equipment.

With 20/20 hindsight, it is easy to mock. But sometimes the seers got it right. In 1902 the writer H G Wells, who started modern futurology, envisaged heavier-than-air flying machines capable of practical use in war "by 1950." Twelve years later he predicted "atomic bombs."

Perhaps the most prolifically accurate forecaster of all was a journalist. In 1900 John Elfreth Watkins consulted "the wisest and most careful men in our greatest institutions of science and learning" before making a series of startling and accurate predictions for the 20th century in the Ladies' home Journal.

The future, Watkins wrote, would usher in air-conditioning, an international telephone service, color photography, frozen dinners, school meals and medicine applied through skin patches. He foresaw a gym in every school, the invention of the snowmobile and the tapping of energy from the wind, sun and ocean waves.

Institutions and individuals alike are coping with a deluge of books, journals, tapes, legal records, documents, electronic mail and torrents of raw data.

The Library of Congress has 113 million items, and every morning 20,000 more pour into the loading dock. Every day, James Billington, the librarian of Congress, worries about issues such as shelving and preservation, but he also worries about broader philosophical matters, such as: Are we truly wiser with all this information?

In 1472 the library at Queens' College in Cambridge, England, had 199 books. At the height of the Renaissance there were people who could claim plausibly to have read every important book ever written.

Today, no one can read everything. The world of knowledge is a vast ocean; the best you can do is occasionally go for a swim.

More than 50,000 books are published every year in America alone. The number of journals published globally is estimated at 400,000. Soon every home will have access to hundreds of television channels. The World Wide Web now has millions of sites.

"It's significant that we call it the Information Age," Mr. Billington said. "We don't talk about the Knowledge Age."

Mr. Billington subscribes to a formula: Raw data can be turned into information, which then, through much added effort and value, can rise to the level of knowledge, which is the foundation for wisdom. But he says that in this era of data overload, we may be going in the wrong direction. "Our society is basically motion without memory," Mr. Billington said. "Which, of course, is one of the clinical definitions of insanity."