The Washington law firm Squire Sanders & Dempsey is like many workplaces that find themselves on the front lines of the Fax Revolution.

In search of the latest in communications technology, the firm installed its first fax machine in the mid-'80s. Almost overnight the unit was swamped. So a second, then a third, now a fourth was bought -- one for every 20 lawyers. The machines have a full-time human attendant who does nothing but send (11,000 pages in April) and receive (8,600 pages). "They're constantly going," said Tony Martin, the firm's services coordinator. "All day."

Like all revolutions, this one is moving quickly. Last year about 1.4 million fax (short for facsimile) machines were sold in the United States, doubling their ranks to about 3 million. No longer, it seems, is anyone content to wait for the U.S. mail or the overnight delivery service or even the bicycle courier to deliver that report or purchase order or preliminary sketch. For a generation that has grown accustomed to instant gratification, the fax has been a hit. "What's your fax number" may well be the most common query of working America.

And not just working America. As the machines proliferate -- they are starting to appear in homes and in portable-phone-equipped cars -- new, personal, unforeseen uses are being devised: Dinner party hosts fax maps to guests, friends trade cartoons from the morning paper, young singles respond to the latest offering from the dating service. You can even use a fax to speed your order for pepperoni pizza from the neighborhood takeout.

It is still for history to decide whether fax is a technology that will fundamentally change the way Americans live and work or merely a transitional gadget before a more profound breakthrough. At such close distance, it is often hard to tell.

In the 19th century, some forward-looking people were abuzz over the pneumatic tube, a hollow pipe along which cylinders are propelled by forced air. Build great networks of tubes across cities, they said, to whisk cash, mail, commodities, perhaps even people, at unheard of speed and convenience.

The tubes did see duty moving cash around dime stores, paper around newspaper offices and express letters between post offices (the French postal system ran such a system in Paris until 1984). Tubes remain in specialized use today. But by and large, the grand predictions seem a quaint, final protest of the mechanical age as electronics set in.

For all the fascination with the fax, more than a few technologists dismiss it as a latter-day pneumatic tube. All that fax can do is help people move more paper to more places more quickly. However commonplace it becomes, fax remains powerless to solve the most crushing problem -- namely, how to sort through all the information and images that bombard people in ever-growing volume and organize it so they can get at what they need when they need it.

For these fax skeptics, personal computers are the only valid solution. As prices drop, as the computers grow larger in number and easier to use, they will take on a larger role in communications, moving information at the lightning speed of fax but also helping out after it arrives. In seconds, computers can organize it, search through it and rearrange it at the commands of the humans for whom it is intended.

The skeptics see fax as a diversion, a better way to do the wrong thing. "I look at fax as a very temporary technology," said Rashi Glazer, a marketing professor at the University of California at Berkeley. Computer communications is being slowed by the hodgepodge of standards that prevents many machines from talking to each other. But once that problem is solved, said Glazer, "fax machines are obsolete."

Still, it is hard to dismiss as inconsequential machines that, according to the research firm Dataquest, are being bought at the rate of more than 4,700 a day and that people have been dreaming of for centuries. Fax fans contend that, whatever the "paperless society" pundits say, people love paper and will never willingly part with it. Fax has done a great service by bringing computer-age speed to the venerable medium.

Primitive forms of fax appeared in the 1840s, ungainly systems by which a pattern traced out by a stylus at one end was mimicked, using a telegraph link, by one at the other end. Today's machines, in contrast, harness modern micro-electronics to scan an inserted document in a few seconds and transmit data over telephone lines that allow a second machine to produce a copy of it.

The process was pioneered in the United States and Europe but was first brought to the mass market by Japan, which continues to dominate world sales. The reason Japan was out front was partly cultural: Its writing system does not adapt well to keyboards, creating natural demand in its domestic market for a means of sending hand-written documents electronically. Sales boomed in Japan, and by the second half of the 1980s they were taking off in the United States.

Anyone who deals in paper is a potential customer. The insurer Geico Corp. of Chevy Chase, for instance, today has a network of more than 50 fax machines, which it uses to move internal memos and documentation for claims that it wants to pay particularly quickly -- a body shop's estimate for fixing the dented fender, perhaps. Architects and commercial artists send clients their sketches -- and occasionally even their final drawings -- via fax. Airlines are preparing to introduce in-flight faxing for passengers.

The federal government, as paper-driven as any company, jumped for the technology, too. The Air Force has bought high-clarity and supposedly combat-rugged models that cost about 100 times more than ordinary machines. The Washington-Moscow "hotline" uses fax.

Overnight, fax has become a staple of international communications. One reason is that it eliminates the need for one party to get out of bed to talk by phone to the other in a different time zone. Instead, faxes are exchanged overnight. By some estimates, roughly half of all calls between the United States and Japan these days are carrying not talk but fax.

New uses, some that may be short-lived, are appearing rapid-fire. Junk fax (a fax that tries to sell you something), the faxed newsletter, the faxed song request, the faxed birthday card, the faxed carry-out order.

Fuddruckers, a hamburger restaurant in Falls Church, is trying that last one, taking in about five orders a day. General Manager Butch Michalick said office workers pass an order form from desk to desk at lunchtime, then fax it in. His staff is not constantly having to run to answer the phone. "It's saving time for us and saving time for them," he said.

Other items that move on the office fax machine, some of them when the boss is not looking: football pool forms, re'sume's, clippings a friend should read. Proud parents have faxed the footprints of newborn babies. Tennis star Jennifer Capriati gets homework assignments by fax on the road. Paleontologists have compared diagrams by fax while crafting a dinosaur model.

Fax has become a standard tool in politics. The Senate's fax center, for instance, last year handled 2 million pages. The secessionist government in Lithuania uses fax to get its message to the outside world. In China, dissidents recently flooded Beijing fax machines with messages urging people to "take a walk to Tiananmen Square" to commemorate last year's democracy demonstrations there.

And criminals big and small have joined the craze. South American drug cartels, being businesses as well as criminal organizations, use fax to keep in touch. Closer to home, a bomb threat was delivered by fax to a company in Crystal City earlier this year. Companies occasionally get faxes after deadline that look like they came on time -- the clock on the originating machine has been temporarily reset to create a false time code on the arriving paper.

At one level, the fax fascination is easy enough to understand -- as often as not, fax is cheaper, easier and faster than other forms of staying in touch. The mail takes days; a courier takes hours and costs dearly. Fax moves in seconds. Unlike a phone conversation, it can convey pictures, charts, graphics, doodles, handwriting. Unlike telephone calls, it leaves a record. Unlike telex, it is cheap, and portable versions of the machines can be plugged into a hotel room socket or a client's office.

Falling prices also have driven up demand. Basic models can be had for about $400 and a few people foresee a "personal" fax machine, cheap enough to go in every home in America. Manufacturers have in the meantime been continually improving their wares: Pricey models can transmit faster, include a telephone, use regular paper rather than the standard shiny thermal variety, handle color, transmit at night when long-distance charges are low, and even work with the cellular phone in cars. MCI Communications Corp., meanwhile, offers a fax "broadcast" service that makes it possible to send the same document to any number of different locations as easily as it is to send it to one.

Special circuitry will now turn your personal computer into a fax machine. Hit a key and the memo on your screen is transmitted to a fax machine and emerges as a paper document, or vice versa. (Alas, it takes software beyond the financial reach of most people for the PC to "read" an incoming fax and sort its information.)

But clearly, social forces have been at work, too. In the beginning, a fax machine was a prestige acquisition, proof that you were technologically hip. Now, it may be valued as an extra channel into an outside organization and, in some cases, a psychological tool by which to try to manipulate the people there. Henry Breitrose, a Stanford University professor of communication, suggests that many people who fax are just trying to create a sense of urgency, to get their item to the top of the pile.

Perhaps just as important, faxing is fun. "People seem to enjoy it," said Peter McWilliams, a California author who writes about consumer electronics. "There's something magical and mystical and you don't have to learn anything." Computers, in contrast, require hours of training just to learn basics.

For whatever reasons, fax use has grown so rapidly that the user often can't keep up -- no sooner is a new machine installed than it is as overworked as the older ones and the ease and convenience are lost. Fax congestion has created a new point of office-worker congregation. "People are no longer hanging out by the water cooler," joked Chris Kelly, assistant office manager at the public relations firm Daniel J. Edelman's Washington office, which in March sent out close to 2,500 faxes, mostly to clients, and received somewhat fewer than that. "They're hanging out by the fax machine."

One byproduct welcomed by some educators: The machines have nudged Americans away from doing everything by word of mouth, on the telephone. "I'm delighted to see the return of a written culture," said Breitrose, noting that fax promotes "the notion of correspondence and people setting their ideas down."

But do fax machines raise productivity? This is perhaps the heart of the debate over the machine and its place in technological history. It may be more convenient to have paper arrive in a minute instead of an hour or a day or a week, but does it really allow workers to produce more goods and services, as the telephone surely did? Does it liberate people from mundane tasks so that more time can be devoted to creative endeavors?

In many American offices, fax has served to create more messages than existed before, not a few of them unwanted. People may never get to all the faxes that pile up on their desks. Even if they do, they may have no time to act on them. It is much like a newly opened highway: The purpose is to ease congestion, but it can generate so much new traffic that before long it's as jammed as all the rest.

Glazer of the University of California said that fax is mimicking almost every communications breakthrough of history. So much rushes into the new pipeline that people at the other end are overwhelmed. "The amount of information ... moving around is perhaps greater than our ability to handle it," he said.

For evidence that he may be right, look to Georgia-Pacific Corp., a large forest products company based in Atlanta. Faxes coming into its communications center can take hours to get to the people they are intended for. So now, they are popped into an ultra-modern system for final delivery: pneumatic tubes, which zip them to any of 21 floors in the company's downtown skyscraper -- in seconds.