Macroengineer thinks on a scale as grand as Pharaohs'

FRANK Davidson is enough out of sync with the times to believe that big is beautiful. Make that very big.

Like building artificial islands - ''sea cities'' - off the East Coast of the United States, laden with power plants or serving as deep-water ports.

Like shunting high-speed trains between North America and Europe in a tunnel under the Atlantic.

Like damming Canada's James Bay to create a continental reservoir for transporting water to Arizona and Mexico.

There is a name for this kind of thinking - or heresy, if you like. It's called macroengineering, a term Mr. Davidson himself coined 16 years ago to describe the concept, for which he is still a leading ideological steward.

In this era of financial limits and lingering small-is-beautiful sentiment, macroengineering - the study, preparation, and management of the biggest technological projects that can be built at any given time - may seem outlandish. But macroengineers like Davidson believe it is again time for the United States and other countries to begin considering huge-scale projects to enhance the global standard of living. A lawyer by training, Davidson is lecturer and coordinator of the Macroengineering Research Group at the Massachusetts Institute of Technology's School of Engineering.

He lectures, writes, convenes conferences, and, like a modern Odysseus, frequently hopscotches about the globe (the macroengineer's drafting table) searching out others' grandiose schemes and convincing smaller-thinking humans of their value.

His message: Big problems require big solutions. Many challenges today - transportation, water, energy - demand bold, adventurous, and, yes, large leaps of the imagination and engineer's blueprint.

''If you have very big problems, you need solutions that are on the same scale,'' says Davidson over a roast beef and asparagus lunch in a fittingly cavernous dining room at the Harvard Club in Boston. ''All of us would like to find salvation in some very simple formula. But life is a little more complex than that.''

Macroengineers don't think in terms of building roads or bridges. They think in terms of changing the flow of seas, joining continents and oceans, or populating planets. Virtually every civilization has had its mega-masons who, for better or worse, have left indelible marks on the globe. There are the pyramids of Egypt, the Aztec aqueducts, the Roman roads, and the Grand Canal of China - a 1,300-mile canal system intermittently under construction from about 400 BC to the present.

In its brash days of growing up the US, too, produced its share of heroic engineering feats: the transcontinental railroad and the Erie Canal - the latter built in an eight-year period when no civil engineering degree was yet granted in the US. And the Panama Canal, conquering jungle and mountain to join the Atlantic and Pacific (and in the process creating a nation).

America's more modern times have seen the opening of the St. Lawrence Seaway and a lunar landing.

Often these megaworks and the people behind them roused entire nations. In ancient Egypt, for example, the architects of some pyramids were virtually deified. When opened in 1883, New York's Brooklyn Bridge was revered not only as a triumph of engineering and architecture. It profoundly affected painters and poets as well.

A comparable project today, however, might bring a congressional inquiry or environmental lawsuit. Which is what worries people like Frank Davidson. This tweedy troubador of the large-scale doesn't advocate a return to the worship of bigness: Blind faith can beget blunders. Nor does he eschew smallness. When teaching macroengineering at MIT, in fact, one of the first books he urges students to read is E. F. Schumacher's ''Small is Beautiful.'' It's not to familiarize them with a warped view of a utopian world of windmills and electric cars, he says, but to let them know why Schumacher is right - why what is important isn't size but appropriateness.

''If you read what Schumacher really said, he said we need big systems and little systems,'' says Davidson. ''It all depends on what you're trying to do. Schumacher also said that if people started trying to solve every problem on Earth with a little system, he'd have to write a book on behalf of big ones.''

There would be no need for that, of course, since Davidson himself has already done so. Quiet, unassuming, he chats calmly about sending manned missions to Mars, piping water along the seabed from Alaska to Arizona, progress on the controversial English Channel tunnel, and figuring out some way to transport water to drought-ridden Africa. The fact that many others aren't discussing the same ideas perhaps shouldn't be surprising. For one thing, this is supposed to be an era of limits, the waist-deep budget deficits and high interest rates in the US, for example. Any large project, moreover, would surely entail hefty government involvement - something not popular at the moment.

''The problem now, obviously, is that so many of these things require some type of federal support, and we are in a period of budgetary restraint,'' says Wallace O. Sellers, director of diversification and development at Merrill Lynch & Co., which follows the macroengineering field.

For another, the 1960s and '70s reminded us that big technology has social and environmental consequences. You don't strip-mine the West just because there is ore underneath. Even before this there were macroprojects that produced macroproblems. Davidson himself cites early railroads that went bankrupt, some dams that triggered earthquakes, and a few public-housing projects. Nuclear power has done nothing to instill public confidence in big construction, either. Yet size, he says, need not always mean environmental damage.

Finally, modern government itself may be a culprit. Ambitious projects have always stirred controversy. Even the Eiffel Tower drew lawsuits and public scorn , because many Parisians thought it an eyesore. Today, however, particularly in the US, some argue that megaworks involve so many players and approvals that reaching a consensus requires as much politics as engineering.

''The country has matured in a way that has fragmented the decisionmaking process,'' says A. George Schillinger, chairman of the Division of Management at New York's Polytechnic Institute and executive director of the American Society for Macroengineering.

Davidson is less circumspect. ''We're in danger of becoming a nation of consultants,'' he says. ''The Japanese are going ahead with artificial islands. We publish books and hold conferences.''

There are signs, though, that the US is regaining its ability to think big. Current enthusiasm about space is one example. Davidson would like to see some of that same spirit applied to other frontiers. Some ideas he considers worthy of consideration:

*Artificial islands. Floating platforms could be built for use as offshore power plants, deep-water ports, solid-waste sites, or even small cities.

*Water. A network similar to North America's electric power system could transport fresh water. One idea is to dam James Bay, transport the water to the Great Lakes, then distribute it to the arid Southwest.

*Transportation. One scheme calls for laying a high-speed rail link between the Americas, zipping people between, say, Boston and Buenos Aires.

*National bikeway. One of his favorite projects, and an original with him, is a national bikeway for the US, linking Maine with California.