There were many Lowells.
The first Lowell was farmland intersected by the rushing waters of the Concord and Merrimack Rivers. The second Lowell was more a mill machine than a landscape - architecture as turbine, the harness whereby those waters powered the looms that began the American Industrial Revolution.
The third and the fourth and the other Lowells that followed must be numbered more randomly, counted by the waves of immigrant workers and the growing nexus of buildings that housed their labor as the town and its industry grew.
There were the Lowells that evolved in time from the Lowell that was a model architectural community, a planned ensemble, to the Lowell of 100 years later, the post-World War I Lowell, desolate as the garment industry fled south and Americans forsook the city.
And today's Lowell?
The latest Spindle City is in many ways a new place. It is a born-again New Town, launched by natives and polished in Washington. It is the place that preservation and history have built on the infrastructure of the past.
Approaching the first year since it was established as the Lowell National Historical Park, with a newly finished $12 million Visitor Center, $100 million worth of public investment, and maybe six times that in private funds, including 50 facade improvements in place, the city is unique in this country and perhaps in the history of planning and design.
Here, just off where the milk foam waters of the Merrimack energized what is now labeled ''the Other American Revolution,'' the city, the state, and the National Park Service have created a park without trees, a preserved plot that is not a hothouse for a liberty bell or a moment in history smothered in formaldehyde. The park provides a citywide view of mill and main street, canal and mansion defined as a living museum.
Spearheading the revival of storefronts, the recycling of mills into elderly and subsidized housing and workspace, and the $2 million in street fix-up and street furniture, a not always well-coordinated collection of agencies have revitalized the architecture and life of one of the ''nitty gritty'' cities of the Northeast.
In a period of slowdowns, cutbacks, curtailments, and a Park Service bent on shrinking its wild, not to mention urban, turf, the decade of architectural work at Lowell still has enough momentum to go on. The bottom-up beginning with Lowellites at the helm has ensured that despite shrinking federal support, the renovation goes on.
''In not so many years, Lowell will take its place among the gems of our national heritage, and visitors from throughout the United States and the world will add one more destination - Lowell - to their list of Yellowstone, Yosemite, Gettysburg, and a host of other national parks representing the quality and diversity of America's natural and cultural treasures,'' says the Park Service.
Of course Lowell, with its 5.6 miles of man-made canals, is a feat of landscaping and engineering too. The ''Venice of America'' came by its title through a stupendous muscling of the natural environment: ''the most important hydropower system in the country,'' Bill Barlow, chief of technical preservation and maintenance for the Park Service, puts it.
But Lowell and its $12 million Market Mills and Visitor Center complex which opened last summer are especially remarkable as urban testaments; they are summaries of today's Spirit of Recycle in an agency marked by its harking to the Call of the Wild.
The Market Mills complex binds together 250 units of rehabilitated housing by Boston architects Anderson, Notter, Finegold, with other mixed-use spaces, mostly done in the recycling staple of BB&B (butcher block and brick). ''A Brush With History'' section gives space to artists of community origins (if less than genius status). Food booths tenant an area labeled (breathe deep) ''The Melting Pot,'' designed by Endevor.
he adjacent visitor center offers a somewhat stagnant but attractively mounted exhibition on Lowell. An exceptionally lively film on the city's history by the firm Larson & Rosen runs in the handsomely renovated auditorium. Here is the focus for the park and the center for tours and interpretive programs to help tourists.
Other Lowell mills may not have survived so well; those not filled with computer companies and the like seem to succumb to fire, at the rate of one a year. But if business seems sluggish and a window is as likely to have plastic flowers as hand-dipped candles, Lowell remains a real place, as Fred Faust, director of the Lowell Historic Preservation Commission, puts it. ''We have rough edges, but we're real.''
Somehow, the inspiration of the Lowell superintendent of schools, Patrick Mogan, translated by well-placed politicians, then-U.S. Rep. Paul Tsongas and House Speaker Thomas P. (Tip) O'Neill, and input from state, federal, and preservation agencies, the Chamber of Commerce, and so forth, have produced legions of plans and volumes - all of this without stultifying the city.
Quite the contrary. A visitor returning after half a dozen years' absence finds signs of renewal everywhere. For every ugly incursion in the streetscape (a bank that constructs a driveway on a pedestrian corner or the grim facades of franchises), there are a dozen that either fit in the context or better it (the ornate Hildreth Building with its elegant green wrought iron; the Bay Bank building).
Work to restore or simply repair more of an estimated 1,000 historic buildings goes on and accounts for some of the 5,000 new jobs created in the town since the park was created. Equally important, these structures are subject to a sign-control system that calls a halt to the defacement of old buildings through gaudy billboards. Meanwhile, a design review process that might be the model for every town sets standards of good design and amends bad proposals.
One would hope, then, that such new and vital projects as the Lower Lock Complex - a $40 million proposal for a 250-room Hilton Inn designed by Skidmore, Owings & Merrill that would face a 100,000-square-foot Wang office setup, with $ 2 million in park amenities - will get the same scrutiny. Strict architectural controls are needed to save the first hotel from Statleresque banality and the Wang facilities from the bromidic-box architecture that usually marks computer company quickies.
Certainly such projects as the window competition for the 994 windows at the Wannalancit Office and Technology Center by Boston architects Perry, Dean & Rogers was a case study in the proper care and feeding of architectural detail. A retrofit workbook and submissions from six companies preceded the award. So, too, the firm's refurbishment of the 1923 Lowell Memorial Auditorium must be credited to the rare political and architectural process at work here.
Whether such labors can overcome the country's hard times and continue to work to renew this former ''Eldorado on the Merrimack'' as a kind of urban and bureaucratic laboratory remains to be seen. But whatever the future of what Mr. Barlow calls ''the Second Lowell Experiment,'' the confluence of countless agencies and individuals - like the confluence of the mighty rivers that launched this model town - will have major consequences here and throughout this country.