People used to call this place "Slab City.” But that was back in the 1750s, when every building and fence in North Adams was built with the leftover planks from Elisha Jones's sawmill.

The planks have long since rotted and returned to the earth; so has the sawmill. The hat manufacturers, machine shops, and ironworks that took its place have vanished, too. But the spot where they once stood is perfect for musings on the course of economic change - what was and what still might be.

Sic transit gloria mundi - "Thus passes the glory of the world” - could easily double as the official motto of North Adams. From sawmill hand to weaver to electronics factory operative, all prospered here. Each, in turn, grappled with the uncertainties of change as the region's economy evolved from natural resources to textiles, and finally to high-tech manufacturing.

Now there are signs - actual signs - that this faded blue-collar city is on the verge of another economic transformation that will take it into the postindustrial age. The first to catch my eye is a hand-carved beauty that hangs from a darkened mill building at the eastern approach to town "Delftree Farm Store - Shiitake Mushrooms.” I'm not exactly sure what shiitake mushrooms are, but I know they're upscale. And over on Main Street, a new marquee graces the Mohawk Theater.

But the clearest signs of the new information/entertainment economy are those that point the way to MASS MoCA, the Massachusetts Museum of Contemporary Art, which sprawls across a portion of the historic Marshall Street mill complex. Ghosts of North Adams's industrial past are everywhere in evidence on this parcel of land where Elisha Jones's sawmill once stood. In some ways, the setting shares star billing with MASS MoCA's collection.

Old-timers occasionally still refer to the Marshall Street complex as "Arnold Print” or "Sprague's” - a nod to the two companies that were the economic anchors of northern Berkshire County for more than a hundred years. Arnold Print Works began manufacturing plain and printed fabric on the site in 1860 - just in time to prosper from supplying cloth to the Union Army during the Civil War. When a fire destroyed its original operation in 1871, the company began construction on the red brick Victorian mills that are now home to MASS MoCA.

At its peak in the early 1900s, Arnold Print employed 3,200 people, but in 1942 competitive pressures forced it to close up shop at Marshall Street. Not long after that Sprague Electric bought the complex and moved in from across town. Sprague flourished supplying defense-related electronic components to the U.S. armed forces during WW II and the Cold War. But by the late 1970s, labor strife, rising energy costs, and foreign competition started to take their toll. In 1985, when Sprague turned out the lights at Marshall Street for the last time, there was little prospect of finding another industrial employer to restore even a fraction of the 4,000 jobs that had disappeared.

There was only an idea - a fanciful-sounding proposal, hatched at the Williams College Museum of Art in 1986 and nurtured in North Adams City Hall - to exhibit oversized contemporary art in the vacant mills. Over the next 13 years, a coalition, which also included local business interests, state government, and the Guggenheim Museum, struggled to transform the derelict mill into the largest center for contemporary arts in the United States.

With 220,000 square feet of galleries, performance spaces, fabrication facilities, and mixed-use commercial space, MASS MoCA bills itself as a "supercollider for the arts.” Its 100,000 feet of gallery space allow it to display large contemporary pieces that big-city museums simply can't afford to accommodate - pieces like The 1/4 Mile or 2 Furlong Piece, painter Robert Rauschenberg"s 1,000-foot-long work in progress. The gallery where it hangs is big enough to have held a 300-foot table for rolling out cloth.

The table has been gone for years, but vestiges of the past are everywhere. Ancient fire doors still maintain their vigil. Adjoining swatches of pink and green paint mark the spot, midway up a brick wall, where a ladies' room and a men's room stood side by side. The 80-foot clocktower that once obliged people to adjust the rhythms of their lives to the demands of industrial production now welcomes art lovers and vacationers to stroll at their own pace.

Which raises the issue of whether or not MASS MoCA can take North Adams from lunch pail to leisure. Can a "supercollider for the arts” and an old blue-collar factory city - the oddest of odd couples - find long-term happiness together? The ladies down at the tourist information center on Union Street seemed to think so.

"You know, dear,” says one, "We're a little spoiled here because we have the Clark Art Institute and the Williams College Museum of Art.”

"But be sure to visit MASS MoCA,” chimes another. "I'm not a modern art expert, but the museum is wonderful. The art makes you think. It doesn't do the work for you.”

The third lady, who hasn't said much, starts to chuckle over 2 x 18 Aluminum Lock, Carl Andre's minimalist sculpture, which looks for all the world like an aluminum walkway in the middle of a gallery floor. "When I told my grown son not to step on the art, he said, 'Sorry, I didn't know I was.' ”

But the ladies are right. The art does make you work. One of the museum security people notices that I"m having a tough time with None Sing - Neon Sign (it's an anagram as well as a work of art). "Each piece has a card to give you background information,” she explains. "Here's one for the upside-down trees.”

When I look at her blankly, she smiles.

"Don't worry. You're not the only one. People miss them all the time.”

The upside-down trees - a.k.a. Tree Logic by Australian-born artist Natalie Jeremijenko - are six live maples, inverted and suspended from individual stainless-steel planters above a walkway that led to the main gate at Arnold Print and Sprague Electric. The foliage canopies were where I had expected them to be; my mind's eye had filled in the trunks. "Slab City” revisited - only this time the slab is my head. It makes me wonder if the generations of mill hands and assemblers who passed this way were as heedless of their surroundings as I am.

A planned 30-minute visit turns into a full afternoon. I hadn't expected to enjoy myself this much; most museums make my feet hurt. But there are times when it's fun to discover how far off the mark you can be, and this was turning out to be one of them.

Just before closing time, I run back upstairs; partly because I want a few more minutes with the art, but also because . . . I'm not exactly sure why. There's something about the second-floor gallery - the light, the mood, a vague sense of anticipation.

At the top of the stairs, I turn toward the lead-covered spiral table created by Mario Merz, a pillar of Italy's Arte Povera movement, whose members, according to one of MASS MoCA's cards, challenged "the increasing dehumanization of the modern industrial world through their meditation on food, dwellings, and the encounter of nature and technology.” A few feet away are two of Merz's igloos; one covered with branches and neon, the other with glass and stone - one ancient, one modern. I'm looking at them, thinking how cozy they seem.

And that's when I sense it.

There's not another soul in the gallery. Or not another living person anyway. Yet, just on the other side of the fading light, the mill hands and assemblers and supervisors, who spent so much of their lives in this place, are waiting for me to leave. And when I do, they'll huddle together in the igloos to talk about old times, or gather around the spiral table for one more company social.

Robert Jabaily is an editor in the Research Department of the Boston Fed.