A Traveler Through Our Times : The public art of architect/sculptor Maya Lin marks key eras in America: the Vietnam Veterans Memorial and her civil rights monument in Alabama. Now, she takes on time itself.

“Hi. You’re early,” says Ma ya Lin hurriedly, as she appears out of the throng in Penn Station.

With that, the famed creator of the Vietnam Veterans Memorial leaves a waiting visitor and climbs on a hydraulic lift to the scaffolding around her newest public art project, some 15 feet above the crowd. Like a White Rabbit in Commuterland, Lin has no time to talk, on this day in late July, to anyone but the crew: The earthbound visitor may be early, but the project is running late.

Early, late. Time has been weighing heavily on the architect/sculptor as the deadline for her work--an artistic focal point of the $190-million Penn Station renovation--has pressed ever closer. There’s a certain irony here, since the piece is itself about time. Designed to suggest a lunar eclipse, the work is part timepiece, part overhead sculpture: When “Eclipsed Time” has its long-delayed public unveiling in early fall, it will mark the hours for some 250,000 people who hurtle daily through Penn Station, while providing a visual fulcrum between the new 34th Street entrance and the vaulted passage that runs east to west through the cavernous underground transportation hub.

What will Long Island and subway commuters see--if they actually take the time to look up? A large oval form enclosing a frosted-glass disk on which the numbers 1 through 11 have been etched. Behind the glass disk is yet another disk, of brushed aluminum.

As the aluminum disk moves across the glass, it eclipses the numbers, until at midnight the disks are aligned and the work is dark, except for a soft halo; at noon, by contrast, the glass is completely illuminated, via a complex fiber-optic system that culminates in hundreds of pinpoints of light.

That is the plan--elegant and artistically minimal--and it has been working perfectly in Lin’s Bowery studio. But there have been inevitable snags during the installation of the massive piece in Penn Station.

“It’s been 2 1/2 weeks of incredible stress,” says Lin, relenting enough to allow her visitor briefly up on the scaffold. A slight figure in her chinos, she deals equably with the ironworkers and electricians to sort out the latest hitches in the schedule. Flaws have been detected in the frosted glass disk, and Lin is awaiting the arrival of an emergency order of “etching cream.”

A newly discovered structural beam in the ceiling has interfered with the placement of a transformer box containing halogen bulbs and the box will have to be moved. The delay has made the architect visibly anxious, and even less happy than usual about being the focus of media attention.

An intensely private person, Lin has been celebrated for 13 years--ever since she designed the Vietnam Veterans Memorial in Washington--for making public art. “It’s a paradox,” admits the 34-year-old artist. “I really believe that the work is public, but I’m not.”

Maybe her skittishness stems from the furor she faced as a 21-year-old Yale architecture student when her design for a V-shaped memorial of black granite was selected over hundreds of other entries in a nationwide competition. It comes almost as a shock to recall, now that the memorial has become a virtual icon of its era, what anger it once stirred in those who thought it “demeaning” to veterans. “A black gash of shame and sorrow” is how one leader of a Vietnam veterans’ group described it.

As an Asian American woman, Lin also endured personal slurs--political, sexist and racist--before the controversy died down and she was able to escape the limelight for a time.

Yet when she re-emerged, it was with another public memorial: a monument honoring the civil rights movement commissioned in 1988 by the Southern Poverty Law Center.

I ts 1989 dedication in Montgom ery, Ala., marked the end of her involvement with public memorials, Lin says: “I was fortunate enough to work on (monuments for) two wars of our era. With the completion of the Civil Rights Memorial in 1989, I very happily laid that to rest.”

She has been working since on a variety of projects, including a renovation of the Museum for African Art in SoHo, a sculpture commemorating more than two decades of undergraduate coeducation at Yale and a three-story garden of crushed glass for the Wexner Center for the Arts at The Ohio State University. She’s even completing her first commissions to design private homes--one in Santa Monica, the other in Williamstown, Mass. And she is pursuing her interest in environmental issues through contact with several groups that have been exploring a possible paper recycling plant in the South Bronx.

But for the past several weeks, all her fine-tuned energies have been concentrated on the Penn Station clock. Its installation marks the culmination of five years of effort, ever since Lin’s design was selected in an invitational competition sponsored by the Metropolitan Transportation Authority’s Arts for Transit program. (Because of the enormous area covered by the renovation, two artists were chosen to enhance the look of Penn Station; terra-cotta bas reliefs by Andrew Leicester adorn several walls of the site.)

The work was judged by a panel that included artists Chuck Close and Mel Edwards, as well as some well-known curators and a representative of the Long Island Rail Road. “This was a very sophisticated panel,” says panel chairwoman Wendy Feuer, director of the Arts for Transit program, which can allocate up to 1% of MTA construction budgets for art in subway and railroad stations. (Given the scope of the Penn Station renovation, though, the art allocation was nowhere near 1%, Feuer notes.) “They were interested in reviewing the work of artists who worked environmentally, who had national and international reputations and whose work conceptually could encompass large and disparate areas,” Feuer explains.

Nor was that all. The design requirements, recalls Lin, included some important negatives: “Viewers couldn’t touch it. It couldn’t slow down traffic. It couldn’t have seating.

“I thought, what a challenge!,” says Lin, warming quickly to her subject once she takes a brief break from the problems on the scaffold. “Given all these, how can you still communicate?”

The trick, as Lin puts it, was to create a “one-on-one dialogue,” despite the limitations. In fact, all her public work--beginning with the Vietnam Veterans Memorial and its thousands of inscribed names of the dead or missing--has endeavored to do just that: to take the massive and public and reduce it to the individual and private.

And though “Eclipsed Time “ is her first interior art installation, with unique problems, Lin’s goal is still “creating one still moment” in the organized chaos of Penn Station. The concept of a lunar eclipse, both romantic and familiar, is her way of saying stop, look and--if you have the time--think.

“What’s really ironic,” says Lin, by now bubbling with enthusiasm, “is that though it deals with motion, you can’t see it move. Though it deals with the passage of time, you’d really have to stand still to see the disk move.”

But standing still is at a premium. Problems beckon up on the scaffold. In a few minutes, time’s up for Maya Lin’s visitor, who watches the slender figure in chinos weave back through Penn Station to play with time in her art.