The mirror was designed by Emilio Barlocco, an engineer whose company specializes in using reflected sunlight to light the entrances to highway tunnels. He read about Viganella's plight on the front page of the Turin daily La Stampa and offered the village his expertise and services. "Whenever you do something for the first time, you're either a pioneer or stupid," he said. "We hope we're the former."

A concrete plinth was anchored to the rock face of the slope above Viganella to serve as the mirror's base. The mirror panels were flown up by helicopter. The software that tracks the sun's rotation is so sophisticated that the rays can be directed anywhere by the computer, which is in the town hall. "If the church or the bar in the town next door has an event, like a baptism, or a wedding, we can shoot the rays there," Midali said. "It's very versatile."

Curiosity about the mirror, Midali hopes, will improve Viganella's fortunes, which have flagged in recent decades as steel and manufacturing plants in the surrounding valleys shut down.

The stone houses of the once-thriving historic center now come to life only as summer homes for vacationing families, mostly from Turin and Milan. And with a resident year-round population of fewer than 200 (including a resident colony of about 40 European Buddhists) the village has no stores, no post offices, doctors, or schools; the 12 resident children are bused to school in nearby villages.

Since the mirror became operational in December, Midali said, he has had visits from journalists, curiosity seekers, a Canadian documentary film troupe and delegations from other towns forced to live in the dark in Italy, Austria, Switzerland and Norway.

"Towns like ours represent the real heart of the Alps, but we're usually in the shadows of the chichi ski resorts, and don't get noticed," Midali said, citing renowned Alpine sites like Sestriere, Italy. "Sure they're rich, but they've lost their identity."

On Sunday, the nonworking day closest to Feb. 2, the town made the most of its traditions. A pine tree decorated with slabs of local cheese, salami sausages and bright tea towels was blessed by a local priest before the branches were sawed off and auctioned. A handful of women dressed in the dark local costume paraded through the town square, with brightly festooned coverings resembling oversized jewelry trees on their head.