For more than 650 years, they were the "common people's clock." Drums and bells atop towers near the imperial palace sounded across the tiled rooftops of sleeping Beijing to mark the hours through the night. They outlasted three Chinese dynasties before falling silent in 1924.

Yesterday, the tradition resumed. A group of teen-age martial arts students climbed the steep stone stairs of the Drum Tower and beat a set of drums that are up to 1.6 meters across as the bell in a nearby tower rings.

It's part of scattered efforts to save at least a hint of antique Beijing in an aggressively modernizing Chinese capital that is tearing down imperial-era buildings to make way for shopping malls, apartments and wide avenues, the Associated Press reported.

"We're doing this because it is a central part of the city's history. This was the common people's clock," said Zhu Yingli, a manager of the city agency that looks after the 47-meter-high Drum Tower and, 200 meters away, its companion Bell Tower.

The drumming is to become a daily event, repeated twice each morning and afternoon for tourists, Zhu said in an interview in her tiny, book-filled office at the base of the Drum Tower.

Earlier this month, Beijing officials announced plans to rebuild part of the old city wall and preserve a handful of historic sites.

The wall to be restored was built in 1531-48 during the Ming Dynasty.

The government appealed for families to return bricks that they kept. Officials say they have collec-ted about 200,000 but need 2 million.

The city said it would issue a relic-protection plan early next year for a 23-square-kilometer area of its old city. It includes two palaces once used by princes.

The Drum Tower has long been one of the city's most prominent buildings, its ornately painted wooden upper story and gray stone base looming above maze-like lanes of one-story brick houses.

It was first used in 1272. Drums and bells were sounded at 7 p.m. and then every two hours through the night, each time in a pattern of exactly 108 beats.

The tower is set due north of the palace in the grid of streets that defined imperial Beijing. Its time-keeping added a dimension to rulers' efforts to impose similar rigid order on daily life.

Twice the tower burned and was rebuilt - the last time in 1420. Drumming carried on through the Ming and Qing dynasties and survived the 1911 revolution that ended imperial rule. It didn't end until Puyi, the deposed last emperor, was finally evicted from the palace in 1924 and left Beijing.

Even after the founding of the People's Republic of China in 1949, the Drum Tower was regarded as special. The central government declared it a national treasure.

The Bell Tower is already in limited use, with its bronze bell struck annually at the start of the Chinese lunar new year every year.

In preparation for yesterday's relaunch, the red-columned room at the top of the Drum Tower was renovated and new drums made. The head for the biggest required the entire skin of a bull.

But there is a limit to how much history officials want to revive. Zhu said they have drawn the line at having the drums beaten at night.

"If we did it then, ordinary people will not be able to sleep," she said.

(Eastday.com January 1, 2002)