An old downtown Washington landmark became, in a sense, a new landmark yesterday. A topping-off ceremony was held for the reconstructed Army and Navy Club building at 17th and I streets NW, marking the end of steel and concrete work that raised the 73-year-old building from eight to 12 stories above ground, plus five levels underground.

An announcement said the ceremony would be held on the rooftop, overlooking Farragut Square, but there is no public elevator. So the British development firm of Farragut Associates stayed indoors. Nobody saw the top.

"It was," quipped retired Army Reserves Maj. Gen. Donald S. Dawson, the club vice president, "the first topping-off ceremony ever held in the basement." Well, not quite the basement: the ground floor.

The ceremony also marked the club's centennial. It was founded in 1885 by military officers who met above old Klotz's restaurant and bar in the 1700 block of G Street NW, where the Federal Deposit Insurance Corp. is now.

At first, the club was called the United Service Club, adopting its present name in 1891 as it was preparing to move to its first "permanent" home -- a turreted brick building, directly across I Street, that stood until 1962. In 1912, the club moved across the street.

The club was used in 1955 by a Hollywood studio for scenes in the movie, "The Court Martial of Billy Mitchell," starring Gary Cooper and Ralph Bellamy. Some of the crusty old "Indian fighters," as elder members were then affectionately nicknamed, protested the intrusion bitterly.

As the club's officer-members aged and so did the building, the problem of an economic way to maintain the clubhouse grew more acute. A solution was offered by British developers John Divett and Stephan Wingate. Under their plan, the building was gutted but its original facades retained (a sometimes criticized technique which, to me, is preferable to losing all our cherished but obsolete landmarks).

When completed next spring, the building will have three levels of underground parking, two levels of underground health club, grill and administrative space and four levels of above-ground club space, including 29 rooms for visiting members. The top eight floors will be rented as offices.

At yesterday's ceremony, retired Marine Corps Brig. Gen. James D. Hittle, the current club president, praised the developers, the builders and the hard-hat workmen, who were invited to end their work shift with a cold beer.

On hand for the event was Stanley Newman, a former New Zealand Army officer visiting Washington on a civilian mission. He carried a plaque presented by the Canterbury Club in the city of Christchurch, his nation's equivalent of the Army and Navy Club which, by coincidence, also marked its centennial this year.