(Bob Levey is on leave until early January. His daughter Emily is teaching him how to be a father. In his absence, the column, and the fund-raising drive for Children's Hospital, have been taken over by Rob Graettinger).

"Santa's bike won't start."

The first engine had kicked in at precisely 1 p.m. last Monday afternoon. But, Bill Lumpkin, sitting astride his Harley-Davidson motorcycle, his long white beard and bright red suit flapping in the breeze, could not get his motorcycle to kick start.

"We'll have to push start it," one of the elves shouted. By this time, the parking lot of the Silver Spring station of the Montgomery County police echoed with the sound of nine super-size Harley-Davidson motorcycles. And Santa needed a push start.

Two elves grabbed the rear end of the bike and pushed it down the incline until a puff of smoke signaled that Santa was ready to roll.

Finally, the sirens roared, and Santa and his elves-on-wheels moved out of the lot past two well-wrapped elderly women staring in disbelief as the figure of Saint Nicholas sped out onto Sligo Avenue.

As the motorcade passed down the block and made its turn onto Georgia Avenue, the reaction of motorists and pedestrians was almost always the same. First, a glance and then a smile, and sometimes a wave.

At the District line, the group picked up an escort of three D.C. motorcycle policemen and turned off toward Blair Road.

On North Capitol Street, two young children sporting backpacks stared wide-eyed when they first saw Santa, then burst into brilliant smiles as the holiday motorcycle gang sped off into the distance.

Suddenly, the motorcade was on an open stretch of North Capitol. The bikers gunned their engines, the sirens fell silent and there was time to think about this good-natured fellow, Bill Lumpkin, and his friends on the force who collaborate each year to raise money and collect presents for distribution at Children's Hospital.

Bill Lumpkin began the Santa Claus motorcycle gang as a solo number. He is a towering sort of fellow with a congenial temperament and an infectious smile.

On Christmas Eve, 1974, Lumpkin said, he was motoring around the parking lot of the Siver Spring police station during the noon hour in a Santa Claus costume he planned to wear to his brother's Christmas party. He pulled to the edge of the lot, wondering what a short ride through the streets would do for the neighborhood kids, and looked up to see his captain looking at him from a second-floor balcony.

The captain waved him out onto the street. And, with that, the "Santa Claus motorcycle division" was born.

Lumpkin's major concern at the time, he said, was that higher-ups might complain about the officer who had been racing up and down Rockville Pike in a Santa Claus costume.

The reaction was, in fact, just the opposite.

He was jokingly reprimanded for not visiting any other police stations.

The next year, 1975, with his wife 8 1/2 months pregnant, he said, "the trip really meant something."

Their son, Billy, was admitted to Children's the day after he was born with a rare cardiac condition. He spent 11 of the next 15 months in the hospital and died in April, 1977.

During Billy's 17 admissions to the hospital, the Lumpkins came to know the staff at Children's well. "It was rough," Lumpkin said, "But if it hadn't been for the people down here, it would have been a lot rougher."

Billy became a well-known and well-loved patient, said Children's development director Alfred Lawson. "He and his parents were very popular."

According to the boy's father, "he touched more people in 15 months than most people touch in a lifetime." The friendships developed during that period, Lumpkin said, inspired him to expand his Santa Claus effort to other units.

According to Officer Bill O'Toole, who drove one of the accompanying squad cars the other day, the trip has expanded to the point that there now are nine station stops to pick up gifts on the way to Children's.

"We had eight elves this time," Lumpkin said, a smile creasing his cheeks.

Lumpkin said that the best part of the effort is the contribution that others make. In addition to giving their personal time, officers of the Montgomery County force managed to raise $11,000 for Children's Hospital this year. One way was through a raffle held Monday. The prizes included a pair of boxing gloves autographed by Sugar Ray Leonard and a football signed by all the members of the Redskins squad.

It is uplifting to talk to these people. They genuinely seem to enjoy the journey.

"Just to look at the expressions on peoples' faces," Lumpkin said. "Someone has a grump on his face when he first sees you, then he smiles and before you know it, everybody's waving."

Lumpkin smiled when I asked how long he planned to keep the Santa Claus patrol on wheels. "Well," he said, "I have eight more Christmases after this one before I am eligible for retirement."

"Are you going to continue with it after you retire?" I asked.

He laughed and said, "If they supply the escort, I'll buy a motorcycle."