In their carnival-colored T-shirts, their out-at-the-toe sneakers, their pinned-on ribbons for work and play well done, 660 children left Algonkian Elementary School as boisterously on the last day as they had arrived cautiously on the first.

Decibel for decibel, hug for high-five, their exuberance was matched by Principal Preston Coppels, who waved the new school's first students away for the summer June 13 even more heartily -- if that was possible -- than he had waved them in for the fall.

" 'Bye, kids!" he called to another onrushing tide of children spilling out the front door of the school in Countryside. "Have a great summer! See you, Heather . . . See you, Jason . . . So long! Good luck . . . . Austin! You made it! All right! Third grade next year!"

On the front end of this process -- when he met their arriving buses Sept. 5 and greeted their skeptical faces with "Hi, kids! You're going to have a great year!" -- Coppels was a new kid on the block, too, having just arrived from a 1,000-student school in New Orleans to open Algonkian.

Then, he said in an interview this month, "it was just a building. No one was certain what it was going to be. Now we've established some traditions."

Some of those instant traditions derive from his roots in "Nwawlins," as the name of his hometown is pronounced by natives.

He describes, for instance, the time he heard, from the music room adjacent to his office, the familiar strains of "When the Saints Go Marching In."

Unable to resist, he went in to join the chorus and announced that if they were going to sing New Orleans songs, they were going to learn "to dance like New Orleans."

He went back to his office to retrieve his Benson Boogie Umbrella (so named for Tom Benson, owner of the New Orleans Saints football team) and returned to instruct the children in the finer points of the "Second Line," a dance wherein someone leads with the umbrella and everyone else boogies along behind waving handkerchiefs.

That day's dancing was confined to the music room, but come Mardi Gras, "we Second-Lined around the building," Coppels said, and he had the cafeteria chef bake the customary King Cakes that day.

This may help explain why teachers and students, asked to describe Coppels, invariably agreed on at least one thing:

"He's nice, he's funny," said fifth-grader Matt Remen, winner of the Sterling Ruritan Club's outstanding-student award at Algonkian this year.

"He's fun," chorused several teachers sharing lunch in the lounge.

But many more of Algonkian's year-old traditions appear to derive from Coppels' conviction that school must be "humanistic," a warm, friendly place that makes teachers want to teach and students want to learn.

It begins with something as simple as music piped over the public address system when the children arrive in the morning, classical to country.

On the last day of school, it was "Pomp and Circumstance" in honor of the fifth-graders who will be going on to middle school next year.

Every Friday, a different theme -- Beach Day or Pajama Day or Favorite Sports Team T-shirt Day -- determines the choice of music and allows the children to dress accordingly. ("Just to make Fridays a little different," Coppels said.)

Someone is always at the door to greet the children in the morning, Coppels said, and if they must come to the office, they are greeted with a smile, not a bark.

In the classroom, "they're not made to feel ashamed if they've done something wrong. They're not afraid to make mistakes -- that's part of the process of learning," he said.

Student-of-the-Week and Student-of-the-Month awards are made not just for academic brilliance but to children who do something nice for someone else or improve their grades.

"It's competition in the fairest sense of the word," he said.

Coppels said the key "is getting people in the building who care . . . . You worry, because what you see in an interview may be different when they get together. If I've done anything right this year, it's assembling this group of people. They're fantastic."

His enthusiasm is reciprocated. "He always looks at things from the kids' point of view," said guidance counselor Dave Lienhardt.

"He treats us as professionals," teacher Mary Swartzbaugh said. "He's not hiding around a corner, checking on whether you're doing your job. He expects it."

The teachers said Coppels' expansive style is well complemented behind the scenes by Assistant Principal Patricia N. Forrer, a self-described detail person.

"If you need a textbook, you probably come to me," she said. "If you want to know about the curriculum, you probably go to him. It's very comfortable, and the teachers seem to appreciate both our roles."

Coppels said it is not only work that is comfortable. After "some initial adjustment" for his stepchildren, who found living in Purcellville rather different than living in New Orleans, he said, his family has not looked back.

His wife works a little closer to home than he does, teaching at Cool Spring Elementary in Leesburg.

"Going home, coming up out of Leesburg into the mountains, the tensions of the day just drain out of you," Coppels said.

He remembers telling Cool Spring Principal Evelyn Collier how glad he was to be in Loudoun, "and she said, 'Preston, your soul has been here all the time. It was just waiting for your body to arrive.' "

After a year, Coppels said his chief surprise was the fluctuation in the number of Algonkian students, which dwindled to 660 from a high of 673, as mobile families moved away.

He is losing two teachers this summer, both because their husbands have been transferred and not because they want to go.

"This is a neat school," said third-grade teacher Meg Chow, who took a sabbatical from teaching to raise her family and said she was uncertain whether she would return to the classroom last year until she met Coppels. "I decided during the interview. I said, you're never going to get another one like that . . . . The teachers are happy, the children are happy. I know it sounds corny, but you like to come to school."

Her third-graders generally confirmed that view (John Kilmer said he liked science class this year, Jessica Diaz said she liked art and Erica Fielding said she liked Mrs. Chow).

But on June 13, the children at Algonkian were very much taken with the idea of leaving school.

Their classrooms had been turned into confectionaries -- desks heaped with bowls of ice cream, sundae fixings, cookies and chips -- and games replaced textbooks on the last day.

Somehow, in mid-pandemonium, report cards were distributed, final instructions given, songs sung, goodbyes said.

For the grownups, there would be a breakfast the following morning to thank the school staff, and a pot luck lunch shared among the teachers.

But for the children, who exploded from the building promptly at 2:45 p.m., there was no tomorrow. Only summer.