At about 5 p.m. Tuesday, as the classes of '42 and '57 filed onto buses en route to the Boston Pops, reunion headquarters were bustling as usual. It was only the middle of the day for reunion staffers, who work from 7 a.m. to well after midnight every day this week.

Next day, same time, 25th reunion coordinator Marion R. Briefer complained that she was "sort of brain-dead," while 50th and 35 the reunion coordinator Jessica A. Barry pronounced herself "totally burnt out of my mind...fried."

Every year at Commencement time, dozens of alumni descend on the banks of the Charles for a week of green grass, bright tents and reunion symposia. And when the alumni arrive the University rolls out the red carpet and all the little perks.

Barry coordinates a 50th reunion staff that includes two student coordinators, four drivers for regular vans, two drivers for handicapped-accessible vans and eight bellhops. That's not counting the "liquor crew" or the bartenders. Or the corps that sets up the sheets and changes the linens.

During reunion week, Harvard becomes a lot like a hotel...with extra-long twin beds.

Over the 18 years that Briefer ahs worked at Harvard, reunions have become a colossal, high-tech operation. When she first came here, she recalls, alumni checked in by signing ledgers. Now, registration is computerized.

And in the past, the reunion committee didn't rent cellular phones to alumni. The phones, Briefer says, are recommended for families with small children--another new development for the 25th reunion class.

"We never sued to have kids under six," Briefer said. "Now we have little infants and toddlers."

Each day is packed with trips and activities for alumni kids. Briefer said parents and children share breakfast but separate for the rest of the day. "When the parents come home at night, I guess they tuck them in," she said.

The Class of '42, too, was well cared for. Nancy Penson, for one, was amazed.

"They gave us everything but drinking glasses," she said, running through the list: towels, washcloths, plastic raincoats, hangers, desk lamps, light bulbs.

"This tie," added her husband, John G. Penson '42, holding up his prize.

In addition, says reunion worker Joe Mullin '95, Harvard gave out tote bags and men's and women's hats.

The paper wastebaskets--specially printed for the Class of '42--were donated by a classmate.

Eugene R. Kirkham '67 provided 45 cases of wine for his class from his California vineyard.

And William Bahary '57 donated 1200 bars of Dove soap to his classmates, delivered with compliments to the class in a Harvard Dining Services bag, according to reunion staffer Joseph Mullin '95.

Geoffrey T. Chalmers '57 painted a picture, "Fair Harvard," which was printed in poster form and distributed to 35th reunion alums. The poster also contains the names of every member of the class of '57--"even the people who are dead," Mullin said.