"It takes some courage to show Julia Child how to chop an onion," New York Times food editor Craig Claiborne told an audience that included Julia Child last night at a cooking demonstration to benefit Radcliffe's Schlesinger Library.

The demonstration, which drew 500 people, was a benefit to match a $400,000 challenge grant awarded to the Schlesinger Library by the National Endowment for the Humanities, raised at least $10,000, Patricia King, director of the Schlesinger Library, said last night.

King said she was not sure how Radcliffe would raise the remaining money. "We will have other events, but nothing quite on this scale is planned at the moment," she said.

Claiborne's associate, Pierre Franey, demonstrated nine recipes as Claiborne described technique and injected anecdotes.

All the members of the audience received a booklet containing the demonstrated recipes and excerpts from several of the 2300 volumes in the Schlesinger Library culinary collection.

Boston radio announcer Carl deSuze auctioned cooking utensils used by Claiborne and Franey after the demonstration, along with the prepared food. The utensils had been donated to Radcliffe, College.

Claiborne chose seafood recipes because his assistant Franey is "the greatest fish cook in the country," and because "a lot of people like fish but don't know how to cook it," he said.

Along with Mousse of Scallops, Poached Striped Bass, and Soupe de Poisson, the pair prepared a Sauce Gribiche, a variation on mayonnaise which contains mustard. "If you use the old-fashioned ball-park mustard, you get something that tastes like a church supper," Claiborne said.

After burning one recipe, Claiborne said, "Sarah Bernhardt fell flat on her face." Earlier he had said of his Science Center surroundings, "There's no place like home, I'll tell you."