If you happened to miss Johnny Carson's debut as host of "The Tonight Show" on Oct. 1, 1962, you'll never see it now. Not even if you have a houseful of VCRs. The program is just one of thousands of movies and television shows recorded on perishable film, and lost forever.

Today, the National Endowment for the Arts and the American Film Institute announced the establishment of the Center for Film and Video Preservation. NEA chairman Frank Hodsoll, in announcing that the endowment has committed $279,000 to the new center, said that "preservation of film and video is a primary concern of the endowment . . . Two hundred years from now, the best of the moving images from this century simply have to be around for future Americans. That's why we're in it."

Screenwriter Fay Kanin, a past president of the Academy of Motion Picture Arts and Sciences, actor Eddie Albert and Elton Rule, former president of the American Broadcasting Co., are cochairs of the 32-member advisory board that will administer the center.

Kanin noted that before the 1950s almost all films were shot on highly perishable, and highly flammable, nitrate film. "We all like to say that a great film will last forever," Kanin said. "But the fact is that the physical material doesn't. Nitrate film turns to goo -- if it doesn't burn first."

About half of all the films made before 1950 no longer exist in any form. Among the thousands of perished movies are the 1917 version of "Cleopatra," starring Theda Bara; "That Royale Girl," a 1925 movie directed by D.W. Griffith and starring W.C. Fields; and "The Matinee Idol," one of the early works of legendary director Frank Capra.

There are also many television productions from the 1950s, known as TV's "golden era," that are believed not to have survived. They include the Studio One presentation of "Twelve Angry Men," and part two of "The Petrified Forest," which starred Humphrey Bogart, Lauren Bacall and Henry Fonda.

The center hopes to have movies that were shot on nitrate-based film copied onto acetate safety film.

Board members said today that the aims of the new center include the creation of a computerized log of all film, television and video holdings now in the possession of archives, museums and producers, and the establishment of criteria for what needs to be saved. They are asking producers to impose a voluntary two-year moratorium on the destruction of any film, while they establish guidelines for preservation.

Not long ago, Hodsoll added, "We had the museums and archives on one side, and the entertainment industry on the other side. And each side was suspicious of the other." But at today's first board meeting, the NEA chairman said, the various factions "were more cooperative than I had expected. I think the time is right."

Board members include Daniel Boorstin, the Librarian of Congress; Jack Valenti, president of the Motion Picture Association of America; director Martin Scorsese; Richard Oldenburg, director of the Museum of Modern Art; Barry Diller, chairman of 20th Century-Fox; Frank Mancuso, chairman of Paramount Pictures; Lee Rich, president of Lorimar; Frank Wells, president of Walt Disney Productions; Frank Rothman, chairman of the board of MGM/UA Entertainment Co.; Sid Sheinberg, president of MCA Inc.; NBC chairman Grant Tinker and CBS Broadcast Group president Gene Jankowski.