For nine days Bob Speca Jr., 21, crawled around the Manhattan Center ballroom on his hands and knees, setting up dominoes. He suspected cockroaches of slithering out at night and knocking some of them over. But finally the University of Pennsylvania senior had built a Rube Goldberg maze of 100,000 of the little rectangles. It featured ramps, slides and words (the names of his girlfriend and swimming coach, for example)—and Bob was all set to break his own record for nonstop domino toppling.

The show, a fund-raising promotion by the National Hemophilia Foundation, got under way when 8-year-old hemophiliac Michael Murphy provided the initial push. But as the dominoes began to fall with a soft whoosh, an ABC-TV cameraman leaned over the ballroom balcony and dropped his press card, accidentally triggering a second chain reaction on the opposite side of the room. ("I feel terrible," groaned photographer Manny Alpert later.) Speca stepped quickly through the labyrinth, however, pushed a few of the dominoes aside and isolated the damage. Thirty-one minutes and 20 seconds after the start, Speca had a new record of 97,500 dominoes (his old one: 50,000).

Speca's friends "thought it was crazy" when he began his strange hobby in his family's Broomall, Pa. basement five years ago. Since then, however, he has made two network TV appearances and earned up to 90¢ per domino as an attraction at restaurant and shopping mall openings. Dominoes otherwise hold little attraction. "I never play the game," Speca says. "It's not too interesting." He thinks of his avocation as an art form and objects to being called "eccentric." "If I set them up without any clothes on, that would be eccentric. Right?"