Buster and Joe discovered that when he was hurled through the bass drum and emerged waving and smiling, the audience didn't see the joke in treating a kid that way. But when Buster emerged with a solemn expression on his face, for some reason the audience loved it. For the rest of his career, Keaton was "the great stone face," with an expression that ranged from the impassive to the slightly quizzical.

He falls and falls and falls in his movies: From second-story windows, cliffs, trees, trains, motorcycles, balconies. The falls are usually not faked: He lands, gets up, keep going. He was one of the most gifted stuntmen in the movies. Even when there is fakery, the result is daring; in "Go West" he seems to fall from a high suspension bridge, but actually falls only 50 feet or so before landing in a net; there's a cut to another shot showing him falling the last 20 feet. Both halves of this "faked" stunt are dangerous. And in "Our Hospitality," where he was almost killed when a safety wire snapped and he was swept toward a waterfall, he finished the sequence with a fake waterfall--but even it was 25 feet high, and he's swinging above a nasty fall.

Keaton is famous for a shot in "Steamboat Bill, Jr.," where he stands in front of a house during a cyclone, and a wall falls on top of him; he is saved because he happens to be exactly where the window is. There was scant clearance on either side, and you can see his shoulders tighten a little just as the wall lands. He refused to rehearse the stunt because, he explained, he trusted his set-up, so why waste a wall?

In film after film, Keaton does difficult and dangerous things and keeps the poker face. His philosophy is embodied in his body language: The world throws its worst at him, but he is plucky and determined, ingenious and stubborn, and will do his best. Walter Kerr, in his definitive book "The Silent Clowns," writes of Keaton's "stillness of emotion as well as body, a universal stillness that comes of things functioining well, of having achieved harmony." When Harold Lloyd dangled from a clock face far above the street, he intended to terrify his audience. When Keaton sat on the front of a moving locomotive in "The General" and attempted to knock one railroad tie off the tracks with another, he could have been crushed beneath the train, but he presents the action as a strategy, not a stunt.

Kerr talks of the "Keaton Curve," the way an action ends up where it began. There's a shot in the early short "Neighbors" where Keaton escapes a house via a clothesline, swings safely across to his own house--then finds that the clothesline keeps rotating, depositing him right back in trouble. In "The General," there are innumerable examples of the Curve, for example a scene where the train goes around a bend so that a cannon now points at Buster instead of the enemy. You can also see the Curve in many of those scenes where he invents ingenious "labor-saving" devices--to serve breaskfast, for example. One of his funniest shorts is "The Scarecrow," which includes a house where everything--table, bed, stove--has more than one function, so that a meal consists of a tour through the parabola of the house's gadgets.