Next to Garbo, Buster Keaton possessed the most exquisite face in the history of the movies. White as alabaster, with dark, shy, feline eyes and high, finely sculpted cheekbones, it was capable of a vast range of expression, from the open inquisitiveness of a child to the worldly nonchalance of a millionaire playboy. At the same time, its beauty is as distant and inscrutable as the lunar surface; it suggests isolation, loneliness, perhaps even despair. Of all the silent comics, he was the most silent.

Like Mack Sennett before him, Keaton understood that film is action, and he shared with most Americans a love of speed. Perhaps better than any others, his movies capture the tumultuous, headlong spirit of his time. Yet somehow, no other figure in film seems as motionless, as enduringly still. Keaton is a unique figure not just in the history of film, but in the whole, long American parade. As a rule, we prefer our heroes to be accessible, gregarious, larger than life. Not so Buster Keaton, whose centennial this month has been commemorated by a spectacular 30-film boxed set by Kino Video. Amid the tumult, Keaton stands alone, silent and imperturbable, the calm, impassive eye of the 20th-century hurricane.

Unlike Charlie Chaplin, his contemporary and rival, Keaton never asks for our sympathy or approval. In fact, it is very seldom that he asks anything of us emotionally. What he wants is laughs, pure and simple.

Whether he is sitting placidly on the cowcatcher of a train hurtling full-speed toward the camera, as he is in "The Goat" (1921), or pacing up and down the spine of a dinosaur, as he did in "Three Ages" (1923), Keaton maintains the same mask of neutrality. At times, his intractability could get him -- or, rather, his characters -- into trouble. In "Go West" (1925), Keaton accuses one of his opponents in a poker game of dealing off the bottom of the deck. Outraged, the man pulls a gun on Keaton and growls, "When you say that, smile." Try though he might, however, the Great Stone Face can't work up a grin -- even at gunpoint -- forcing him to parody the tragic Lillian Gish in "Broken Blossoms" by using his fingers to push up the corners of his mouth.

Keaton never pursued the sentimental or the poetic; he never got icky. Instead, there is a kind of mathematical purity to his films. "The General" (1927) -- Keaton's own favorite and usually touted as his masterpiece -- is justly praised for its expansive depiction of the antebellum South; "Three Ages," Keaton's droll parody of D.W. Griffith's 1916 epic "Intolerance," stands out for its attention to period detail; and "Go West" is remembered for its ravishing Western landscapes. But what is immediately striking about these movies is their expert sense of design and execution.

Keaton's films are like elaborate laboratories set up for research into the physics of slapstick. When he titled his autobiography "My Wonderful World of Slapstick," it was meant both ironically -- it was often far from wonderful -- and literally. Keaton's world was slapstick. He was a diligent student of what made people laugh, and he took a mechanic's delight in the construction of gags. This is what drives Keaton's movies -- the mechanics of the gag.

When critics rediscovered him in the '50s and, making comparisons to Sartre and Beckett, suggested that his work was that of a serious artist, Keaton immediately dismissed the notion, saying, "No man can be a genius in slap shoes and a flat hat."

Despite their creator's own disclaimers, Keaton's movies are never merely a string of gags. Nor can they be evaluated in terms of story or theme. Keaton's greatness lies in the spareness and simplicity of his vision and the consistency of his worldview.

To Keaton, nothing is to be trusted, not even the laws of physics. Nor can one rely on one's senses and perceptions. All in all, life in Keaton's movies is a fairly precarious, if not grim, proposition. If on occasion he allowed himself to triumph, more often than not he was the butt of some enormous joke that life was playing on him. He was, in short, a classic fool.

The details of young Buster's early life are famously unreliable, a mixture of show-biz hyperbole and western tall tale. Joseph Francis "Buster" Keaton was born in Piqua, Kan., on Oct. 4, 1895. Buster's mother, Myra, was the daughter of Frank Cutler, who during the late 1890s produced and managed a number of medicine shows traveling through what was known then as the "Old Wild West." Her specialty was the saxophone. His father, Joseph, was a jack of all comic trades -- dancer, acrobat, slapstick comic, actor -- not to mention a shrewd and imaginative publicity man.

Though Keaton is said to have "crawled" into his family vaudeville act as early as the age of 9 months, he didn't officially join the act until the ripe old age of 2. Keaton was a child star on the vaudeville stage long before moving to film. By age 6, he had traveled the country playing the Orpheum circuit. A year later reviewers were already referring to the two older members of "The Three Keatons" as a distraction from the stellar baby Buster.

The act evolved over the years. Initially, as Keaton later described it, his job was to "get in my father's way all the time and get kicked all over the stage." Eventually, their routines developed into what Keaton biographer Tom Dardis calls a "unique kind of improvised physical exchange between Buster and his father, a roughhouse dialogue involving a breathtaking series of violent encounters in which Buster either hit his father or was hit by him."

It was during these sessions that Keaton learned the comic fundamentals that he would call on -- and masterfully expand on -- in his later film work. It was also where he developed his magnificent deadpan. "In order to make this funny,' " Dardis writes, "Buster had to secure some sort of comic mask to prevent his audience from thinking that the rough treatment hurt him. This mask became the grave face that never smiles, Buster Keaton's identifying mark as a performer for the next sixty years."

Keaton himself gave a different account. "In this knockabout act, my father and I used to hit each other," he wrote in an article titled "Why I Never Smile." "If I should chance to smile, the next hit would be a good deal harder."

Keaton's introduction to motion pictures came when he traveled to New York to join the cast of "The Passing Show of 1917" on Broadway. While waiting for rehearsals to begin, Keaton ran into his old friend Roscoe "Fatty" Arbuckle, who was beginning to make two-reelers in an old East Side loft. Arbuckle himself had been the main star at Keystone until producer Joseph Schenck enabled him to establish a company of his own. The studio would give Keaton his first chance as a screen comedian that very first day when Arbuckle asked Buster to join them in shooting a bit for a two-reeler called "The Butcher Boy." By the end of the day, Keaton knew exactly where his future lay. He arranged for his Broadway contract to be torn up and plunged headlong into film work with Arbuckle.

From the beginning, Keaton's movies were highly ingenious mechanized feats, laid out with the precision of a geometry problem. "The High Sign" (1921) was the first of the shorts Keaton made without Arbuckle, and while as a whole it is an inferior work, it immediately demonstrates the sort of film artist he was going to be.

The fully articulated Keaton persona makes his first entrance here, characteristically landing on the seat of his pants after being hurled from a fireballing locomotive. As the opening title card tells us: "Our Hero came from Nowhere -- He wasn't going Anywhere and got kicked off Somewhere."

Already the signature porkpie hat is in place, steady above the implacable face and the short, pistonlike arms and legs. And a native surrealism is visible. In one scene, the protagonist arrives at his new job as a sharpshooter at a carnival arcade, and, unable to find a place to hang his hat, picks up a brush and paints a hook on the wall.

Later, in yet another nod to the surreal, Keaton finds himself trapped in a room without any apparent escape, only to invent one by diving headlong into the surf in the painting on the wall. Keaton's great period of blossoming was short, lasting only the eight glorious, hectic years between 1920 and 1928. During that time, he produced the 19 two-reelers and 10 feature-length films on which his reputation is largely based. During that brief interval, the former child star helped to define the language of film comedy. But Keaton's impassive face may have been a more accurate mirror of the comic's personality than has been fully understood.

Off screen, he was trapped in a loveless marriage to Natalie Talmadge, the sister of Constance and Norma, two of Hollywood's biggest silent stars. As a result, he retreated into work, or cards, or the bottle -- which was fine as long as there was work. But the disappointing reception to his beloved "The General" was followed by falling box office receipts from both "College" (1927) and "Steamboat Bill Jr." (1928).

Then, in 1928, a year after Al Jolson's "The Jazz Singer" ushered in the Sound Era, Schenck announced that he was dismantling Buster Keaton Productions and turning Keaton over to MGM and its assembly-line approach. The move represented a catastrophe for Keaton.

"The Cameraman," which he completed for MGM in 1928, would be the last film the comedian would make with anything like the creative control he enjoyed during his heyday. The industry was shifting over to sound as rapidly as possible. As Keaton biographer Marion Meade writes, "On Christmas Eve 1928, Keaton completed Spite Marriage,' his last silent feature. . . . It would be almost a year before he would begin his next picture."

Buster Keaton lasted at MGM until February 1933, when Louis B. Mayer grew fed up with the reckless star's drunkenness and frequent absences and canceled his contract. By that time, Natalie had already sued him for divorce, taking their boys, Jimmy and Bobby, with her. Keaton kept busy; in fact, he worked consistently until his death, on everything from game shows to commercials to the circus. But the once-beautiful face began to show traces of the battles he fought with alcohol and depression. He made a notable but enigmatic appearance as one of "the waxworks" in Billy Wilder's "Sunset Boulevard" (1950), and showed up in "Around the World in 80 Days" (1956), "It's a Mad, Mad, Mad, Mad World" (1963) and a string of teen beach pictures, including "Beach Blanket Bingo" (1965) and "How to Stuff a Wild Bikini" (1965).

The best of these later appearances came in Chaplin's "Limelight" (1952). Though Keaton doesn't play a central role, he has a scene with Chaplin that is by far the brightest spot in an otherwise glum affair. His last so-called "serious" work came in 1965, in Alan Schneider's adaptation of Samuel Beckett's first screenplay, "Film." By any measure, the movie is stupendously abstruse and pretentious. Yet somehow, by laboring so strenuously to create the absurdist dimension that the silent comedian had evoked so effortlessly in his films, it seems almost the perfect culmination of Keaton's work.

Keaton died on Feb. 1, 1966. His wife, Eleanor -- whom he had married in May 1940 -- honored the comedian's final request by placing a rosary in one of his pockets and a deck of cards in the other. That way, he'd told her, whichever direction he went, he'd be prepared. CAPTION: Poker-face Buster Keaton in "The Three Ages," top left; "The General," above; "The Electric House," left; and "Go West."