LATE AFTERNOON, Oct. 19, 1899, Worcester, Mass. Seventy-four days left in the 19th century. The air was sharp, cold in the nostrils, sweet with the smell of apples and leafsmoke. Robert H. Goddard, aged 17, climbed a homemade ladder to prune a cherry tree. High in the air, he gazed out across the pastures for a long, long time.

Everything seemed so different, laid out beneath him. How would the earth look from far up in the clouds? From the moon? From another planet? How could a man put himself up there?

He balanced on the top branches, lost in his daydream, a boy's fantasy of a spinning projectile that could take him beyond the sky.

"I was a different boy when I descended the tree from which I ascended," he wrote later. "Existence at last seemed very purposive."

A diffident statement, awkward and stiffly formal, yet confiding, somehow. But that was Robert Goddard.

Behind the story of the visionary rocket pioneer -- who was born 100 years ago Oct. 5 -- lies the story of a man so unconcerned with self-promotion that the world had to discover his greatness on its own time.

In the final days of World War II, Wernher von Braun and the other German scientists who had developed the V2 long-range ballistic missile for the Nazis at Peenemu nde came over to the Americans. The first thing Army intelligence officers said to them was: Tell us about the German rockets.

Von Braun said, Well, of course, we learned the principles from your Dr. Goddard. The V2 rocket is essentially the same thing he sent up in 1939.

Who? the Army said.

They had barely heard of him.

This was the man who had actually demonstrated to the Army what was in essence the bazooka, a key anti-tank weapon of World War II. Unfortunately, he had demonstrated it while World War I was still going on, and the Army wasn't interested. It would take the military another 25 years to grasp its value. His 214 patents included an oscillator that anticipated the radio tube. His basic rocket patent was dated 1914.

Goddard's earliest major recognition came from a 1919 paper, "A Method of Reaching Extreme Altitudes," suggesting a multistage rocket that would fly a payload to the moon. The New York Times chuckled patronizingly that Goddard lacked "the knowledge ladled out daily in our high schools."

Forty-nine years later, as Apollo II homed in on the moon, the newspaper printed one of the great retractions of our time:

"It is now definitely established that a rocket can function in a vacuum. The Times regrets the error."

A few years ago the Smithsonian Institution, his first and for years his only backer, revealed that Goddard had written four other papers in the early '20s. They discussed electron and ion rocket engines, liquid oxygen and hydrogen as fuels, gyro-stabilization, space probes, flight-path correction techniques, solar propulsion and even reentry heat shields. He also designed a half-ton crew compartment for his rocket.

It wasn't until 1960 that the U.S. government admitted it had infringed on the inventor's patents for the Atlas, Jupiter, Redstone, Thor and Vanguard rocket engines and paid his widow a million dollars. She gave half to the Daniel and Florence Guggenheim Foundation, which had backed Goddard from 1930 on.

A modest man, even on the greatest day of his life . . .

March 16, 1926: A crisp, freezing afternoon with an inch of snow on the ground outside his aunt Effie Ward's farmhouse at Auburn, Mass. Goddard, his young wife Esther, his machinist friend Henry Sachs and Percy Roope, a colleague in the physics department at Clark University in Worcester, drank a last cup of hot malted milk and went outside, bundled to the ears. It was 2:30 p.m.

It had taken all morning to assemble the flimsy 10-foot-high apparatus of steel pipe and tubing. On top was the cylindrical motor, two feet long and attached by separate oxygen and gasoline hoses to the rocket-shaped fuel tank below it. Goddard let in oxygen from a nearby cylinder. Then Sachs lit a blowtorch, stuck it on a pole and reached up to touch off the black-powder igniter at the very top.

It flared and roared. For 10 seconds nothing moved. At last it stirred, lifted, cleared the frame, gaining speed faster than the eye could comprehend. Forty-one feet straight up . . . It faltered, curved, swooped down still roaring to hit the ground 184 feet away.

Robert Goddard had just launched the space age.

"He didn't say much," his wife recalled years later, "but you ask any inventor about his invention when it works for the first time, and there's just nothing like it."

Roope said, "He was calm, he always was quiet and cool. But you could tell he was really excited. He flushed up a bit . . ."

They went back to the kitchen for some coffee and talk. Later they came out and collected all the pieces. The repaired rocket was to fly again two weeks later.

Mrs. Goddard made a movie of the 2 1/2-second flight, but the seven seconds worth of film ran out before the thing took off. She did take some photographs, however, which still appear like a talisman in all the histories of space flight. They show Goddard, in his flat cap and high-buttoned overcoat and galoshes, standing by his creation in the snow and then looking up at the empty frame. He seems to be grinning.

In his diary he reported that "it looked almost magical as it rose, without any appreciably greater noise or flame, as if it said, 'I've been here long enough, I think I'll be going somewhere else, if you don't mind.' Esther said that it looked like a fairy or an aesthetic dancer as it started off."

This was the same diary in which he had written, in 1906, "Decided today that space navigation is a physical impossibility," and in 1908, "God pity a one-dream man."

In 1912, a year after taking his doctorate in physics at Clark, he got a research fellowship at Princeton (didn't dare tell them he wanted to do rockets; worked instead on his radio tube oscillator), and a few months later, exhausted from working nights on his dream, was told he had tuberculosis and would die in two weeks. But he recovered and returned to Clark. It must have seemed a retreat at the time.

At least he could concentrate on his real work there, where people let him do what he wanted, and understood him. And loved him. He was an exciting teacher. When a lab demonstration went well, he would absently whistle "It's a Long Way to Tipperary" and the class would cheer. He got his graduate students to help him, cajoled local machinists into building his intricate mechanisms, mesmerized an industrial lab into testing his gunpowder mixtures. ("We ran off his test, not knowing what he was up to, but feeling sure he did," the owner said.)

Even then, he had to tell most people he was working on a rocket for atmospheric studies. He just couldn't give them that stuff about the moon. He learned to keep away from the press, which had laughed up its sleeve at him: "the moon-rocket man." Other scientists often found him secretive, suspicious of sharing his discoveries.

In 1929 he sent up a rocket with instruments aboard. Neighbors thought it was a plane crash, and Aunt Effie's farm swarmed with ambulances, police and reporters. The tests were banned. He fired his rockets at nearby Fort Devens, finally moved to Roswell, N.M., where he could work in privacy with his Guggenheim grant. When the money stopped temporarily in the Depression he returned to Clark to teach again. But he never quit tinkering, puzzling, calculating. In '35 he built a rocket that passed the speed of sound. Another rose 9,000 feet. Slowly, with constant disappointment and frustration, he gained ground.

In Roswell, worried over increasing foreign expertise in rocketry, he worked harder than ever. Esther (who died this June) got him to relax a bit, and he even joined Rotary. His friends called him Bob and proclaimed him "plain as blueberry pie," a man who laughed easily, smoked his cigars down to the nub and loved Buster Keaton movies. He painted landscapes and sometimes startled people by singing pop songs he had heard on the radio, and on July Fourth he could be counted on to set off some rockets for the kids. But always, deep inside him, was that other person, that solitary one, silent and intent.

Two months before Pearl Harbor, he offered his work to the American military. They saw no use for rocket missiles. They set him to developing takeoff-assisting rocket motors. He was so bored he wrote short stories in his spare time. He died five days before V-J Day in 1945, in Baltimore. He was not quite 63.

Someone found among his things an envelope containing an essay, "The Last Migration," envisioning a day when the human race would have to flee a dying solar system and fly in their spaceships to another galaxy.

The rest of the world was always trying to catch up with Robert Goddard. Nearly two-thirds of his patents were granted him after his death, from his notebooks. It would be another 16 years before a man finally got to see what the earth looked like from the end of gravity's tether. It is probably just as well that Goddard never knew the first man in space was a Russian.

On Oct. 4, the world will celebrate the 25th anniversary of Sputnik, the first orbiting artificial satellite, also Russian.

But at Clark University, the main celebration will start one day later: Goddard's 100th birthday. It will go on for three days, and NASA will send a model of the space shuttle, and area industries will show space wares, and a memorial service will be held for Esther, who became widely known in the astronautics world in later years, and the government has promised to dispatch a live Columbia astronaut to the scene.

The most exciting event surely will be the re-creation of that first liftoff -- on the golf course that used to be Aunt Effie's farm. That should be the best-attended of all. Maybe it will be a bit like the old days when he would be getting ready to shoot a rocket and the woods surrounding the farm would be just full of bug-eyed small boys.

Goddard may be a legend now, but around Worcester he is still a hometown kid. The university people refer to him as "the late Clark physics professor and rocket pioneer," and during all those years in Roswell, and even at the end, when he worked for the Navy at Baltimore, he was officially a teacher on leave from the university, and that was how he described himself.

But then, Robert Goddard never did need trappings. His dreams were grandeur enough.