William Hazlett, essayist and critic of the early 19th century, used to say he'd rather walk alone. For one thing, he figured conversation might lead to an argument and "I never quarrel with myself."

Jack Glass, a budget analyst with NIH, thinks Hazlett should have given his collegues more of a chance. "Ever since I've been walking," Glass said yesterday while out for a walk, "I've never had an incident that's been unpleasant." He said this while surrounded by walkers.

Yesterday was the Cherry Blossom walk, not to be confused with the Cherry Blossom run. This more civil way of getting about the city was shared by 22 men and women, including an 81-year-old man who has walked the entire 2,000-mile Appalachian Trail in his day and a 39-year-old man who has decided it's time he exercised and jogging is not for him.

It mattered not that the cherry blossoms had yet to bloom. What counted most for this largely 40 to 81 age group were the fresh air, the exercise, the spiritual uplift, the sightseeing, the fun. These not-so-rigorous six miles (plenty of time to rest along the way) were sponsored by the Center Hiking Club, and led by Marilyn DeLoach, who not only pointed out appropriate landmarks, but made certain everyone got across the streets safely.

Walkers can't be too careful. A couple of very famous one have made costly missteps. David Douglas, for whom the Douglas fir is named, fell into an occupied bull pit and was gored to death. Though bull pits don't claim many pedestrians these days, automobiles do. Edward Payson Weston, who walked from Boston to Lincoln's inaurugration, was struck by a speeding taxi in 1927, ending his walking career at the age of 88 and confining him to a wheelchair.

Carl Jones, serving as rear guard yesterday, helped the stragglers across the broad avenues. At 81, Jones, who was wearing a flannel shirt and red windbreaker but no hat despite an occasionally strong wind, says he walks at least four miles a day.

"From the age of 71 to 81," he says, "I haven't been sick once. For that age period, I've done pretty well. I've passed through life happily. My emotional condition is good."

"Walking is the best theraphy," added Margaret Hetrick, a retired government clerk. "It's good for the blues or anything that ails you, and I'm no kidding, I'm telling you truthfully. It's much better for a depression than tranquilizer." Hetrick said her Swiss father walked the Alps (as she did last summer) and that he got her out walkind "when I was 4 years old . . . when I could just raise my feet. It seems the natural thing to do."

Striding close to Jones and trying to learn what he could from him was Stan Gertzman, 39, who said he had been moved to get in shape by the recent outpouring of literature on exercise. The trouble is he doesn't like most exercises.

"I hope this works," he said. "I guess I'm going to have to buy a pair of shoes before I go anywhere else." He was wearing black dress shoes.

As the group moved from the downtown YWCA toward the Lincoln Memorial and on to the Jefferson, it blended with a potpourri of joggers, other walkers, cyclists, sightseers, and some who had run the 10-mile Cherry Blossom classic and were now walking. Thousands were out under a blue sky. A tour bus passed with "Kissinger Travel" written on it.

Brenda Holt, 42, from Staffordshire, England, who recently moved to Washington and works at the World Bank, reminded a companion that "the British do quite a bit of walking." In fact, walking was once a spectator sport in Britain, with heavy betting on or against certain celebrated pedestrians, such as the late George Wilson.He attempted 1,000 miles in 20 successive days in 1815 and - despite bribes and nasty bystanders who stepped on his heels - seemed on the verge of making it (though some days he had to be carried to and from the starting line) when he was arrested on a charge of disturbing the peace.

Miriam Schachter, who works at the Treasury, said she has atracted attention, though she hasn't intended to, by walking 35 blocks to work and 35 blocks home. "'How do you do it?' they all ask," she told another walker. "An hour's walk, and I'm a celebrity."

Knowing the joys of walking, others laughed. Irving Javins, 66, has come from the country to walk in the city.A farmer in Front Royal, Va., Jarvins, wearing a carnation in his lapel, said walking "gives me a better appetite, I rest better, it gives me the chance for sightseeing, it gets me away from where I live so I can meet new people."

"You get the fellowship," said Hetrick, offering an acquaintance hot tea from her thermos during lunch at the Jefferson Memorial before a swing around Hains Point and back to 16th and K Streets. Passing some fishermen at the Tidal Basin, the newcomer Stan Gertzman said, "That's another thing I don't like to do. It's amazing the things I don't like to do."

But he said he thought he was going to like this business of walking. He wasn't even breathing hard.