BRIAN BROWN IS lean and steady-eyed, looks like the late-night television detective, Sam McCloud. That's okay, because Brown is the police chief of Antrim, a small town in southern New Hampshire which I know and love well.

Brian Brown was at the door of the gymnasium of the elementary school the day of Antrim's annual town meeting, closely watch ing the proceedings and helping out in small ways. I speak of him because he is the first public man I have ever heard who said he did not need larger quarters to perform his official duties.

The astounding thing happened like this: Article 21 of the town warrant, a resolution to spend $14,000 to restore the Old Fire Station, proved unexpectedly controversial. Not, I hasten to add, as charged an issue as Article 10, which related to Antrim's adoption of a warship by the same name and resulted in the wonderful spectacle of two townspeople hurling their genealogies at each other, in an attempt to prove in one case that it was not unpatriotic to oppose the adoption, and in the other that it was. Nor, I can tell you, was Article 21 as provocative as Article 30, the nuclear freeze proposal of which Ronald Reagan so vehemently disapproves.

The Old Fire Station resolution touched two sensitive chords in the town's psyche, in that it involved the expenditure of money and its sense of history, and another element which I know from my exposure to the urban form of town meeting -- the condominium assemblies -- stirs more passion than any other: the availability of parking. Inevitably, someone proposed that the Old Fire Station be torn down to make a parking lot, even though that course had been vetoed at last year's town meeting.

The matter was presented by an earnest young man named Geoffrey Goff, who ran into a hail of questions about the need for the building, the possibility of renting the renovated interiors. Goff said that it was possible that the police department could use more space.

"The police department has not said anything about this," said moderator Bob Flanders.

Brown stepped forward and said, amazingly, "Chris (Deputy Police Chief Christopher Joseph) and I think our office is adequate at this time. I cannot justify the use of money or ask you to renovate solely for the police department. We do most of our work on the street or in your houses, which we do not ask you to renovate."

The townspeople seemed to glow at this demonstration of candor and thrift. I was simply stunned.

"There was one time when we were interviewing a juvenile while the planning commission was having a meeting, and there was some interference," this paragon went on, "but that only happens once or twice a year."

Since I have spent much of my life listening to senators and congressmen whining about the hopelessness of conducting their business in anything less than 20-room suites, I was simply floored by the whole episode.

But it was merely for me the high point of the town meeting, which, to tell you the truth, I found the finest political gathering I have ever attended.

I liked everything about it, the good humor, the purposefulness, the way Dorothy Lang, the wife of the postmaster, would fling up her hand to second a motion without missing a stitch in her knitting. I liked the way they swung from the pedestrian to the cosmic without any gear-stripping -- although Nancy Merrifield objected to the inclusion of the freeze because if people have something to say to Washington, "'You write to them and tell them how you feel -- spend 20 cents."

That was not, however, the general sentiment. The people of Antrim believe that at a town meeting you should speak up.

As we went through the long day, from 10 to 5, I fell to thinking what a marvelous invention it was -- "as near to pure democracy as you dare," said Town Clerk Martin Nichols proudly when it was over. It gives people a sense of control over their own destiny -- from repairing the dam at Gregg Lake to giving orders to the White House and the Politburo.

I thought of El Salvador, to which we send guns; of Nicaragua, to which we send covert activity. The town meeting would be better for both. People say this kind of participation requires a long tradition. But if they had a decent weapons-detector at the door, and a moderator like Bob Flanders, who lets everyone speak and only gets mad when children run across the floor in front of him, and a counsel like Lloyd Henderson, who sees that the rules are followed, they could get the hang of it pretty quick -- especially if they understood they wouldn't be shot or jailed for speaking out.

Democracy is a roll of the dice. You take a chance that people will rise above themselves, that any human collection will provide some needed talent.

A town meeting would be a gamble, but who knows? Some Central American village might even turn up the likes of Brian Brown.