A chair apart - being seated personally by Jimmy Carter

A New Yorker cartoon presents a well-dressed woman in a small tidy store with a sign in the window: ''Arts, Antiques, Appraisals.'' The proprietor addresses his customer as she stands before him, slightly affronted, with a protective hand on the back of a cane-bottomed chair: ''If it makes you feel any better, Madam, in our opinion, you have purchased one of the first fake Jimmy Carters.''

Well, it was bound to happen. The former president is a hard worker - we all know that. But a man can produce only so many chairs himself, what with making appearances in the company of Gerald Ford to straighten out President Reagan on foreign policy.

And if the duties of statesman have cut back on Georgia's most prestigious article of furniture, we can only imagine what has happened to Mr. Ford's golf game.

Despite the risks of forgery, it seems like a good idea that Mr. Carter should be turning his hand to furniture. Four chairs to start with, and surely more to come. We thought seriously of placing an order. Mr. Carter was always a meticulous man with details - to a fault, his critics said. You could bet he would not delegate the gluing or sanding to a subordinate. Everything would be tight. Everything would fit. All four legs would touch the floor, and if they didn't, it would be because Jimmy Carter hadn't laid your floor.

We're not so sure we'd buy a Ford or Nixon chair. Mr. Nixon, with all due respect, never appeared to know what to do with his hands as a public speaker, and we're not at all confident the solution would be to put a saw or a rasp in them.

Mr. Ford has a keen eye, a deliberate manner, and a background in Grand Rapids, a furniture city if there ever was one. But there's something amiably distracted about the man. If anybody interrupted him halfway through a job or he started telling one of his favorite jokes, we'd worry about the dowels.

If we were to pick a Republican to craft a chair for us, it might be Barry Goldwater. Your uncle who loves his chocolate creams could sit safely in a Barry Goldwater chair. Solid! Four-square!

Just to spread the trade around, perhaps Senator Goldwater could build desks when he retires - sturdy rolltop editions, like those that Arizona railroad agents used to sit at years ago. A free green eyeshade if you pay with cash.

''Tip'' O'Neill might specialize in Boston rockers after he steps down. But the Speaker of the House strikes us as too gregarious to retire to the solitude of his basement and throw a pal's arm, as it were, around his old workbench.

This brings us to the whole difficult question of retirement at the top. Somebody ought to conduct a study of what men with power do to pass the time after they've suddenly run out of power. The tricky adjustment must be a bit like that of a soldier returning from war. After all the fire, after all the smoke, after all the chaos and action, how does one settle down, in a shaft of sunlight and sawdust, to the peace of whittling away at a block of fine-grained wood?

We can understand why Mr. Carter wants to keep one hand on the power tools of politics, so to speak, particularly during an election year. But we're glad the other hand is whittling. The fact is, we were never completely comfortable with Mr. Carter as a man of power, trying so resolutely to look resolute.

Mr. Carter, the populist farmer with baggy sweater, may have been partially a political creation. But Mr. Carter, the chairmaker, convinces us that it was more than a pose. You can't build a chair by smiling folksily at a hunk of hickory.

Every man-of-power has to hide a man-out-of-power within him or else he would be a monster.

Churchill became a landscape painter. Mickey Walker became a better one. His paintings sold because they were good, not because they were his. Mickey had been a middle-weight boxing champion. ''The Toy Bulldog'' was his nickname. But when Mickey, with his gnarled hands and flattened nose, stood proudly - and gently - beside one of his paintings, you felt that a man-of-power had become what he was meant to be.

Perhaps Mr. Carter will be remembered for being President. It's a hard act to follow. But who can say? We certainly can't. We still haven't seen one of the authentic chairs.