What do you do when your writing career lasts seven decades but you haven’t said everything you once thought about saying? If you’re John McPhee, you crack open your notebooks and give fans a taste of the stories you never wrote.

That’s the premise behind “Tabula Rasa,” which the 92-year-old McPhee wryly indicates is “Volume 1” because “the purpose of (the project) is to keep the old writer alive by never coming to an end.”

There are plenty of snippets here that will make readers wish McPhee had indeed delved deeper into particular topics. A longer profile of fellow writer Edward Abbey would have been nice after hearing him recount the stoning of a rabbit at a Princeton colloquium. Or more color from a 1979 Independence Day fireworks party aboard Malcolm Forbes’ yacht in New York’s East River.

Some of the best writing in this collection could be considered memoir — from McPhee’s high school job as a billy club- and flashlight-toting night watchman at the Institute for Advanced Study in Princeton, to finding one-sentence and three-page autobiographies written by his late parents among their possessions.

Most of the writing is no more than vignettes, as in “Back up the Riverbank,” which lists the 19 species of fish McPhee has caught on the Delaware River. He chose to write about only one, the American shad, in his book “The Founding Fish.”

“Tabula Rasa” demonstrates just how broad McPhee’s “tabula” has always been. He’s like an NBA star who always has the green light to shoot. His career as a contributor and staff writer at the New Yorker, begun in 1963 and still going, allows him to pitch editors on topics that interest him, then travel to where those stories are. Sometimes even after all that effort, the words never get published, and we’re left with the mere promise of a longer piece, as in the essay called “Beelining”: “The longest beeline distance in the forty-eight contiguous United States runs from Bellingham, Washington, to Boca Raton, Florida, two thousand seven hundred miles and change.”

I don’t know about you, but I’d buy a McPhee book featuring the characters he’d meet along the way. Instead, all we can do is wait for “Volume 2.”