Mr. Murphy, a bookish-looking 39-year-old with a fussy bow tie, seems to have been cast for contrast with his rumpled co-editor. His attitude toward garbage is different, too. When asked whether he had ever gone on an excavation, he shuddered. "I thank God I have been spared that," he said. "Frankly, why anyone would do it, even for credit, is beyond me." Steering well clear of the raw material, Mr. Murphy served as editor, researcher and schedule monitor for the foot-dragging Mr. Rathje.

This odd couple of garbology first crossed paths about 10 years ago, when Mr. Murphy, an editor at The Wilson Quarterly, published by the Woodrow Wilson International Center for Scholars in Washington, assigned Mr. Rathje to write some general articles on archaeology. Although Mr. Rathje is identified as a garbage man today, he wrote his undergraduate honors thesis on Tzakol polychrome basal flangeware pottery and did his graduate work at Harvard on classic Mayan civilization. A Book Is Born

After moving to The Atlantic magazine, Mr. Murphy asked Mr. Rathje to write an article about his favorite subject. The resulting article was nominated for a National Magazine Award in 1990 and became a runaway hit for The Atlantic, which eventually ran off 150,000 reprints of it. Because so much material for the article wound up on the cutting-room floor, the two men decided to write a book.

The conclusions of the Garbage Project have pleased and offended business and environmental groups in equal measure. "The fast-food industry and the Styrofoam people have been very pleased with our results," said Mr. Rathje. Environmental groups, whom Mr. Rathe makes a point of inviting on all his excavations, have sometimes had to swallow hard as cherished targets like fast-food packaging have been shown to be minor offenders compared with newspapers and telephone books. But neither side can challenge the Garbage Project's data, for a simple reason. "We're the only group that's systematically dug up and sorted through the debris," Mr. Rathje said.

Mr. Rathje said he does worry that his findings will be interpreted to mean that such convenient environmental targets as disposable diapers and plastic do not matter. "Everything that goes into a landfill takes up space," he said. "What we hope to do is refocus attention on more significant issues without decreasing attention on the more symbolic articles." To avoid charges of bias, the Garbage Project gets its money from government, environmental groups and industry alike. A Fine-Tuned Method

The research material may be disgusting, but the analytical methods are refined. Mr. Rathje's team excavates layer by layer, their trowel a spinning bucket auger suspended from a derrick. Working back through time, they sort the contents into 150 coded categories. "The fastidiousness is amazing," said Mr. Murphy. "I visited the lab and they were looking at spoonfuls of grit with magnifying glasses, then weighing it carefully."

This touches on a matter of some sensitivity for Mr. Rathje, who bridles at descriptions of his activities. "They always say that I'm rooting, picking or poking," he fumed. "I don't root: I sort."