The book was titled, "Before the Sun Goes Down," written by Elizabeth Metzger Howard, and published in 1945, winning all kinds of literary prizes.

The text or the dust jacket said, "On an August day in 1880 Dr. Dan Field returned from a long vigil over a childbirth case, leaned against a pillar of his big brick house, and gazed into the drowsy afternoon-and into his acute awareness of the town about him.

"He knew every man, woman, and child in Willowspring."

Placing the book back on the shelf I wondered briefly where Willowspring might be.

Lawrence E. Spellman, curator of 200,000 maps at the Firestone Library, Princeton, N.J., had wondered enough to turn his search into a hobby and has collected close to 300 place names of areas he thinks-and in some instances knows-the authors had in mind when writing their novels.

Like most readers Spellman accepted (In "A Bell for Adano") Adano, the Italian town in Hershey's novel taken over by U.S. troops during WWII as the real place.

Research, however, proved differently and Spellman is still searching for Adano.

"There is an amalgam of impressions buried in the subconscious of the author when he writes," Spellman said.

"The physical characterization may be a blend of many places, or, on the other hand, it could differ."

When he discovers the area the author is writing about, he defends his findings as he would a fort.

He knows that East and West Egg in "The Great Gatsby," is the Great Neck area of Long Island. "A lot of people thought it was near Babylon or the Hamptons, but I knew the Fitzgeralds lived in Great Neck in '22 and '23, and the book was written in '24," he explained.

The 58-year-old Spellman's pursuit of truth may have had its beginning while still a youth at the family's home on Big Moose Lake, in upstate New York.

Many years earlier a local man murdered his pregnant girl friend, rowed out onto the lake and dropped the body over the side.

It was this incident that Theodore Dreiser based his novel "An American Tragedy," but changed the name of the lake to Big Bittern.

A retired colonel from the airborne infantry, his college years were spent at Hamilton, where he majored in English literature. When he retired from theArmy he enrolled at Rutgers where he received a masters in library science before joining the staff at Princeton 12 years ago.

The span of time Spellman is dealing with runs from 1900 to 1975. It has been suggested by some members of the Princeton English Department that a geographical dictionary on the subject could prove useful.

He has been approached by two publishers, but Spellman feels that he would need at least 1,000 place names before going into print.

"I am doing American novels exclusively and presently am researching Pulitzer Prize-winning writers of fiction," Spellman added, "and I intend to move on to the Nobel Laureates who wrote novels."

Shifting to the modern novel, Spellman said he had not read "Peyton Place," but had heard from people who had tried to locate the New England town in the Grace Metalious book, without success.

Grover's Corner, N.H., the locale of the play "Our Town," surfaced after some research.

"I knew that Thornton Wilder and worked in the area, so I studied a street map and found Grover Street in Peterbrough, N.H." Spellman said.

Several places remain buried in the authors' minds: (Ox Bow), the Nevada lynching site in Walter van Tilburg Clark's "The Ox-Bow Incident;" Frenchman's Bend, a small Mississippi town in Faulkner's "The Hamlet," and Elysium, a southwest Pacific port of call in Thomas Hoggen's "Mr. Robert's," have not been pinpointed.

Seeking aid in his search for names Spellman sent an author's query to The N.Y. Times Book Review asking for information on his interest.

His return mail was heavy and he has been corresponding with people offering their ideas of the locations.

"Of course," Spellman said, "if the author is alive and can be reached it makes things a lot easier."

Spellman tossed out a few places for teasers, saying "Hooverille, a California camp in Steinbeck's, "The Grapes of Wrath' of course was a generic term to designate a temporary camp for hobos or migrant workers during the depression.

"But Cannery Row is an actual location, and that will be in the book."

Altmont, in Thomas Wolfe's Look Homeward Angel," is Asheville, N.C.

Ilium, N.Y., in Kurt Vonnegut's, "Slaughterhouse Five," is Schenetady; and Midland City in "Breakfast of Champions" is based on Vonnegut's home town, Indianapolis.

The Gopher Prairie, appearing in Sinclair Lewis' "Main Street," is a combination of several Minnesota landscapes surrounding the town of Sauk Center.

But Lewis spread a smokescreen over his fictitious state, Winnemac, bringing alive Spellman's theory about the subconscious of the author and the physical characterizations being a blend of many places.

"Winnemac," bounded by Michigan, Ohio, Illinois and Indiana has Spellman admitting a temporary retreat when he says, "Some places just don't exist."

Spellman began his literary detective work as a hobby, and it remained that way for about two years-until the offers to publish turned his quiet quest into a task.

"It's one thing I enjoy though," he said. "It would take four or five years including a year's sabbatical, but the sabbatical is up in the air at my age, if I plan to retire at 65."

I thought again about Willowspring, but quickly relaxed, assured that Spellman would find it one day.

Until then the good Dr. Field could rest against the pillar of his big brick house gazing into a drowsy afternoon, content that he knew "every man, woman and child in Willowspring." CAPTION: Picture, Lawrence E. Spellman, by AP