It took Franklin Toker 12 years to complete his book “Fallingwater Rising: Frank Lloyd Wright,… It took Franklin Toker 12 years to complete his book “Fallingwater Rising: Frank Lloyd Wright, E. J. Kaufmann, and the Greatest House on Earth.” But for Toker, an art history professor at Pitt, this wasn’t just another book about houses.

“I’ve been very insistent,” Toker told an audience which extended out of the Frick Fine Arts classroom and into the hallway yesterday afternoon.

From the beginning, he intended “Fallingwater Rising” to be specifically not an art or architecture book. Instead, Toker aimed to get into the mind of Kaufmann, one of the two forces behind Fallingwater, and go from there.

Toker gave his first lecture on Fallingwater at Pitt 12 years ago. Since then, he’s read more than 30,000 of Wright’s personal letters, examined the joists and rebars underlying Fallingwater’s living room floor, and hounded the current Time-Life archivist in an attempt to establish a connection between Kaufmann and the magazine’s staff.

“He told me to go to hell,” Toker said.

Still, Toker said, “I’ve had a lot of lucky breaks.”

He was able to add a chapter on the construction of Fallingwater, something he didn’t think he could understand with no knowledge of engineering, because of what he called “the crisis of the 1990s,” in which the cantilevers that held up Fallingwater’s structure began to deflect. The entire living room was dismantled to correct mistakes caused by weakened beams and joists, and Toker got an up-close look at the physical structure of the building.

Although Toker’s book includes chapters on the design, construction and site of Fallingwater, his focus was on the men behind Fallingwater and what he called their “psychohistory.”

“I tried to project myself into the ether between these two fascinating human beings,” he said.

That ether was often tense; Kaufmann’s own family was shocked when Kaufmann “threw Wright over” in favor of a new partner for his third big project, a Bauhaus-style building in California.

“He was, after all, a merchant, and merchants require new materials and new ways of appealing to their audience,” Toker said.

On a personal level, the men’s partnership was unlikely. Wright, often hailed as an “all-American” architect, was a supporter of Charles Lindbergh; one of Toker’s slides depicted the men shaking hands, a swastika displayed prominently on Lindbergh’s arm. Meanwhile, Kaufmann, a Jew, remained an outsider in Pittsburgh despite his professional success.

The men behind Fallingwater weren’t the only ones to capture Taker’s interest.

“I wonder about Lillian,” Toker said of Kaufmann’s wife, displaying a reproduction of a portrait of a nearly nude woman that many believe to be Lillian.

Toker relied on more than just letters for history. He noted that while Lillian slept in the master’s suite of Fallingwater, Kaufmann spent at least part of his time elsewhere.

Characterized in part by his libido, “which was hyperactive,” Toker noted that Kaufmann fathered at least one illegitimate child.

“Fallingwater Rising” is scheduled to be released by Knopf, a division of Random House publishers, in fall of 2003.

Toker is already planning his next book, an examination of Diego Velasquez’s painting “Las Meninas,” but said that he anticipates a long wait for its release.

“I’m going to use every weapon I used on ‘Fallingwater,'” he said.