After murdering Hughes's lover—fiction—Muybridge is forced to move to Philadelphia. By then, his cameras are able to record animals as they trot, canter, gallop—and similarly, his human subjects as they stroll, wrestle, dance, and even disrobe. So toward the end of Moments Captured, and this is truth, Muybridge invents one of the first, if not the first, motion-picture projector.

"Whenever I invented incidents," Seidman says, "I tried to make those events historically credible, tried to be true to what was intellectually and technically possible in the 1870s and 1880s. I took this license with history for one simple reason: In order to make the novel's narrative as compelling as possible."

The "real" Eadweard Muybridge was wildly eccentric and a much stranger character, Seidman told me, compared to the protagonist of Moments Captured. "I was less interested in the man's pathology than in his soaring ambition and dedication to his work." Seidman's Muybridge is, therefore, consumed and partly destroyed by the obsessive, love-driven desire to produce superb photographs.

Seidman was also fascinated by the challenges confronting itinerant 19th-century photographers, and in "a pioneering perfectionist who doesn't 'win.'" In crafting his narrative he drew upon the machinery of America's expansionist history to inhibit, "even grind away at the three principal characters. Their single-track ambitions blind them to other realities—Muybridge's photographs, Holly's dedication to feminism, and Muybridge patron Leland Stanford's epic construction of the transcontinental railroad, each of these undertakings collides with immovable forces."

To make the book a "technological romance," Seidman invented Holly Hughes: "I made her a dancer so that the novel could be about a strong, beautiful woman who Muybridge felt compelled to photograph in motion." In fact, Muybridge was married to Flora Shallcross Stone, a divorcee roughly half his age whom a contemporary described as a boring, superficial woman.

Seidman also wanted his characters to work out their conflicts on what he calls an epic canvas. So while reality, Muybridge did not photograph the Central Pacific Railroad's deadly race to lay track over the Sierra Nevada, Seidman placed him in the mountains because the story was so engaging. And to allow for the murder on which the plot turns—and which recalls The Devil in the White City—Seidman had to make poor Muybridge "descend into a psychological hell."

And what of its main character's signature achievement? Seidman may have fudged how Muybridge got there, but he knows the impact of his invention is very real. "Those of us who watched the 30th Summer Olympics were awed by the stop-motion shots of athletes—Muybridge's 19th-century technological innovations were visible everywhere in the NBC telecasts," he says. "Yet only a handful of the tens of millions of viewers had ever heard the name of the photographer who invented stop action." If, then, more people come to know Muybridge in part because of a spicy, fictional plot, there's nothing fake about Moments Captured's impact.

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