New England blossomed in the nineteenth century, producing a crop of distinctively American writers along with distinguished philosophers and jurists, abolitionists and scholars. A few of the female stars of this era-Emily Dickinson, Margaret Fuller, and Susan B. Anthony, for instance-are still appreciated, but there are a number of intellectual women whose crucial roles in the philosophical, social, and scientific debates that roiled the era have not been fully examined.

Among them is the astronomer Maria Mitchell. She was raised in isolated but cosmopolitan Nantucket, a place brimming with enthusiasm for intellectual culture and hosting the luminaries of the day, from Ralph Waldo Emerson to Sojourner Truth. Like many island girls, she was encouraged to study the stars. Given the relative dearth of women scientists today, most of us assume that science has always been a masculine domain. But as Renée Bergland reminds us, science and humanities were not seen as separate spheres in the nineteenth century; indeed, before the Civil War, women flourished in science and mathematics, disciplines that were considered less politically threatening and less profitable than the humanities. Mitchell apprenticed with her father, an amateur astronomer; taught herself the higher math of the day; and for years regularly "swept" the clear Nantucket night sky with the telescope in her rooftop observatory.

In 1847, thanks to these diligent sweeps, Mitchell discovered a comet and was catapulted to international fame. Within a few years she was one of America's first professional astronomers; as "computer of Venus"-a sort of human calculator-for the U.S. Navy's Nautical Almanac, she calculated the planet's changing position. After an intellectual tour of Europe that included a winter in Rome with Sophia and Nathaniel Hawthorne, Mitchell was invited to join the founding faculty at Vassar College, where she spent her later years mentoring the next generation of women astronomers. Tragically, opportunities for her students dried up over the next few decades as the increasingly male scientific establishment began to close ranks.

Mitchell protested this cultural shift in vain. "The woman who has peculiar gifts has a definite line marked out for her," she wrote, "and the call from God to do his work in the field of scientific investigation may be as imperative as that which calls the missionary into the moral field or the mother into the family . . . The question whether women have the capacity for original investigation in science is simply idle until equal opportunity is given them." In this compulsively readable biography, Renée Bergland chronicles the ideological, academic, and economic changes that led to the original sexing of science-now so familiar that most of us have never known it any other way.