In one of her best known poems, George Eliot wrote of “the choir invisible,” the “immortal dead who live again / In minds made better by their presence.” In the work of which this book is the culmination, I have been sustained and inspired by my own Choir Invisible, who have enlarged my view of what was possible and accompanied me on what has turned out to be one of the most challenging and rewarding journeys of my life. I dedicate this book to them.

The group has many members, all of whose voices have been important, but there are four who have been particularly strong presences in this work: my grandmothers, Nina Bookhardt Neeley and Jessie Rivers Von Harten, my great aunt Myrtle Von Harten Davison, and my dear friend Ann Doner Vaughan. Their capacity to inspire and support others has not been diminished by the passage from this life to the next.

The Choir also includes Mary Somerville, whom I have never properly met but who has been an excellent companion and most agreeable subject through the years I have spent with her. I have on occasion been accused of acting too much as her advocate. On one level, of course, this charge is quite justified. For as long as I have truly appreciated what she accomplished, I have felt an obligation to help bring it to light. An unusual and fortuitous set of circumstances put me in a position to comprehend her work, and I have worked hard to help others do so. I would add that I did not begin this project as Somerville's advocate.

I began this project with the nave assumption that Mary Somerville was a forgotten woman. My reasons for thinking she was forgotten were straightforward: I had read dozens of comprehensive histories of science, and I had never seen her treated as anything more than a footnote, and rarely even as a footnote. As I examined in detail how she had been treated by the history of science, I realized that something much more interesting than forgetting was going on. She was not forgotten. She just could not be integrated into the patterns of traditional history of science. The eminence she had achieved in her own time was overshadowed by the fact that there was no major discovery to which her name could be attached and by the conceptual filters that either discounted women's achievements or failed altogether to recognize them.

The “Forgetting” of Mary Somerville

Of all the aspects of Mary Somerville's life and career, her fall into relative obscurity – what I will call here her “forgetting” – is one of the most interesting. By “forgetting” I mean not the literal loss of knowledge of her existence but rather her absence from standard histories of science. During her lifetime, she had been an integral part of the living scientific community, but she was an outsider to history.

What Mary Somerville was and what she accomplished are captured in the self-portrait that serves as the frontispiece for this book. One of the most striking characteristics of the self-portrait is the directness with which the subject meets the gaze of the viewer. She deliberately presented herself as an author, pen in hand and seemingly in the midst of composition. Her clothing seems decidedly, perhaps even selfconsciously, feminine. The face is portrayed with much more accuracy and detail than any other part of the portrait except for her hands. In fact, much of the background is treated in an impressionistic way that almost suggests that the portrait is not yet finished. For the style of portraiture of the time, the gaze is uncommonly direct. It is neither reluctant nor aggressive, but, rather, discerning, perspicacious, shrewd.

In one respect, the directness of the gaze reflects her voice as an author, the hard-won confidence and authority that Somerville enjoyed as a scientist and an intellectual. Her life story demonstrates what a great distance had to be traversed in order for her – or for any woman of her time – to overcome the norms of deference that she surmounted in meeting the viewer's gaze so directly.

The more one learns about Mary Somerville's childhood and early life, the more surprising her accomplishments appear. Her father had been sent to sea at the age of ten and had little formal education. Her mother read only the Bible, the newspaper, and sermons. Her parents' educational goals for their daughter were for her “to write well and keep accounts, which was all that a woman was expected to know” (PR 25) and to learn what might be called the domestic fine arts: needlework, pastry and jam making, gardening, and piano. As a child, she had great difficulty remembering names and dates and found the catechism incomprehensible. Though she could read Pilgrim's Progress at the age of eight or nine, she did not master the basics of writing and arithmetic until she was thirteen years old. She never became adept at spelling or doing simple sums.

Her family and friends generally disapproved of her penchant for reading, and she was prevented from studying Euclid at night because she was depleting the family candle supply and her family feared she would follow in the footsteps of an acquaintance who had gone “raving mad about the longitude!” (PR 54) In girlhood, her education was inhibited by old-school prejudices, lack of money, and the demands of acquiring and practicing the domestic and artistic skills required of a woman of the middle class; in early adulthood, she was limited by isolation and an unsupportive spouse.

As previous chapters have demonstrated, one of the hallmarks of Somerville's rhetoric of science was a theme she borrowed from the eighteenth-century scientific poets – the idea that science was a pathway to God, a form of elevated meditation, and that detailed examination of nature revealed the intricacy, drama, harmony, and beauty that God had incorporated into the design of universe. In this view, the capacity for exact calculation and for in-depth and precise understanding of phenomena was an aid rather than a hindrance to appreciating the wonders of the creation. She pursued the creative possibilities of this idea in new settings in Physical Geography and On Molecular and Microscopic Science. In Mechanism and Connexion, Somerville had provided her readers with an expanded conception of the universe and surveyed the celestial and some aspects of the terrestrial spheres. In Physical Geography and On Molecular and Microscopic Science, she turned her attention to the remainder of God's handiwork – the earth, the sea, the air, and their many animal and vegetable inhabitants. As she explored and presented detailed scientific accounts of these subjects, Somerville took up another theme borrowed from the scientific poets: the analogy between the worlds revealed by the telescope and microscope.

Mary Somerville was an eminent scientist. She achieved an international reputation that established her as both the leading woman of science in Great Britain during the nineteenth century and as one of that century's most celebrated intellectual women. (Patterson 1983) Somerville's greatest scholarly strength was in mathematics, which she mastered at a very high level, but her expertise extended throughout the established and emerging physical and life sciences. She was the first woman to publish experimental results in the Philosophical Transactions of the Royal Society as well as the first – and only – woman to have her bust placed in the great hall of the Royal Society. Hers was the first name on John Stuart Mill's petition to obtain the vote for women in Great Britain. (PR 345) When the founders of Oxford University's first nondenominational women's college sought a name to exemplify ideals of high intellectual achievement for women, “Somerville” seemed an obvious choice. (Adams 1996)

In a letter written in 1829, David Brewster pronounced her “certainly the most extraordinary woman in Europe – a Mathematician of the very first rank.”

The last page of the second draft of Mary Somerville's autobiography, written near the end of her long life, contains only a few lines. These lines are recorded in an elderly hand that deteriorates rapidly as it moves down the page and seems to contradict the words themselves.

The page is very wrinkled and appears to have been crumpled and then smoothed out again. The words printed here in italics are omitted from the published version. The circumstances that led to the crumpling of the page and the omission of the final words remain, like many other things about Mary Somerville, somewhat of a mystery.

Personal Recollections holds particular interest because it sheds light on her published works and also offers answers to questions left largely unanswered by other sources. What kind of a person was Mary Somerville? What kind of life did she lead? What were her regrets and fears? How did she view her own career and abilities? What were her views on women in science and society?

The “full meal” to which Edgeworth refers is the “Preliminary Dissertation” on the Mechanism of the Heavens. The terms she uses and the responses she describes seem more appropriate for an epic poem than a scientific treatise. The “Preliminary Dissertation” combined the qualities of both. Although it was written for and originally published as part of Mechanism, the “Preliminary Dissertation” was considered sufficiently valuable to be published independently in 1832. It epitomizes Somerville's most important abilities and contributions as a writer and a philosopher and provided the basic structure for one of Somerville's most popular books, On the Connexion of the Physical Sciences, which sold over 15,000 copies. As mentioned earlier, Mechanism established Somerville's reputation in elite science. Because Mechanism and Connexion were Mary Somerville's most esoteric and technical writings, they provide the most convincing demonstration of her ability to portray science as both exact calculation and elevated meditation. They also illustrate the intellectual quality that Whewell defined in gendered terms as the peculiar illumination of the female mind, a quality that ultimately reveals itself more through its blurring of gendered traits than its exemplification of female ones.

Three large windows with extensive views dominate the room in which I wrote most of this book. As I immersed myself in the scientific writings of Mary Somerville and looked at the world outside through the lenses her writing provided, those very familiar views took on an entirely new aspect, and the world of nature became much more vast, vivid, and dynamic than I had ever imagined it could be. My own powers of perception had been expanded as I watched Somerville exercise hers. I hope I have succeeded in conveying the power of Somerville's transforming vision. Its power derives in large part from Somerville's ability to use science to heighten perception and stimulate imagination.

The utilitarian goals commonly associated with science often overshadow its other functions.