Like her illustrious friend, the great Humboldt, Mary Somerville was possessed of extraordinary physical vigor, and, like him, she retained her mental powers unimpaired until the last. And like her great rival in mathematics, Maria Gaetana Agnesi, she was always "beautifully womanly." Her scientific and literary occupations did not cause her to neglect the duties of her household or to disregard "the graceful and artistic accomplishments of an elegant woman of the world." Her daughter Martha writes of her: "It would be almost incredible were I to describe how much my mother contrived to do in the course of the day. When my sister and I were small children, although busily engaged in writing for the press, she used to teach us for three hours in the morning, besides managing her house carefully, reading the newspapers--for she was always a keen and, I must add, a liberal politician--and the most important new books on all subjects, grave and gay. In addition to this, she freely visited and received her friends.... Gay and cheerful company was a pleasant relaxation after a hard day's work."[129] The life of Mary Somerville, like that of Gaetana Agnesi, proves that the pursuit of science is not, as so often asserted, incompatible with domestic and social duties. It also disposes of the fallacy, so generally entertained, that intellectual labor is detrimental to the health of women and antagonistic to longevity. The truth is that it is yet to be demonstrated that intellectual work, even of the severest kind, is, _per se_, more deleterious to women than to those of the stronger sex. Scarcely less remarkable as a mathematician was Mrs. Somerville's distinguished contemporary, Janet Taylor, who was known as the "Mrs. Somerville of the Marine World." She was the author of numerous works on navigation and nautical astronomy which in their day were highly prized by seafaring men. In recognition of her valuable services to the marine world she was placed on the civil list of the British government. As an eminent mathematician as well as a "representative of the highest intellectual accomplishments to which women have attained," Sonya Kovalevsky will ever occupy an honored place among the votaries of science. In many respects this richly endowed daughter of Holy Russia was _par excellence_ the woman of genius of the latter half of the nineteenth century. She was born in Moscow in 1850, but although her career was brief it was one of meteoric splendor. At an early age she exhibited an unusual talent for mathematics and an unquenchable thirst for knowledge. Not being able to obtain in her own country the educational advantages she desired, she resolved at the age of eighteen to go to Germany with a view of pursuing her studies there under more favorable auspices.