However remarkable this is, I’m more interested in the kind of focus that Somerville seemed to possess. How can one in an environment such as hers, with constant distractions, little social support, and continuous obligations, manage to focus long enough not only to learn an impressive breadth of subjects, but to such depths that the French mathematician Siméon Poisson once remarked that “there were not twenty men in France who could read [her] book”?