Harriet Martineau’s return from London in winter 1855, after her diagnosis with heart disease, marked the end of a decade of remarkable physical vigour: from this time, she never left her Ambleside home again. Convinced she would die at any moment, she resigned herself to the invalid life – for the next twenty-one years; but quite in character, Martineau’s spirited ‘need of utterance’ manifested itself in the form of books (about a dozen volumes) and a staggering array of periodical articles (well over 1,000). Indeed, her first act as an invalid was to write her over 900-page autobiography – within a few months. It may well be claimed that Martineau’s intellectual productivity increased, if anything, in proportion to her enforced physical inactivity – her abundant correspondence alone attesting to this point. The constant stream of visitors, particularly from America, honoured her with their pilgrimages to The Knoll and reinforced her status as a sage ‘From the Mountain’, her hermit persona providing a curious juxtaposition with her indefatigable intellectual vigour. She once quipped that London ‘is so kind as to come to me’, rather than her to it; now, her visitors hailed from all over the world.