Mary Fairfax Somerville´s writings on mathematics and science made her a household name in Victorian England. Her most well-known work was Mechanism of the Heavens (1831), a highly valued exposition of Laplace. While most of her titles were popular expositions, her book on Physical Geography was used as a standard textbook until the 20th century. Her publisher treated her with great deference and her influential writings led her to receive an annual pension from the British government from 1835 until her death in 1872. Yet Mary Somerville could not get her favorite project, a mathematical textbook on the calculus of variations, published. Why??? In answering this question, I will explore the concept of originality in mathematics (and in publishing), and how class and gender might have played a role. The talk will summarize my research on the manuscript and the correspondence between her and her publisher, and how I was led to this topic as part of researching a project currently under contract with Johns Hopkins University Press: The Material of Intellect: A Historical Sourcebook on Women and Mathematics, 1500-1900.