admiring essays on British government, literature, religion, and science in Letters Concerning the English Nation (London, 1733). In 1734, they were published in Rouen as Lettres philosophiques, causing a huge scandal. Published without approval of the royal censor, the essays lauded British constitutional monarchy as more developed and more respectful of human rights than its French counterpart, particularly regarding religious tolerance. The book was publicly burnt and banned, and Voltaire was again forced to flee Paris. Château de Cirey In 1733, Voltaire met Émilie du Châtelet (Marquise du Châtelet), a mathematician and married mother of three, who was 12 years his junior and with whom he was to have an affair for 16 years. To avoid arrest after the publication of Lettres, Voltaire took refuge at her husband's château at Cirey on the borders of Champagne and Lorraine. Voltaire paid for the building's renovation, and Émilie's husband sometimes stayed at the château with his wife and her lover. The intellectual paramours collected around 21,000 books, an enormous number for the time. Together, they studied these books and performed scientific experiments at Cirey, including an attempt to determine the nature of fire. Having learned from his previous brushes with the authorities, Voltaire began his habit of avoiding open confrontation with the authorities and denying any awkward responsibility. He continued to write plays, such as Mérope (or La Mérope française) and began his long researches into science and history. Again, a main source of inspiration for Voltaire were the years of his British exile, during which he had been strongly influenced by the works of Isaac Newton. Voltaire strongly believed in Newton's theories; he performed experiments in optics at Cirey, and was one of the promulgators of the famous story of Newton's inspiration from the falling apple, which he had learned from Newton's niece in London and first mentioned in his Letters. In the fall of 1735, Voltaire was visited by Francesco Algarotti, who was preparing a book about Newton in Italian. Partly inspired by the visit, the Marquise translated Newton's Latin Principia into French, which remained the definitive French version into the 21st century. Both she and Voltaire were also curious about the philosophy of Gottfried Leibniz, a contemporary and rival of Newton. While Voltaire remained a firm Newtonian, the Marquise adopted certain aspects of Leibniz's critiques. Voltaire's own book Elements of the Philosophy of Newton made the great scientist accessible