throne jointly to James's Protestant daughter Mary and to her husband, the Dutch Prince William of Orange. Fatio also had an opportunity to enhance his intellectual reputation during Huygen's visit to London in the summer of 1689. Fatio met Newton, probably for the first time, at a meeting of the Royal Society on 12 June 1689. Newton and Fatio soon became friends and Newton even suggested that the two share rooms in London while Newton attended the post-Revolutionary session of Parliament, to which he had been elected as member for the University of Cambridge. In 1690, Fatio wrote to Huygens outlining his own understanding of the physical cause of gravity, which would later become known as "Le Sage's theory of gravitation". Soon after that, he read his letter to Huygens before the Royal Society. Fatio's theory, on which he continued to work until his death, is based on minute particles streaming through space and pushing upon gross bodies, an idea that Fatio probably derived in part from his successful explanation of zodiacal light as sunlight scattered by a cloud of fine dust surrounding the Sun. Fatio turned down Newton's offer to reside in Cambridge as his assistant, seeking instead academic preferment in the Netherlands. In the spring of 1690 he traveled to The Hague as tutor to two of John Hampden's nephews. There, Fatio shared with Huygens a list that he had compiled of errata to Newton's Principia. Fatio and Huygens collaborated on problems relating to differential equations, gravity, and optics. At this time, Huygens shared with Gottfried Leibniz some of Fatio's work on differential equations. Fatio returned to London in September 1691, following the death of one of his pupils. He vied unsuccessfully for the Savilian Professorship of Astronomy at Oxford, a post that had been left vacant by the death of his friend Edward Bernard. Fatio convinced Newton to write a new treatise on a general method of integration, De quadratura curvarum. Initially, he also expected to collaborate with Newton on a new edition of the Principia that would include Fatio's mechanical explanation of gravity. By the end of 1691, Fatio realised that Newton would not proceed with that project, but he still hoped to collaborate with Newton on corrections to the text of the Principia. In a letter to Huygens, Fatio wrote, concerning those corrections, "I may possibly undertake it myself, as I know no one who