3 April 1706. Jean Christophe published in the Philosophical Transactions a description of the solar eclipse that he had observed in Geneva on 12 May of that year. He died at Geneva on 18 October 1720. Jean Christophe was married in 1709 to Catherine, daughter of Jean Gassand of Forcalquier, in Provence. Catherine's will was proved at London in March 1752. Nicolas himself was never married. Education and patronage Nicolas Fatio received his elementary schooling at the Collège de Genève, proceeding in 1678 to the Académie de Genève (now the University of Geneva), where he remained until 1680. At the Academy he came under the influence of the rector, Jean-Robert Chouet, a prominent Cartesian. Before he was eighteen, Fatio wrote to the director of the Paris Observatory, the astronomer Giovanni Domenico Cassini, suggesting a new method of determining the distances to the Sun and Moon from the Earth, as well as an explanation of the form of the rings of Saturn. With Chouet's support, Fatio travelled to Paris in the spring of 1682 and was warmly received by Cassini. That same year, Cassini presented his findings on the astronomical phenomenon of zodiacal light. Fatio repeated Cassini's observations in Geneva in 1684, and in 1685 he offered an important development of Cassini's theory, which was communicated by Chouet in the March 1685 number of Nouvelles de la république des lettres. Fatio's own Lettre à M. Cassini touchant une lumière extraordinaire qui paroît dans le Ciel depuis quelques années ("Letter to Mr. Cassini concerning the extraordinary light that has appeared in the Heavens for some years") was published in Amsterdam in 1686. There Fatio correctly explained the zodiacal light as sunlight scattered by an interplanetary dust cloud (the "zodiacal cloud") that straddles the ecliptic plane. Fatio then studied the dilatation and contraction of the eye's pupil. He described the fibres of the anterior uvea and the choroid in a letter to Edme Mariotte, dated 13 April 1684. That same year he published an article in the Journal des sçavans on how to improve the fabrication of lenses for the objectives of telescopes. Also in 1684, Fatio met the Piedmontese Count Fenil, who, having offended the Duke of Savoy and the King of France, had taken refuge in the house of Fatio's maternal grandfather in Alsace and then at Duillier. Fenil confided to Fatio his plan to stage a raid on the beach