published notes for his auditors, and designed his own apparatus, including a renowned planetarium to demonstrate the solar system, and a machine to explain tidal motion. In 1717 Desaguliers lodged at Hampton Court and lectured in French to King George I and his family. Demonstrator at the Royal Society In 1714 Isaac Newton, President of the Royal Society, invited Desaguliers to replace Francis Hauksbee (1660 – 1713) as demonstrator at the Society's weekly meetings; he was soon thereafter made a Fellow of the Royal Society. Desaguliers promoted Newton's ideas and maintained the scientific nature of the meetings when Hans Sloane took over the Presidency after Newton died in 1727. Desaguliers contributed over 60 articles to the Philosophical Transactions of the Royal Society. He received the Society's prestigious Copley Medal in 1734, 1736 and 1741. The last award was for his summary of knowledge to date on the phenomenon of electricity. He had worked on this with Stephen Gray, who at one time lodged at the Desaguliers' home. Desaguliers's "Dissertation concerning Electricity" (1742), in which he coined the terms conductor and insulator, was awarded a gold medal by the Bordeaux Academy of Sciences. Patronage of the Duke of Chandos James Brydges, 1st Duke of Chandos appointed Desaguliers as his chaplain in 1716, but probably as much for his scientific expertise as his ecclesiastic duties. He was also gifted the living of St Lawrence Church, Little Stanmore, which was close to the Duke's mansion called Cannons, then under construction at nearby Edgware. The church was rebuilt in the baroque style in 1715. As the chapel at Cannons was not completed until 1720, the church was the location of first performances of the so-called Chandos Anthems by George Frideric Handel who was, in 1717/18, like Desaguliers, a member of the Duke's household. The Cannons estate benefited from Desaguliers' scientific expertise which was applied to the elaborate water garden there. He was also technical adviser to an enterprise in which Chandos had invested, the York Buildings Company, which used steam-power to extract water from the Thames. In 1718 Desaguliers dedicated to the Duke his translation of Edme Mariotte's treatise on the motion of water. It is perhaps no coincidence that in the summer of 1718 Handel composed his opera Acis and Galatea for performance at Cannons. In this work the hero Acis is turned into a fountain, and since, by tradition, the work was