the royal household and Brian Duppa, the Dean of Christ Church, Oxford, was his tutor. Neither man thought that the study of science subjects was appropriate for a future king, and Newcastle even advised against studying any subject too seriously. However, as Charles grew older, the renowned surgeon William Harvey was appointed his tutor. He was famous for his work on blood circulation in the human body and already held the position of physician to Charles I; his studies were to influence Charles's own attitude to science. As the king's chief physician, Harvey accompanied Charles I to the Battle of Edgehill and, although some details are uncertain, he had charge of Prince Charles and the Duke of York in the morning but the two boys were back with the king for the start of battle. Later in the afternoon, with their father concerned for their safety, the two princes left the battlefield accompanied by Sir W. Howard and his pensioners. During his exile, in France, Charles continued his education, including physics, chemistry and mathematics. His tutors included the cleric John Earle, well known for his satirical book Microcosmographie, with whom he studied Latin and Greek, and Thomas Hobbes, the philosopher and author of Leviathan, with whom he studied mathematics. In France, Charles assisted his childhood friend, the Earl of Buckingham, with his experiments in chemistry and alchemy, with the Earl convinced he was close to producing the philosopher's stone. Although some of Charles's studies, while abroad, may have helped to pass the time, on his return to England he was already knowledgeable in the mathematics of navigation and was a competent chemist. Such was his knowledge of Naval Architecture that he was able to participate in technical discussions on the subject with Samuel Pepys, William Petty and John Evelyn. The new concepts and discoveries being found at this time fascinated Charles, not only in science and medicine, but in topics such as botany and gardening. A French traveller, Sorbier, while visiting the English court, was astonished by the extent of the king's knowledge. As king, Charles now freely indulged in his many interests, including astronomy, which had been stimulated by a visit to Gresham College, in October 1660, to see the telescopes made by the astronomer Sir Paul Neile. Charles was so impressed by what he saw that he ordered his own 36' telescope which he had installed in the