Diagram regarding the properties of a cycloid
                                Date
                            
                            
                                10 February 1662
                            
                            
                        
                            
                            
                            
                                Creator
                            
                            
                                Christiaan Huygens (1629 - 2006, Dutch) , Natural philosopher
                            
                            
                        
                            
                            
                            
                                Object type
                            
                            
                            
                        
                            
                            
                            
                                Archive reference number
                            
                            
                            
                        
                            
                            
                            
                                Manuscript page number
                            
                            
                                p1
                            
                            
                        
                            
                            
                            
                                Material
                            
                            
                            
                        
                            
                            
                            
                                Dimensions
                            
                            
                                height (page): 199mm
width (page): 153mm
                            
                        
                            
                            
                            width (page): 153mm
                                Subject
                            
                            
                            
                        
                            
                            
                            
                                Description
                            
                            
                                The meeting of the Royal Society on 22 January 1662 discussed William Brouncker’s paper (Cl.P/1/15) proving that the curve of isochronous descent is a cycloid, which had been proven earlier by Christaan Huygens by other means. A copy of the paper was forwarded to Huygens by Robert Moray in a letter dated 3 February 1662. In his reply to Moray, in this letter dated 10 February, Huygens pointed out problems in part of Brouncker's diagram.
                            
                            
                        
                            
                            
                            
                                Object history
                            
                            
                                At the meeting of the Royal Society on 22 January 1662, ‘The pendulum experiment was discoursed of by the lord viscount Brouncker, who brought in the account and schemes of it; and a committee was appointed for making trials of it, consisting of his lordship himself, Mr. Boyle, Sir William Petty, Dr. Wilkins, and Dr. Wren. His lordship’s paper was ordered to be registered, and a copy of it made against the Friday following, and brought to Sir Robert Moray, to be sent to Mons. Huygens’ (Birch 1:70). 
At the meeting of the Royal Society on 12 March 1662, ‘It was ordered, that the amanuensis make three copies of the equation of days, sent by Monsieur Huygens to Sir Robert Moray, and translate them as soon as possible’ (Birch 1:78).
                            
                        
                            
                            
                            At the meeting of the Royal Society on 12 March 1662, ‘It was ordered, that the amanuensis make three copies of the equation of days, sent by Monsieur Huygens to Sir Robert Moray, and translate them as soon as possible’ (Birch 1:78).
                                Related fellows
                            
                            
                                Christiaan Huygens (1629 - 2006, Dutch) , Natural philosopher
Robert Moray (1608 - 1673, British) , Natural philosopher
William Brouncker, 2nd Viscount Brouncker of Lyons (1620 - 1684, British) , Mathematician
                            
                        
                            
                            
                            Robert Moray (1608 - 1673, British) , Natural philosopher
William Brouncker, 2nd Viscount Brouncker of Lyons (1620 - 1684, British) , Mathematician
                                Associated place