Diagrams of cycloids
                                Date
                            
                            
                                15 July 1673
                            
                            
                        
                            
                            
                            
                                Creator
                            
                            
                                John Wallis (1616 - 1703, British) , Mathematician
                            
                            
                        
                            
                            
                            
                                Object type
                            
                            
                            
                        
                            
                            
                            
                                Archive reference number
                            
                            
                            
                        
                            
                            
                            
                                Manuscript page number
                            
                            
                                p1
                            
                            
                        
                            
                            
                            
                                Material
                            
                            
                            
                        
                            
                            
                            
                                Dimensions
                            
                            
                                height (page): 312mm
width (page): 202mm
                            
                        
                            
                            
                            width (page): 202mm
                                Subject
                            
                            
                            
                        
                            
                            
                            
                                Description
                            
                            
                                Diagrams of 'imperfect' cycloids by John Wallis. In response to Francis Jessop's comments on his theory of tides, Wallis explained that the imperfect cycloid did not have its base ba as the perpendicular to the curve ac (as Jessop supposed and as shown in the top diagram), but that the base ba was a tangent to the curve ac and perpendicular to it at ap (as in the bottom figure). Wallis originally made his comments in the margin of Jessop's letter dated 25 June 1673 and addressed to Martin Lister, who had forwarded it to Henry Oldenburg so that Wallis could comment on it. 
Copies can be found at LBO/6/190 and LBC/6/219. For Jessop's diagrams, see EL/I1/165/001.
Francis Jessop (1638-91) was a freeman of the Cutler's Company of Sheffield, and a close friend of John Ray (Correspondence of Henry Oldenburg, ed. by Hall and Hall, vol. 10, p. 71n).
                            
                            
                        
                            
                            
                            Copies can be found at LBO/6/190 and LBC/6/219. For Jessop's diagrams, see EL/I1/165/001.
Francis Jessop (1638-91) was a freeman of the Cutler's Company of Sheffield, and a close friend of John Ray (Correspondence of Henry Oldenburg, ed. by Hall and Hall, vol. 10, p. 71n).
                                Related fellows
                            
                            
                                John Wallis (1616 - 1703, British) , Mathematician
Henry Oldenburg (1612 - 1677, German) , Scientific correspondent
                            
                        
                            
                            
                            Henry Oldenburg (1612 - 1677, German) , Scientific correspondent
                                Associated place