Diagram
                                Date
                            
                            
                                1687
                            
                            
                        
                            
                            
                            
                                Creator
                            
                            
                                Unknown, Artist
                            
                            
                        
                            
                            
                            
                                Object type
                            
                            
                            
                        
                            
                            
                            
                                Archive reference number
                            
                            
                            
                        
                            
                            
                            
                                Manuscript page number
                            
                            
                                p4
                            
                            
                        
                            
                            
                            
                                Material
                            
                            
                            
                        
                            
                            
                            
                                Dimensions
                            
                            
                                height (page): 179mm
width (page): 152mm
                            
                        
                            
                            
                            width (page): 152mm
                                Subject
                            
                            
                            
                        
                            
                            
                            
                                Description
                            
                            
                                This sketched diagram appears on back of letter from Henry Justel to Edmond Halley sending a tract by Philippe de la Hire. De la Hire's paper concerned a circular magnetic needle he had created, which always respected the true meridian. The paper was read to the Royal Society on 22 June 1687, and printed in the Philosophical Transactions of the Royal Society, vol. 16, no. 188 (1687), p. 344.
                            
                            
                        
                            
                            
                            
                                Object history
                            
                            
                                At the meeting of the Royal Society on 22 June 1687, 'A printed paper of Mons. de la Hire was read, concerning a magnetical needle contrived by him in a circular form, supposing that such a circle would always respect the true meridian with the same points thereof, and the magnetical virtue change its place therein, alledging some experiments of the alteration of the poles of a magnet analogous to what is found in the globe of the earth' (Birch 4:543).
                            
                            
                        
                            
                            
                            
                                Related fellows
                            
                            
                                Edmond Halley (1656 - 1742, British) , Astronomer
Henri Justel (1620 - 1693, French) , Royal Librarian, Librarian
                            
                        
                            
                            
                            Henri Justel (1620 - 1693, French) , Royal Librarian, Librarian
                                Associated place