A pocket-sized level
                                Date
                            
                            
                                27 March 1686
                            
                            
                        
                            
                            
                            
                                Object type
                            
                            
                            
                        
                            
                            
                            
                                Archive reference number
                            
                            
                            
                        
                            
                            
                            
                                Manuscript page number
                            
                            
                                p336
                            
                            
                        
                            
                            
                            
                                Material
                            
                            
                            
                        
                            
                            
                            
                                Dimensions
                            
                            
                                height (page): 320mm
width (page): 195mm
                            
                        
                            
                            
                            width (page): 195mm
                                Subject
                            
                            
                            
                        
                            
                            
                            
                                Content object
                            
                            
                            
                        
                            
                            
                            
                                Description
                            
                            
                                A figure of a pocket-sized level designed by Robert Hooke, in a letter by Thomas Gale to St George Ashe dated 27 March 1686.  Although this figure differs considerably from the one found among the papers of the Dublin Philosophical Society (Add. Ms. 4811, 117v, British Library), the principles illustrated here are the same. 
This figure is copied from EL/H3/42/001.
                            
                            
                        
                            
                            
                            This figure is copied from EL/H3/42/001.
                                Transcription
                            
                            
                                '...a new Level, whereby he pretends by a very small Instrument, and which may be made almost to be carried in your Pocket to discover the Horizontal Line for all Uses to the utmost Rigour of Exactness.
AB, CD are two Rulers at right Angles, the one to the other. EF is a third erected at right Angles on the Intersection of the other two, but cut away at the bottom, that so the Wire FG may be fasten'd to the Center of the Instrument in F, to give the Axis EF a small Inclination towards C.
Transcribed by the Making Visible project
                            
                        
                            
                            
                            AB, CD are two Rulers at right Angles, the one to the other. EF is a third erected at right Angles on the Intersection of the other two, but cut away at the bottom, that so the Wire FG may be fasten'd to the Center of the Instrument in F, to give the Axis EF a small Inclination towards C.
Transcribed by the Making Visible project
                                Related fellows
                            
                            
                                Thomas Gale (1635 - 1702, British) , Antiquary
St George Ashe (1658 - 1718, British) , Mathematician
Robert Hooke (1635 - 1703, British) , Natural philosopher
                            
                        
                            
                            
                            St George Ashe (1658 - 1718, British) , Mathematician
Robert Hooke (1635 - 1703, British) , Natural philosopher
                                Associated place