Glass balls
                                Date
                            
                            
                                26 November 1662
                            
                            
                        
                            
                            
                            
                                Creator
                            
                            
                                Unknown, Artist
                            
                            
                        
                            
                            
                            
                                After
                            
                            
                                Robert Hooke (1635 - 1703, British) , Natural philosopher
                            
                            
                        
                            
                            
                            
                                Object type
                            
                            
                            
                        
                            
                            
                            
                                Archive reference number
                            
                            
                            
                        
                            
                            
                            
                                Manuscript page number
                            
                            
                                p40
                            
                            
                        
                            
                            
                            
                                Material
                            
                            
                            
                        
                            
                            
                            
                                Dimensions
                            
                            
                                height (page): 350mm
width (page): 230mm
                            
                        
                            
                            
                            width (page): 230mm
                                Subject
                            
                            
                            
                        
                            
                            
                            
                                Content object
                            
                            
                            
                        
                            
                            
                            
                                Description
                            
                            
                                Drawing of a double glass ball used by Robert Hooke to prove compression of air in the internal glass ball. This was reported among other experiments using glass balls to the meeting of the Royal Society on 26 November 1662. 
ABC shows a glass ball made of white glass melted in the flame of a lamp and sealed up while the ball was very hot. DFEIK indicates a bolt head cut off at IK to fit in the ball and sealed up with cement afterwards. Water was then poured in between the bolt head and the glass ball until it reached H. When the top of the glass ball, A, was broken, the height of the water rose to G (1/8 of an inch), which indicates the measure of the air that was compressed in the glass ball ABC.
The original drawing by Hooke is at Cl.P/20/3/003. Copies of this image are found in Cl.P/24/51/003, RBO/2ii/044, RBC/1/261 and MS/776/239.
                            
                            
                        
                            
                            
                            ABC shows a glass ball made of white glass melted in the flame of a lamp and sealed up while the ball was very hot. DFEIK indicates a bolt head cut off at IK to fit in the ball and sealed up with cement afterwards. Water was then poured in between the bolt head and the glass ball until it reached H. When the top of the glass ball, A, was broken, the height of the water rose to G (1/8 of an inch), which indicates the measure of the air that was compressed in the glass ball ABC.
The original drawing by Hooke is at Cl.P/20/3/003. Copies of this image are found in Cl.P/24/51/003, RBO/2ii/044, RBC/1/261 and MS/776/239.
                                Object history
                            
                            
                                26 November 1662, ‘Mr. Hooke brought in his account of the experiments tried with glass-balls’ (Birch 1:127).
                            
                            
                        
                            
                            
                            
                                Related fellows
                            
                            
                                Robert Hooke (1635 - 1703, British) , Natural philosopher
                            
                            
                        
                            
                            
                            
                                Associated place