Instrument for sounding the depths of water without a line or cord
                                Date
                            
                            
                                19 March 1662
                            
                            
                        
                            
                            
                            
                                Creator
                            
                            
                                Unknown, Artist
                            
                            
                        
                            
                            
                            
                                Object type
                            
                            
                            
                        
                            
                            
                            
                                Archive reference number
                            
                            
                            
                        
                            
                            
                            
                                Manuscript page number
                            
                            
                                p3
                            
                            
                        
                            
                            
                            
                                Material
                            
                            
                            
                        
                            
                            
                            
                                Dimensions
                            
                            
                                height (page): 293mm
width (page): 185mm
                            
                        
                            
                            
                            width (page): 185mm
                                Subject
                            
                            
                            
                        
                            
                            
                            
                                Content object
                            
                            
                            
                        
                            
                            
                            
                                Description
                            
                            
                                A drawing of a wooden ball, made of maple, with a hook at the bottom, and of a cone-shaped weight with a wire to be attached to the hook underneath the ball. The ball with the weight was sunk into the water and when the weight touched the ground, the weight slipped off and the ball would ascend. By measuring the time it took for the ball to emerge, the depth of water could be measured.  
This instrument was designed by Lawrence Rooke, Fellow and Professor of Geometry at Gresham College (the first official meeting of the Royal Society was held in Rooke's rooms at Gresham College on 28 November 1660). The dimensions are of the ball and weights tested by Robert Moray and William Brouncker in March 1662. Their experiment was reported to the Royal Society on 26 March 1662 and ordered to be registered (RBO/1/152).
Other copies of the figures can be found at RBC/1/156 and MS/776/142.
                            
                            
                        
                            
                            
                            This instrument was designed by Lawrence Rooke, Fellow and Professor of Geometry at Gresham College (the first official meeting of the Royal Society was held in Rooke's rooms at Gresham College on 28 November 1660). The dimensions are of the ball and weights tested by Robert Moray and William Brouncker in March 1662. Their experiment was reported to the Royal Society on 26 March 1662 and ordered to be registered (RBO/1/152).
Other copies of the figures can be found at RBC/1/156 and MS/776/142.
                                Object history
                            
                            
                                At the meeting of the Royal Society on 8 January 1662, ‘Mr. Rooke read a paper of inquiries to be made in the East India captain’s voyage to Bantam. The method of sounding the depth of the sea was discoursed of’ (Birch 1:68). 
22 January 1662, ‘Mr. Rooke’s Directions for seamen bound for far voyages was ordered to be registered, and a copy of them to be brought to Sir Robert Moray as soon as possible, and the original to be delivered to Mr. Colwall’ (Birch 1:74).
19 March 1662, ‘The Lord viscount Brouncker gave an account of the sinking of a wooden ball in the water; and was desired with Mr. Boyle to go to the sea, and try the experiment there. It was ordered, that the amanuensis cause the wooden balls, which are to plumb the depth of the sea, to be blacked over with oily colours’ (Birch 1:78).
26 March 1662, ‘Sir Robert Moray read the following account of An experiment of the instrument for sounding of depth without a line or cord, made the 19th of March 1661/2 [1662], by the lord viscount Brouncker and himself, which was ordered to be registered and a copy of it to be sent to Trinity-House’ (Birch 1:78). The experiment is printed in Birch 1:78f. The Corporation of Trinity House of Deptford Strond was dedicated to the safety of shipping and seafarers.
                            
                        
                            
                            
                            22 January 1662, ‘Mr. Rooke’s Directions for seamen bound for far voyages was ordered to be registered, and a copy of them to be brought to Sir Robert Moray as soon as possible, and the original to be delivered to Mr. Colwall’ (Birch 1:74).
19 March 1662, ‘The Lord viscount Brouncker gave an account of the sinking of a wooden ball in the water; and was desired with Mr. Boyle to go to the sea, and try the experiment there. It was ordered, that the amanuensis cause the wooden balls, which are to plumb the depth of the sea, to be blacked over with oily colours’ (Birch 1:78).
26 March 1662, ‘Sir Robert Moray read the following account of An experiment of the instrument for sounding of depth without a line or cord, made the 19th of March 1661/2 [1662], by the lord viscount Brouncker and himself, which was ordered to be registered and a copy of it to be sent to Trinity-House’ (Birch 1:78). The experiment is printed in Birch 1:78f. The Corporation of Trinity House of Deptford Strond was dedicated to the safety of shipping and seafarers.
                                Related fellows
                            
                            
                                William Brouncker, 2nd Viscount Brouncker of Lyons (1620 - 1684, British) , Mathematician
Robert Moray (1608 - 1673, British) , Natural philosopher
                            
                        
                            
                            
                            Robert Moray (1608 - 1673, British) , Natural philosopher
                                Associated place