Instrument for sounding the depths of water without a line
Date
19 March 1662
Creator
Unknown, Artist
Object type
Archive reference number
Manuscript page number
p152
Material
Dimensions
height (page): 367mm
width (page): 299mm
width (page): 299mm
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 and the weight were sunk into the water and when the weight touched the ground it 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 Society on 26 March 1662 (Cl.P/19/7) and was ordered to be registered.
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 Society on 26 March 1662 (Cl.P/19/7) and was ordered to be registered.
Transcription
The Globe was of Mapple [sic] wood, 5 13/16 inches in Diameter, weighing 2 1/4 ll having in it a hook of iron for bearing of the lead.
The Lead of a conicall figure 11 inches long, 1 9/16 inche at the top and 9/16 inch at bottome, in Diameter, with a wire at top making an angle of some 60 Degrees, with the side of the Lead, which weighed 4 1/2 ll.
The Depth of the water being about 19 foot; Betweene the immersion of the Globe and emersion thereof there intervened uppon reiterated tryalls still 6 seconds of an houre measured by a second watch.
At the Depth of about 10 foot, there intervened constantly 3 1/2 second or thereabouts.
They found no difference in time of the submersions of the Globe, at the greatest depth, when it rose some two wherries lengths from the place where it was let fall, (being carried by the current of the tide) and when it rose within a yard or so of the same place where it was let fall.
The Wood Globe did alwayes rise quite above the superfice of the water when it was let fall at the greatest depth.
The Globe being put into a water without the weight, the superfice of the water cover'd it to about 2/3 of the Diameter.
Transcribed by the Making Visible project
The Lead of a conicall figure 11 inches long, 1 9/16 inche at the top and 9/16 inch at bottome, in Diameter, with a wire at top making an angle of some 60 Degrees, with the side of the Lead, which weighed 4 1/2 ll.
The Depth of the water being about 19 foot; Betweene the immersion of the Globe and emersion thereof there intervened uppon reiterated tryalls still 6 seconds of an houre measured by a second watch.
At the Depth of about 10 foot, there intervened constantly 3 1/2 second or thereabouts.
They found no difference in time of the submersions of the Globe, at the greatest depth, when it rose some two wherries lengths from the place where it was let fall, (being carried by the current of the tide) and when it rose within a yard or so of the same place where it was let fall.
The Wood Globe did alwayes rise quite above the superfice of the water when it was let fall at the greatest depth.
The Globe being put into a water without the weight, the superfice of the water cover'd it to about 2/3 of the Diameter.
Transcribed by the Making Visible project
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 1:78-79. 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 1:78-79. The Corporation of Trinity House of Deptford Strond was dedicated to the safety of shipping and seafarers.
Related fellows
Robert Moray (1608 - 1673, British) , Natural philosopher
William Brouncker, 2nd Viscount Brouncker of Lyons (1620 - 1684, British) , Mathematician
Lawrence Rooke (1622 - 1662, British) , Astronomer
William Brouncker, 2nd Viscount Brouncker of Lyons (1620 - 1684, British) , Mathematician
Lawrence Rooke (1622 - 1662, British) , Astronomer
Associated place