image MS_215_098
Image number: RS.16628
Credit: ©The Royal Society

A glass instrument with a bolt head


3 June 1663


Unknown, Artist

Object type

Archive reference number

Manuscript page number




height (page): 353mm
width (page): 236mm


Content object


Diagram showing experimental apparatus of a bolt-head filled with water and inverted into a small glass vessel containing enough water to cover the bottom of the stem, illustrating a paper entitled 'Of exhausting Air out of water, wch returneth into ye water againe, by Mr Hook. June 3 1663'.

This was used by Robert Hooke in an experiment using an air pump. The bubbles created by the compression were deemed to be 'rarefied water', as they disappeared two to three days after the experiment. The experiment tried at the meeting of the Royal Society on 3 June 1663 did not succeed because of leaks from the condensing machine. It was demonstrated more successfully on 10 June 1663.

This manuscript is a copy of Register Book no. 2 (RBO/2i) and some letters to the Royal Society, all from between 1662 and 1664.

The original drawing by Hooke is at Cl.P/20/19/001. Other copies of the image can be found in RBO/2ii/149, RBO/2i/227 and RBC/2/034.


There was taken a Bolt-head, holding about four ounces of water; This was filled top full with water, and the mouth of the small long stem was inserted into a small glasse vessel containing water enough, to cover about an inch of the stem, then both of them, in this posture here expressed in the figure, were shut up in a small long Receiver, out of which, when the Air had been wel exhausted there were observed to rise out of the water in the Bolt-head, abundance of small Bubbles which got up to the top, and remained there in the forms of Air, and as the Air was further exhausted out of the Reciever, the substance of those Bubbles expanded it selfe so farre as to dxine down al the water out of the Bolt-head.
Transcribed by the Making Visible project

Object history

At the meeting of the Royal Society on 3 June 1663, ‘the experiment of raising water in a kind of small weather-glass, by the pressing in of air in the condensing engine, was tried; but by reason of the engine’s leaking, proved imperfect, and was therefore ordered to be repeated at the next meeting’ (Birch 1:250).

At the next meeting, on 10 June 1663, ‘the experiment was begun to be made, to know, whether the substance of those bubbles, that are observed to float at the top of the water in two bolt-heads, after the water hath been well exhausted out of the receiver, and been re-admitted into the same, be real air, or but rarefied parts of that water. And there was put into the place of the bubble remaining in one of the bolt-heads, included in the same receiver, as much air, to see at the next meeting, whether the one as well as the other return into the pores of the water or not’ (Birch 1:254). The text and figure of this experiment are printed in Birch 1:254-55.

Related Fellows

Robert Hooke (1635-1703, British), Natural philosopher

Associated place

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