Modification to Hooke's design of a pocket-sized level
Date
27 May 1686
Object type
Archive reference number
Manuscript page number
p339
Material
Dimensions
height (page): 320mm
width (page): 197mm
width (page): 197mm
Subject
Content object
Description
A small figure showing how a wire should be fastened to a pin in the centre by a small thread (so as not to touch the pin), in Robert Hooke's design of a pocket-size level. From a letter by Edmond Halley addressed to William Molyneux at the Dublin Philosophical Society dated 27 May 1686. Molyneux, in his reply dated 19 June 1686 to Halley, wrote that he did not quite understand the instruction (see LBO/10/319, where the figure is reproduced).
Transcription
I doubt not but you have seen the account I sent Mr Ashe about Mr Hooke's Level. Mr Ashe writes us, the consideration thereof was refer'd to you, and that you reported favourable of it: only it was found somewhat ticklish, and would hardly ever come to the same Point twice, tho' the Instrument were unmoved. This Mr Hooke believes to have proceeded from the want of a Contrivance, which I forgot to mention in the Letter sent to you, viz: that the Wire, on which the Weight is fixt, was to be fasten'd to the Pin in the Center by a small Thread, as in the margin [image]; and not to touch the said Pin at no time: and he is positive, that when this is done you will find this Objection cease.
Transcribed by the Making Visible project
Transcribed by the Making Visible project
Related fellows
Edmond Halley (1656 - 1742, British) , Astronomer
William Molyneux (1656 - 1698, British) , Science writer
Robert Hooke (1635 - 1703, British) , Natural philosopher
William Molyneux (1656 - 1698, British) , Science writer
Robert Hooke (1635 - 1703, British) , Natural philosopher
Associated place