Design of a comparative weighing scale
Date
16 January 1684
Creator
Unknown, Artist
Object type
Archive reference number
Manuscript page number
p141
Material
Dimensions
height (page): 365mm
width (page): 230mm
width (page): 230mm
Subject
Content object
Description
Robert Hooke's design of scales placed on cross beams. Hooke produced a model at the meeting on 16 January 1684, but it was judged as inaccurate.
Transcription
Let AC, BD, represent the Cross Beam, moving on I, the Scales hanging at A and B. The Weights being put, the heavier in B, the lighter in A, the Cross positeth itself as in the Scheme in respect of the horizontal Line EF, and the Perpendicular GH; and their comparative Weight is found by their several Distances from the Perpendicular IH, that is, as BN to AM, so the Weight at A, to the Weight at B. Thus far is clear from the Principle in Staticks. Let KP represent the Plumb Line, suspended at K; I say then, that IK is to IL, as BN is to AM, or, as the lesser to the bigger Weight, for AM, is equal to IN, and the Angle NIL, is equal to IILK, therefore KIL, so BN to NI = to AM, so the Weight at A to the Weight at B. Q.E.D.
Transcribed by the Making Visible project
Transcribed by the Making Visible project
Object history
Hooke was absent at the beginning of the meeting on 16 January 1684, but it seems that he attended later, as it is recorded that he ‘shewed a way how to give the proportions of two weights one to another, the apparatus being not designed for an accurate trial’ (Birch 4:250).
The paper with the figure is printed in Robert Hooke, Philosophical Experiments and Observations, ed. by W. Derham (London: 1726), pp. 121-22.
The paper with the figure is printed in Robert Hooke, Philosophical Experiments and Observations, ed. by W. Derham (London: 1726), pp. 121-22.
Related fellows
Robert Hooke (1635 - 1703, British) , Natural philosopher
Associated place