Newton and the Royal Society

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Debating Newton at the Royal Society

 

Edward Worth was elected a Fellow of the Royal Society on 11 January 1699. Although he was not an active member of the Society this should not be taken as an indication of any lack of interest on his part. Worth was quite clearly entranced by all things scientific and was particularly interested in the publications of the Society’s members, both individual publications and their papers delivered to the Society. The motto of the Royal Society, ‘Nullius in verba’ (take nobody’s word for it’), with its emphasis on experiment, runs through Worth’s entire collection of scientific works.

Phil. Trans to 1700 titlepage.

Six years after his election as a fellow the Royal Society published its first abridgment of the Philosophical Transactions which Worth duly bought in a second edition of 1716. This first abridgment of the Philosophical Transactions had initially been suggested in May 1703 and came to the press two years later with the imprimatur of Newton. The editor, John Lowthorp, explained his target audiences in the following terms: ‘When I first Resolv’d upon this Undertaking, I had Two Sorts of Readers in View, whom I was desirous to serve; those who make use of Books for their Private Instruction or Entertainment, and those who Consult them in order to Publish something of Their Own’. Worth’s decision to purchase the abridgment may have had something to do with the availability of the original individual journals. Kronick (1990) points out that some of the issues may have been difficult to acquire. Samuel Johnson’s letter to John Lowthorp in 1739 (quoted in Kronick), ruefully stated ‘How few will read or purchase forty-four large volumes of the Transactions of the Royal Society, which in abridgment, are generally read to the improvement of philosophy.’ The abridgments thus provided a popular access point to the deliberations of the Society. In fact Worth purchased the two abridgments which came on the market during his lifetime (the third, which came out in 1733, was published after his death). His choice of the second edition of the Philosophical Transactions to 1700 may have been due to a scarcity of the initial edition, which, as Kronick (1990) reports, was scarce by the 1750s.

Phil. Trans to 1720 titlepage;

Philosophical Transactions Bindings.

It is clear that the 1720 publication carried on where the first abridgement as far as 1700 left off. This is apparent not only in the above titlepages to the works but also in the numbering on the spines on the bindings of Worth’s copies. Volumes 1-3 cover the period up to 1700 and are divided into volume 1, which dealt with mathematical papers; volume 2 with physiological and volume 3 with anatomical, medical, chymical, philological and miscellanous papers. Volume IV (i.e. the first of the 1721 edition of papers from 1700 to 1720), began again with mathematical and physiological papers while volume V continued on with Lowthorp’s arrrangment. As

Henry Jones, the 1721 editor, explains, this was an editorial decision taken because readers were already familiar with Lowthorp’s method which was ‘very well Receiv’d in the World’.

It is clear, though, that some areas received more investigation than others, while some afforded greater opportunities for experimentation. The latter was the case with optics. Sorrenson (1996) notes that many of the Newtonian experiments undertaken by the fellows of the Royal Society focused on replicating those in Newton’s Opticks. The following account of experiments, undertaken by John Theophilus Desaguliers, is taken from Worth’s abridgment of the Philosophical Transactions to 1720. As curator of experiments Desaguliers was one of the major contributors to the Philosophical Transactions. Rupert Hall (1971) states that between 1716 and 1742 he contributed fifty-two papers to it. Many of Desaguliers’ experiments at the Royal Society (particularly prior to Newton’s death in 1727) were undertaken to refute charges that Newton’s theories were unverifiable. In particular, the experiments which Desaguliers undertook in the field of optics sought to prove to French critics that Newton’s optical experiments worked and were capable of verification.

 

Desaguliers cited in Philosophical Transactions to 1720, p. 173.

 

Some of Sir Isaac Newton’s Experiments of Light, & Colours repeated,

by Mr. J. T. Desaguliers.

‘Sir Isaac Newton therefore, upon reading what had been cited out of the Acta Eruditorum, desired Mr. Desaguliers to try the Experiment in the manner described in the said Proposition; and he tried it accordingly with Success before several Gentlemen of the Royal Society, and afterwards before Monsieur Monmort and others of the Royal Academy of Sciences; How this and other concomitant Experiments were tried and succeeded, is described as follows.

Experiment I. Having sew’d together end wise two Pieces of Ribbon four Inches long each, the one Blew and the other Red, whose common Breath was ¼ of an Inch; I caus’d it to be held in such manner, that the Light which fell from the Clouds thro’ the Window was so reflected, that the Angle made by the Rays of Light, which came in at the Middle of the Window, with the Plane of the Ribbon produced, was equal to the Angle made by a Line drawn from the Ribbon to my Eye, and the said Plane of the Ribbon. My Eye was plac’d as far behind the Ribbon as the Window was before it, the Distance from which to me was about 12 Feet. Then looking thro’ a Prism at the Ribbon, it appear’d broken asunder in the Place where the blew and red Half join’d. If the Prism was held with the refracting Angle downwards (or laid with one of its Planes flat upon the Nose) the blew Half of the Ribbon appear’d to be carried down lower than the red, as at B, R, but if the refracting Angle of the Prism was turn’d upwards (as when the Prism has one of its Planes laid flat to the Forehead) then the blew Half of the Ribbon was lifted up, as at βρ.

The Prism was of white Glass, having every Angle of 60 Degrees: but when instead of it, one of the greenish Sort of Glass, such as Object Glasses of Telescopes are made of, was used, having the refracting Angle which I look’d thro’ of about 48 Degrees; the same Phaenomenon was more distinct, this Glass having no Veins, but the Red and Blue were nearer to a straight Line: in such Manner that if A represent the Ribbon seen through the first Prism, B will represent the Ribbon seen through the second Prism, Fig 37. If the refracting Angle of the last Prism had been as great as that of the first, the Light being transmitted through too great a Body of greenish Glass, the Phaenomenon would not have succeeded so well.

The blue Ribbon being somewhat too pale, and the red a little dull; I repeated the Experiment with a Skeen of blue, and one of red Worsted join’d together in the Middle as the Ribbon were before; and the Colours of both being very intense, the Experiment succeeded better with both Prisms. All that were present trying the Experiment found it to succeed, and that every Circumstance answer’d to the Account given in Prop. I. Theor.1 Book I. of Sir Isaac Newton’s Optics, as far as the Directions there given were followed. So that it appeared that the blue being carried lower than the red in the first Case, and lifted higher in the second, was owing to the greater Refraction of the blue Ray: For though each Part of the Ribbon or Worsted reflected all manner of Rays, yet the Phaenomenon was very apparent; as also that the blue Ribbon or Worsted reflected the red Rays more than the blue ones, because the red of the blue Half seen through the Prism was less intense than that of the red Half, and the blue or Purple of the red Half seen through the Prism was less intense than that of the blue Half.

N.B. If the Ribbon or Worsted is laid upon any enlightened Body, the Phaenomenon will not succeed so well; the Colours of the Body seen through the Prism mixing with those of the Ribbon or Worsted. Even a Black Body will not do, if Light falls upon it: But there must be a black Cloath behind, in such manner that no Light falling upon it can be reflected so as to disturb the Phaenomenon. And if a short-sighted Person looks through the Prism, a Concave-Lens between his Eye and the Prism, will render the Phaenomenon more distinct than it would otherwise be.

Exp. 2] Some Days after the Sun shining, I made two Holes H, h, in the Window Shut S s, of a darkned Room; through which letting the Sun’s Beam pass, by means of two Prisms A, B (one near each Hole) I opened the Rays coming from the Sun into the two colour’d Spectra α, β, where the following Colours were very distinct, viz. Red, Orange, Yellow, Green, Blue, Purple and Violet. Now the Reason of their being more distinct than ordinary, was, that the Prisms which I made use of, were made of the greenish Glass mentioned before; which is very free from those Veins by which the Colours are too much thrown into one another, by the best white Prisms of the common sort.

The forementioned coloured Spectra being thrown into the Room, to the Distance of about 20 Feet from the Window where the Sun’s Light came in, I caused a Piece of white Paper π, ¾ Inch broad and 5 Inches long, to be held within the refracted Rays, (at the Distance of 10 Feet from the Windows,) which produced these Colours in such manner, that by turning the Prisms round their Axes, I could make the red Ray of the Spectrum made by the one Prism, fall upon one half of the Paper, and the purple Ray of the Spectrum made by the other Prism fall upon the other Half; for the Spectra were both vertical, the Lines which terminated the long Sides of them towards each other just touching, as appears in Fig .38. Then at the Distance of 9 Foot, looking through the Prism C at the Paper thus coloured, the red Half appeared very much separated from the Purple appearing the highest, according as the refracting Angle of the Prism was either held upwards or downwards. The Phaenomenon is much more distinct this Way than any other; for the Paper not only seems divided into two, when it is coloured by a red and purple Ray (Fig. 40) or indeed by any two Colours that are different, how near soever their Places in the Spectra to be each other. The Halves of the Paper appear, when viewed through the Prism, to be farther from each other, when the Paper is tinged with such Colours as are farther from each other in the Series of Colours in the Spectrum; and nearest, though still divided, when neighbouring Colours fall upon the Paper, as Yellow and Green, or a light and a deep Green. But the Paper appears no way divided, when coloured with the Red of the two Spectra (Fig 41) if those Reds are equally intense; and so of the other Colours.’

Detail of Plate 3

The similarity between some of Desaguliers’ experiments in the journals of the Royal Society and those in his experimental philosophy lecturing course in London is not surprising – the experimental world of Georgian London was very close knit. As a fellow of the Royal Society Desaguliers could move easily between the two spheres while men like William Whiston, although he was denied fellowship of the Royal Society, was an equally visible figure to the fellowship because his own lectures took place in a coffee house in the same street as the Royal Society.

 

Worth’s signature on Sprat’s The History of the Royal Society of London (London, 1667).

 

Sources

Fara, Patricia (2004), ‘Desaguliers, John Theophilus (1683–1744)’, Oxford Dictionary of National Biography, Oxford University Press.

Hall, A. Rupert (1971) ‘Desaguliers’, Dictionary of Scientific Biography (New York), IV, pp.43-6.

Kronick, David A. (1990), ‘Notes on the Printing History of the Early ‘Philosophical Transactions’, Libraries and Cultures 25, no. 2, pp. 243-268.

Pumfrey, Stephen (1995), ‘Who did the work? Experimental Philosophers and Public Demonstrators in Augustan England’, The British Journal for the History of Science 28, no. 2, pp. 131-56.

Sorrenson, Richard (1996), ‘Towards a History of the Royal Society in the Eighteenth Century’, Notes and Records of the Royal Society of London 50, no. 1, pp. 29-46.

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