Dollond & Son's Pursuit of Achromaticity,1758–1789

Newton Isaac , Opticks (London, 1704), 75.

Priestley Joseph , The history and present state of discoveries relating to vision, light, and colours (London, 1772), 729; Montucla J. F. , Histoire des mathématiques, iii (Paris, 1802), 447; Herschel John , “Light”, Encyclopaedia metropolitana (London, 1827), 422.

Hutchison Keith , “Idiosyncrasy, achromatic lenses, and early Romanticism”, Centaurus, xxxiv (1991), 125–71; Sorrenson Richard , “Scientific instrument makers at the Royal Society of London”, Ph.D. Diss., Princeton University, 1993, 154–200; Nordenmark N. V. E. Nordström J. , “Om uppfinningen av den akromatiska och aplanatiska linsen”, Lychnos, iv (1938), 1–52; Nordenmark N. V. E. Nordström J. , “Om uppfinningen av den akromatiska och aplanatiska linsen”, Lychnos, v (1939), 313–84; Boegehold H. , “Zur vor- und Frügeschichte der Achromatischen Fernrohrobjective”, Forschungen zur Geschichte der Optik, iii (1943), 81–114. See also the extensive and useful bibliography in Emil Fellman, “Leonhard Eulers Stellung in der Geschichte der Optik”, in Euler Leonhard , Commentationes opticae, V, ed. by Habicht Walter Fellman Emil , Opera omnia, iii/9 (Basel, 1973), 296–322.

The most notable exception to this is Gerard Turner's entry under “Telescope (early)” in Instruments of science: An historical encylopedia , ed. by Bud Robert Warner Deborah (London, 1998). The most recent to restate Hall's priority is Willach Rolf , “New light on the invention of the achromatic telescope objective”, Notes and records of the Royal Society of London , 1 (1996), 195–210. See among many others: Chap. 9 in King Henry , History of the telescope (London, 1955); Daumas Maurice , Scientific instruments of the seventeenth and eighteenth centuries and their makers, transl. by Holbrook M. (London, 1989), 153–6; Herschel , op. cit. (ref. 2), 411. See also Barty-King Hugh , Eyes right: The story of Dollond & Aitchison, 1750–1985 (London, 1986), which was commissioned by Dollond & Aitchison and is unfortunately not at all scholarly. Another disputed optical invention, the single object lens telescope itself, has received much more careful examination. For an exemplary review of the literature and analysis of the lens itself see Van Helden Albert , “The historical problem of the invention of the telescope”, History of science, xiii (1975), 251–63.

Deiman J. C. , “Optics and optical instruments, 1600–1800”, in Companion encyclopedia of the history and philosophy of the mathematical sciences, ed. by Grattan-Guinness I. (New York, 1994), 1159–60.

This was Newton's final public claim. Earlier in his life, he had thought an achromatic lens might be possible, but had never been able to make one. Even sympathetic commentators concede that Experiment VIII in Part 2 of Book I (hereafter Experiment VIII) was to some degree a “fabrication”. See Shapiro Alan , “Newton's ‘Achromatic’ Dispersion Law: Theoretical background and experimental evidence”, Archive for the history of the exact sciences, xxi (1979), 91–128, pp. 126–7.

Euler Leonhard , “Sur la perfection des verres objectifs des lunettes [1747]”, in Commentationes opticae, II , ed. by Cherbuliez Emil Speiser Andreas , Opera omnia, iii/6 (Basel, 1962), 1–21, p. 13.

See the entry under “Eye” in Encylopaedia britannica, 11th edn (Edinburgh, 1911).

See entries under “Short, James” and “Dollond, John (I)” in Clifton Gloria , Directory of British scientific instrument makers, 1550–1851 (London, 1995).

Kelly John , The life of John Dollond, FRS, inventor of the achromatic telescope (London, 1808), 6–7. Kelly was a son-in-law of Peter Dollond.

While there is no specific trace of John Dollond in the records of the Spitalfields Mathematical Society (Larry Stewart, personal communication) it seems highly likely he had some contact with it given the Society's strong Huguenot associations and its location in Spitalfields. For an excellent account of the kinds of experimental and mathematical activities undertaken by intelligent artisans and merchants in Spitalfields in the eighteenth century see Stewart Larry Weindling Paul , “Philosophical threads: Natural philosophy and public experiment among the weavers of Spitalfields”, The British journal for the history of science, xxviii (1995), 37–62.

Dollond John , “A letter to James Short concerning a mistake in Mr. Euler's theorem for correcting the aberrations in the object-glasses of refracting telescopes”, Philosophical transactions, xlviii (1753), 289–91.

See the entry “Dollond, Peter”, in Clifton , op. cit. (ref. 9). The partnership was also known as P. & J. Dollond. Most practical opticians in the City of London belonged to the Spectaclemakers' Company which was founded comparatively late, in 1629. Brown Joyce , “Guild organization and the instrument-making trade, 1550–1830”, Annals of science, xxxvi (1979), 1–34, p. 8.

“An Account of Mr. Klinginstierna's Paper entitled Considerati circa Legem Refractionis Radiorum Luminis Diversi Generis in Mediis Diversis. Vid. Newt: Opt., Lib. I. Part II. Prop. 3. Exp. 8”, read by James Short at the Royal Society, 16 April 1761, Royal Society of London, Letters and Papers (hereafter RSL&P), IV.66. Quotations from this and subsequent Royal Society manuscripts are used by permission of the President and the Council of the Royal Society. The mean ray is a coloured ray of light from the middle of the spectrum.

Dollond John , “An account of some experiments concerning the different refrangibility of light”, Philosophical transactions, 1 (1758), 733–43, pp. 738, 736.

For example, the Swedish astronomer, Bengt Ferrner, purchased two telescopes in 1760 on a visit to London. The first, which cost £7.7.0, was for the Royal Swedish Academy of Sciences, and the second for Klingenstierna, who urgently wanted to use, inspect, and have copied the lens he had helped bring into being. The Swedish Academy also has two other Dollond achromats, one of which was the personal property of the Swedish King. Pipping Gunnar , The chamber of physics: Instruments in the history of sciences collections of the Royal Swedish Academy of Sciences, Stockholm (Uppsala, 1991), 101–3. The Duke of Orleans had a Dollond achromatic telescope valued at 1,400 livres [£70] in his collection, Daumas, op. cit. (ref. 4), 145. For the attempts to mathematize the discovery, see Hutchison , op. cit. (ref. 3).

Macclesfield Lord , President of the Royal Society, Copley Medal speech, Royal Society of London, Journal Book (hereafter RSJB), 30 November 1758.

For another example of a similar ploy, but with rather different aims, see Biagioli Mario , “Replication or monopoly? The economies of invention and discovery in Galileo's observations of 1610”, Science in context (forthcoming).

Dollond , op. cit. (ref. 12). The theorem was published after John Dollond's death in Maskelyne Nevil , “A theorem of the aberration of the rays of light refracted through a lens, on account of the imperfection of the spherical figure”, Philosophical transactions, lii (1761), 17–21.

For the Royal Society's earlier, failed, attempts at investigating trade secrets see Ochs Kathleen , “The Royal Society of London's History of Trades”, Notes and records of the Royal Society of London, xxxix (1985), 129–58.

See especially Part 3, Chapter 7 (“Theorems for finding focal distances of compound lenses”) and Chapter 8 (“Remarks on the nature, and construction, and effects of the foregoing achromatic telescope”) in Martin Benjamin , New elements of optics; or, the theory of the aberrations, dissipation, and colours of light (London, 1759), 79–87. Willach has examined a French copy of a Dollond lens in the Louvre that is dated December 1760 (signed on the objective mount “Inventum Dollondi. Detixit Passemant mense X^bre 1760”). It is significantly inferior to Dollond lenses of the same time period. Rolf Willach, personal communication. Passemant worked in the King's workshop in the Louvre. Daumas , op. cit. (ref. 4), 99.

Dollond Peter , “An Answer to a Paper Presented to the Royal Society by Mr. Jesse Ramsden Relating to the Invention of the Achromatic Telescope”, manuscript, in RSL&P, IX. 146.

Public Record Office, London (hereafter PRO), S07/233.

Figure 8, Plate 4 in Martin, op. cit. (ref. 21).

Willach , who argues that Dollond copied this arrangement from opticians who worked for or were inspired by Hall, has analysed, but not dated, three FFS achromats signed by James Ayscough, Joseph Linnell, and John Dollond ( Willach , op. cit. (ref. 4), 199–205). However, only the Dollond can be reliably dated to c. 1758, since the documentary evidence for Dollond's producing an achromatic lens in 1758, or even late 1757, is overwhelming and outlined above. The Linnell lens must postdate 1758, as Linnell did not have his own workshop until 1764. And while Ayscough died in 1759, his widow kept trading under his name until 1767; therefore, a lens signed “Ayscough” could have been made as late as 1767. These three lenses, until firmly dated, cannot demonstrate either a Dollond or a Hall (via Ayscough) priority. See the entries under “Linnell, Joseph”, and “Ayscough, James” in Clifton, op. cit. (ref. 9).

Watkins Francis , PRO C12/1956/19. Obtaining an eighteenth-century English patent cost approximately £70 in charges and stamp duties to a variety of government offices and often as much again in other fees to officials and solicitors who helped navigate the application through those offices in the correct order. Following upon that were the extensive and open-ended expenses of defending the patent if it were (as it usually was) infringed. Macleod Christine , Inventing the industrial revolution: The English patent system, 1660–1800 (Cambridge, 1988), 76–77. This kind of expenditure was completely beyond someone who relied on wage labour alone; additional capital had to come from loans, shares (partnership or stockholder), or profits. A farm labourer or common servant might earn £20 per year in wages and perquisites while £40 a year was a good wage for a skilled London artisan in the middle of the eighteenth century. See idem, chap. 5, 75–96, “The decision to patent” for a general set of explanations as to why someone like Dollond and Watkins undertook to obtain a patent.

Millburn John , Adams of Fleet Street, Instrument Makers to King George III (Aldershot, 1999), 62–66.

Ramsden Jesse received a portion of the patent when he married Peter's sister, Sarah. See the entry under “Ramsden” in Dictionary of national biography (Oxford, 1920–21). Peter took charge of the business and all aspects of the patent trial. Peter was the “Administrator” of the estate (PRO C33/427) and gives a brief description of the dispute between himself and Watkins and the purchase of Watkins's share in the patent in: Peter Dollond to the Lord Chancellor, 12 July 1765, PRO C12/1956/19.

Its asphericity had been earlier commented on in Kiltz G. , “Untersuchung Zweier von Dollond und Ramsden Hergestellter Fernrohrobjective”, Zeitschrift für Instrumentenkunde, lxii (1942), 41–46.

Willach , op. cit. (ref. 4), 205–8.

Even before the patent trial, Peter Dollond sold achromatic refractors “at a much higher rate than that what they have always been sold at by others in the Trade”, according to one of the opticians sued by him, Christopher Steadman, in 1765; PRO C12/1956/19. For a price list that shows that Peter Dollond raised his price substantially after he successfully defended his patent, see Robischon Mary , “Instrument makers in London during the seventeenth and eighteenth centuries”, Ph.D. Diss., Michigan, 1983, 292.

Watkins Francis , the Dollonds' former partner, asserted in 1765 that Peter Dollond's profit margin was at least 200%, leading to a minimum annual profit of £800, PRO C12/1956/19.

Macleod , op. cit. (ref. 26), 61. Beyond a brief mention of the case, she does not otherwise investigate it.

Macleod , op. cit. (ref. 26), 7.

PRO SO7/233.

Robischon , op. cit. (ref. 31), 300–2.

PRO PC1/7 n.94, received 22 June 1764. The petition was signed by 34 instrument makers, mainly optical instrument makers. It was supported by the Spectaclemakers' Company. Two well-known mathematical instrument makers, Troughton John Bird John , also signed the petition.

The Privy Council no longer regulated patents after 1753. Macleod , op. cit. (ref. 26), 73, 66.

Brown , op. cit. (ref. 13); Thompson E. P. , The making of the English working class (Harmondsworth, 1968), 595.

The records of these trials at the London Public Record Office are not complete. The most extensive are a series of depositions, dated October and November 1765, in the Chancery Court (PRO C12/1956/19). Peter Dollond seems to have gone to Chancery to enforce an earlier judgement in his favour at King's Bench, 12 July 1764, before Lord Mansfield. The defendants before Mansfield were William Eastland, Francis Watkins, Addison Smith, James Champneys and Christopher Steadman. Dollond was still trying to enforce the judgement in July 1767 (PRO C33/427/296). Dollond won another court case before Lord Camden at Common Pleas, in February 1766. The defendant there was James Champneys, see The gazetteer and new daily advertiser, 20 February 1766.

Watkins Francis , PRO C12/1956/19.

Until the second half of the eighteenth century, patents were very unusual in the instrument-making trade in general and were actively opposed by the Spectaclemakers' Company in particular. They became more common as the influence of the guilds waned. Macleod, op. cit. (ref. 26), 113, 137.

Bird John , witness before Lord Camden, Common Pleas, 1766. This testimony was recalled in Dollond, op. cit. (ref. 22).

Champneys James , 29 October 1765; Watkins, Smith, Eastland and Steadman use very similar language, in PRO C12/1956/19.

Hall is called this in Nordenmark and Nordström, op. cit. (ref. 3), 380.

The most recent supporter of his claim, Willach Rolf , admits that “we have very little knowledge of him…. Hall never published any information about his research on the achromatic object glass. The only written documents to survive him are some signatures on judicial files.” Willach , op. cit. (ref. 4), 195.

Steadman Christopher , 1765, PRO C12/1956/19.

Smith Addison , PRO C12/1956/19.

Dollond , op. cit. (ref. 22).

In another case, before Lord Camden, James Champneys was ordered to pay £150 in damages. The gazetteer and new daily advertiser, 20 February 1766.

King , op. cit. (ref. 4), 158–9. Reputation alone could last for a very long time. Albert van Helden notes that Galileo's reputation as a pre-eminent telescope maker lasted until his death, even though others had probably surpassed him by 1612, in Van Helden Albert , “Telescopes and authority from Galileo to Cassini”, Osiris, n.s., ix (1994), 9–29, p. 18. There are hundreds of Dollond CFA achromats surviving today, Willach Rolf , personal communication. Dollond & Son probably did not dominate the spyglass portion of the refracting telescope trade after 1772, Deborah Warner, personal communication. While flint glass was widely available in London, large pieces of high quality flint glass (free of bubbles and cracks) were rarer and very expensive. King , op. cit. (ref. 4), chap. 9.

Drake Stillman makes exactly the same point about Isaac Beeckman's reporting of Johannes Zachariassen's claim that his father invented the telescope. “The credence due to Beeckman, a highly intelligent and upright man, has been unreasonably transferred to the story he heard from Johannes [Zachariassen]”. Drake Stillman , Galileo studies: Personality, tradition, and revolution (Ann Arbor, 1970), 155–6.

Smith Addison , in a letter to Ramsden, 4 June 1789, quoted in Ramsden Jesse , “Some Observations on the Invention of the Achromatic Telescopes”, manuscript, in RSL&P, IX. 138 (1789).

Again , the parallel with the dispute over who invented the first telescope in the seventeenth century is remarkable, in that there was probably a lens/eyepiece system as early as 1590 (well before the Dutch patent application of 1608) but that its magnification was so low that no one took much notice of it, or wanted to copy it. However, much later, at least one claimant, Johannes Zachariassen, then referred to this earlier device as having been invented by his father, thereby laying claim to the invention of the telescope. Helden Van , op. cit. (ref. 4), 256–9.

Willach Rolf , “The early history of the achromatic telescope objective”, Journal of the Antique Telescope Society, xii (1997), 4–13, p. 5.

Watkins Francis , in a letter to Ramsden, c. 1789, quoted in Ramsden , op. cit. (ref. 53).

Dollond , op. cit. (ref. 22).

Dollond Peter , “Some Account of the Discovery Which Led to the Grand Improvement of Refracting Telescopes Made by the Late Mr. John Dollond FRS in Order to Correct Some Misrepresentations in Foreign Publications of That Discovery”, manuscript, in RSL&P, IX. 131 (1789).

Ramsden , op. cit. (ref. 53).

Dollond , op. cit. (ref. 22).

Widmalm Sven , “Accuracy, rhetoric, and technology: The Paris–Greenwich triangulation, 1784–1788”, in The quantifying spirit in the eighteenth century, ed. by Frängsmyr Tore (Berkeley and Los Angeles, 1990), 179–206.

Roy William , RSJB, 25 February 1790.

Ramsden Jesse to the Council of the Royal Society, 13 May 1790, Royal Society of London, Domestic Manuscripts, 4.44.

13 May 1790, Royal Society of London, Miscellaneous Manuscripts, 3.30.

Banks Joseph Sir , Copley Medal presidential address, RSJB, 30 November 1795.

Dollond , op. cit. (ref. 22).

Dollond Peter did have a patron at the Royal Society, the Astronomer Royal, Nevil Maskelyne, who sponsored both of his 1789 letters, but Maskelyne had been one of the leaders of the opposition to Banks in the “dissensions” five years earlier at the Royal Society, which lessened his influence subsequently with Banks. Heilbron John , “A mathematicians mutiny, with morals,” in World changes: Thomas Kuhn and the nature of science, ed. by Horwich Paul (Cambridge, Massachusetts, 1993), 81–129.

Ramsden Jesse , Gentleman's magazine (London), 30 September 1790, 890–1, is very similar to the letter that Ramsden sent to the Royal Society the year before; Dollond Peter , Some account of the discovery made by the later Mr. John Dollond FRS which led to the grand improvement of refracting telescopes…. With an attempt to account for the mistake in an experiment by Sir Isaac Newton (London, 1789).

Sorrenson Until , op. cit. (ref. 3), 177; Bennett J. A. , “Peter Dollond answers Jesse Ramsden”, Sphaera, viii (1998), 4–5.

Shapin Steven , A social history of truth: Civility and science in seventeenth century England (Chicago, 1994).

Merton Robert , “Priorities in scientific discoveries”, in The sociology of science: Theoretical and empirical investigations (Chicago, 1973).

Dollond , op. cit. (ref. 22).

Dollond , op. cit. (ref. 22).