Herschel's 40ft Reflector: Funding and Functions

From Herschel's 1785 letter to Joseph Banks Sir (for the King) requesting funding for the 40ft, see Appendix 1.

From the original typescript for The Herschel chronicle by Constance Lubbock A. (Cambridge, 1933), XII, 35. In what follows, Chronicle followed by an arabic numeral refers to a page in the published version, while Chronicle followed by upper-case roman and then arabic refers to the typescript by chapter and page. I am very grateful to the owners, The William Herschel Society, of 19 New King Street, Bath, for making this invaluable source available to me.

William Herschel [hereafter: WH], “Astronomical observations relating to the construction of the heavens”, Philosophical transactions [hereafter: PT], ci (1811), 269–336, p. 269.

RAS MS Herschel W.5/12.1, pp. 48ff (see the catalogue by Bennett J. A. , Memoirs of the Royal Astronomical Society , lxxxv (1978)); Chronicle , 88–90.

On this and all of Herschel's telescopes, see the classic article by Bennett J. A. , “‘On the power of penetrating into space’: The telescopes of William Herschel”, Journal for the history of astronomy , vii (1976), 75–108.

The literature on this is immense. See for example Bennett J. A. , “Herschel's scientific apprenticeship and the discovery of Uranus”, in Uranus and the outer planets , ed. by Garry Hunt (Cambridge, 1982), 35–53.

On this see Chronicle , 112 seq.

Chronicle , VI, 6–7.

Chronicle , 113.

“A letter from William Herschel, Esq., F.R.S.”, PT , lxxiii (1783), 1–3.

Letter from Demainbray Herschel , 12 August 1781, W.1/13.D.14: “His Majesty informed me last Friday, that you believed you had discovered a Comet, and that you intended to come to Richmond, to ascertain its cituation with some of our fixed instruments.” Herschel is most welcome, but if he cannot come to Kew, please will he notify Demainbray of “the situation nearly of your Comet or Planet”..

Chronicle , 112–13.

Caroline Lady Herschel (wife of Caroline's niece John) dated 3 February 1842, Memoir and correspondence of Caroline Herschel , by Mrs John Herschel (2nd edn, London, 1879; hereafter: Memoir ), 320–2.

Chronicle , 114–18.

George Griesbach (1757–1824) joined the band in May 1778, his brother Henry (1762–1832) in 1780, and Frederick (1769–1825) and William (1772–) followed suit in the next few years ( Chronicle , VI, appendix by George Griesbach Philip H. Highfill , A biographical dictionary of actors …, vi (Carbondale and Edwardsville, 1978)). They must have added to the gaiety of nations as they went about in scarlet coat, waistcoat and breeches, cocked hat, and sword. Charles joined the band no later than 1794 ( Highfill , op. cit. ).

The later correspondence of George III , ed. by Aspinall A. , i (Cambridge, 1962; hereafter; George III ), Letter 656.

Chronicle , 125, 133–5. Further details of their property is to be found in Datchet past , by Janet Kennish (Chichester, 1999).

Chronicle , 135.

The Visitors Book (on loan to the Herschel Museum, Bath) shows that the King visited Herschel even while he was in tumbledown accommodation at Datchet.

On this see Bennett , op. cit. (ref. 5).

Watson Herschel , 29 June 1782, RAS MS Herschel W.1/13.W.18.

Chronicle , 133.

Chronicle , XI, 20–21. Matters did not in fact proceed as quickly as Watson would have wished. As early as 25 August 1784 (RAS MS Herschel W.1/13.W.32), he was asking Herschel “Has the King set you about the magnum opus, the great speculum?”, but it was to be nearly a year before Herschel made the formal application. Only on 24 September 1785 was Watson able to send Herschel his congratulations on the grant that would enable him “to undertake that glorious telescope which will excel all other instruments of that sort to so great a degree” (RAS MS Herschel W.1/13.W.39).

RAS MS Herschel W.5/12.1,69.

Chronicle , 144.

Bennett , op. cit. (ref. 5), 93.

He became a knight of the Hanoverian Guelphic Order in 1816. The Order had been founded the previous year by the Prince Regent, following the establishment of Hanover as a fully-fledged kingdom in the aftermath of the defeat of Napoleon. Knighthoods were awarded for distinguished services to the United Kingdom or Hanover, and Herschel was of course a native-born Hanoverian working in England.

RAS MS Herschel W.1/13.W.40, Watson Herschel , 11 November 1785.

Chronicle , 147.

“Le roi d'Angleterre a donné 3000 guinées, ou 75 mille francs, à M. Schroeter, pour ses instrumens, qui seront censés appartenir à l'université de Gottingen”, Connaissance des temps pour l'an XIII (1805), 255–6. On Schröter's instruments see the account in Henry C. King , The history of the telescope (London, 1955), 135–6, although King is wrong is saying Schröter purchased a complete 4ft: He merely needed to replace a broken mirror (letter of 2 Feb. 1783, RAS MS Herschel W.1/13.S.12). Schröter and his assistant Harding M. , whom the King also funded, played a central role in the first discoveries of asteroids.

George III , Letter 379.

Chronicle , XI, 19b; Memoir , 309 (letter of Caroline to Lady Herschel , wife of John, 10 January 1840).

In her early months in Bath Caroline had shared responsibility for the running of the house with a Mrs Bulman. The Bulmans were long-term friends of Herschel's, and they shared accommodation in Bath as they had done in Leeds. But Caroline was responsible for the accounts from the first, and for this her brother had to teach her some elementary arithmetic. On this see The Herschel partnership , in press.

Memoir , 178.

George III , Letter 369; RAS MS Herschel W.1/5.2.

See Appendix 3 below for his letter to the King from about this date ( George III , Letter 570), requesting the annual allowance for expenses to begin.

George III , 456, fn.

RAS MS Herschel W.1/13.B.20.

Memoir , 209.

RAS MS Herschel W.1/13.W.50.

Memoir , 211.

See Roy Porter , Mind forg'd manacles: Madness and psychiatry in England from Restoration to Regency (London, 1987).

Personal communication, 13 November 1997.

George III , Letter 570.

The first repolishing of the successful mirror began in July 1790 (RAS MS Herschel W.5/12.1, 128), so this letter presumably dates from July or August of that year.

George III , Letter 432.

So for example Cassini de Thury writes to Herschel on 15 February 1785 to say that he plans to visit England next year to see Herschel's telescopes “et de faire connaissance avec vous en sera le principal objet” of his visit, RAS MS Herschel W.1/13.C.6. Lalande writes on 8 November 1786: “J'espère l'été prochain aller lui rendre mes hommages, et voir votre superbe telescope de 40 piedes”, L.4; on 26 April 1787 he writes: “M. Sniadecki, professeur d'astronomie à Cracovie, ne pouvant retourner dans sa patrie sans aller visiter le premier sanctuaire de cette science,…”, L.5; on 12 May 1787 he asks if the 40ft is now operational, and if so he will come to England to see it, L.6; and on 21 May 1788 he again hopes for news of its completion: “Je prie M. Darquier de me donner des nouvelles du telescope de quarante pieds que j'attends pour faire le voyage d'Angleterre”, L.8.

RAS MS Herschel W.2/1.1.

On this and what follows, see Michael Hoskin , “William Herschel's early investigations of nebulae: A reassessment”, Journal for the history of astronomy , x (1979), 165–76, reprinted in Hoskin , Stellar astronomy: Historical essays (Chalfont St Giles, 1982), 125–36.

Michael Hoskin , “The Leviathan of Parsonstown: Ambitions and achievements”, Journal for the history of astronomy , xxxi (2002), 57–70; idem, “Rosse, Robinson, and the resolution of the nebulae”, ibid. , xxi (1990), 331–14.

WH, “On nebulous stars, properly so called”, PT , lxxxi (1791), 71–88.

RAS MS Herschel W.2/1.1, 1.

Herschel made his first sketch of the configuration of the satellites on 18 April 1783 (RAS MS Herschel MS W.3/1.8), and did this again several times in the weeks that followed. He observed the satellites four times in the summer of 1784 and once in 1785, after which he neglected them until August 1787.

Letter of 8 November 1786, RAS MS Herschel W.1/13.L.4.

RAS MS Herschel W.3/1.8. For a careful account of Herschel's work on Saturn, see O'd A. F. Alexander , The planet Saturn: A history of observation, theory and discovery (London, 1962), chaps. 8 and 9.

“… by de La Lande's letter which contains his tables”, RAS MS Herschel W.3/1.8. The tables were contained in Connaissance des temps for 1791, published in 1789, 288–94.

RAS MS Herschel W.3/1.8.

Chronicle , 163–4.

RAS MS Herschel W.2/4, f. 2v.

Chronicle , 165; RAS MS Herschel W.1/1, 181.

WH, “Account of the discovery of a sixth and seventh satellite of the planet Saturn”, PT , lxxx (1790), 1–20, p. 1.

RAS MS Herschel W.3/1.8, f. 27v.

WH, “On the power of penetrating into space by telescopes”, PT , xc (1800), 49–85, p. 85.

WH, “Astronomical observations relating to the sidereal part of the heavens”, PT , civ (1814), 248–84, p. 275.

WH, “A series of observations of the satellites of the Georgian planet”, PT , cv (1815), 293–362, pp. 295–6.

The quotation in Chronicle , 313, of a letter from Patrick Wilson Herschel , 10 August 1807, suggests that Herschel's great friend and ally Lalande condemned the 40ft in print: “I don't know if as yet you have met with De La Lande's History of Astronomy for the year 1806…. There is a paragraph concerning you and the 40-feet Telescope, evidently calculated to impress the belief of the total failure of your noble Instrument…”, RAS MS Herschel W.1/13.W.166. This is a misunderstanding on the part of Wilson. In Connaissance des temps pour l'an XIV , that is, 1806, published in 1804, Lalande has his usual section on the history of astronomy, but this contains nothing that could be construed as criticism of the 40ft. There is however a summary on pp. 453–8 of two of Herschel's recent PT papers, including “On the power of penetrating into space” (xc (1800), 49–85). The summary states: “… il craint que le plus grand grossissement ne puisse guères surpasser celui qu'on obtient d'un télescope de vingt-cinq pieds…. Pour parcourir ou balayer le ciel avec ce télescope [the 40ft] quand il grossit mille fois, à cent heures par année, il faudrait six cents ans” (pp. 454–5). If this was criticism of the 40ft, Herschel was being convicted out of his own mouth.

RAS MS Herschel W.2/4.

In April 1827 Caroline wrote to her nephew John Herschel a long defence of the 40ft. Forgetting that she had in fact made a start on assembling the observations made with the great reflector, she writes: “But what I most regret is, that I never could find an opportunity of consulting your father about collecting the observations made with the 40-foot into a separate book from the journals, into which they were written down among other observations made with the other instruments in the same night”, Memoir , 210.

RAS MS Herschel W.2/2.8, ff. 2v–3r.

Caroline later lamented the time wasted on this mirror, to the extent of making the unlikely assertion that their brother Alexander “would more than once have destroyed it secretly if I had not persuaded him against it”, letter to John Herschel , April 1827, Memoir , 209.

Letter to Charles Blagden , 27 November 1786, RAS MS Herschel W.1/1, 151–3.

RAS MS Herschel W.5/12.1, 114.

26 December 1793; it lasted just half an hour before being replaced by manpower, RAS MS Herschel W.5/12.3, expt 3.

WH, “Astronomical observations relating to the construction of the heavens”, PT , ci (1811), 269–336, p. 279.

RAS MS Herschel W.2/1.12, f. 41v.

RAS MS Herschel W.2/1.12, f. 48v.

RAS MS Herschel W.2/2.8, ff. 2v–3r.

RAS MS Herschel W.2/1.12, f. 54r.

RAS MS Herschel W.2/4, f. 3r.

WH, “On the power of penetrating into space by telescopes”, PT , xc (1800), 49–85, pp. 75–76; “Astronomical observations relating to the sidereal part of the heavens”, PT , civ (1814), 248–84, p. 275; “Astronomical observations and experiments, selected for the purpose of ascertaining the relative distances of clusters of stars”, PT , cviii (1818), 429–70, p. 439.

RAS MS Herschel W.2/4, f. 3.

RAS MS Herschel W.2/4, f. 4v.

RAS MS Herschel W.2/4, f. 4v.

WH, “Astronomical observations and experiments tending to investigate the local arrangement of the celestial bodies in space”, PT , cvii (1817), 302–31, p. 329.

Memoir , 210.

WH, “On the ring of Saturn”, PT , lxxxii (1792), 1–22, pp. 11–12; op. cit. (ref. 80, 1800), 76–77.

The scientific papers of Sir William Herschel , ed. by Dreyer J. L. E. (2 vols, London, 1912; hereafter: Dreyer ), i, p. liii.

RAS MS Herschel W.2/4, f. 3.

RAS MS Herschel W.2/4, f. 4v.

Dreyer , i, p. liii.

WH, op. cit. (ref. 80, 1814), 275.

WH, op. cit. (ref. 80, 1818), 450.

RAS MS Herschel W.3/1.9, 149; cf. Dreyer , i, p. liii.

Letter to Patrick Wilson , 26 December 1804, RAS MS Herschel W.1/1, 255–6. Patrick Wilson (1743–1811) was formerly a professor of astronomy at Glasgow, and was Herschel's soulmate in matters of natural philosophy. They held regular discussion meetings which they termed “philosophical chapters”.

WH, “Observations on the singular figure of the planet Saturn”, PT , xcv (1805), 272–80, p. 278–9.

Dreyer, i, p. liii.

WH, op. cit. (ref. 80, 1814), 274 (error in day corrected by Dreyer); op. cit. (ref. 80, 1818), 470; Dreyer , ii, 658; RAS MS Herschel W.2/2.8, f. 2. Most of his observations about this time were of Messier nebulae. Herschel was presumably refreshing his memory before writing his 1811 and 1814 cosmological papers.

RAS MS Herschel W.2/2.8, ff. 2, 3.

WH, op. cit. (ref. 74), 322; Dreyer , ii, 656; RAS MS Herschel W.2/2.8, f. 3v.

RAS MS Herschel W.3/1.9, 163; W.2/2.8, f. 17r. Dreyer , i, p. liii.

RAS MS Herschel W.2/2.8, f. 16v.

RAS MS Herschel W.2/2.8, f. 20r. Dreyer , i, p. liii, transcribes the record and assigns it to 1815, but this is a slip.

Memoir , 210.

RAS MS Herschel W.2/2.5, f. 52v.

Caroline quotes her brother as saying, “It is impossible to make the machine act as required without a room three times as large as this”, letter to John Herschel , April 1827, Memoir , 209.

Memoir , 113.

RAS MS Herschel W.5/12.

Dreyer, i, p. liv, footnotes.

Dreyer i, p. liv, footnote. “After 3 hours I find the mirror looks promising, but there remains, on trial, a confusion which can only be accounted for from the weakness of the metal which cannot take the figure properly”, RAS MS Herschel W.5/12.3, expts 380–1. The mirror had previously been polished on 24 April 1797 (by two men, W.5/12.3, expt 373).

RAS MS Herschel W.5/12.3, expt 382.

Five men were at work on 17 May (RAS MS Herschel W.5/12.3, expt 504); six on 2 October (W.5/12.3, expt 529).

Memoir , 106. It is true that when the mirror was polished in March/April 1802 (RAS MS Herschel W.5/12.3, expts 598, 599) Herschel says this was the first time for three years. But he made a similar remark in 1810 and we know this to be in error, for he says “it is not much above 2 ½ years since it was polished” (RAS MS Herschel W.2/2.8, ff. 2v–3r), though it is certain it was polished the previous year, see below.

RAS MS Herschel W.5/12.3, expts 598, 599.

Memoir , 112.

Memoir , 114.

Memoir , 155.

John Herschel's extracts from his mother's accounts, entry for 25 May 1809, papers kindly made available by Anthony J. Turner. .

Memoir , 117.

Nos 192, 194.

Memoir , 121.

Chronicle , XXIV, 33, follows Dreyer i, p. liii in putting this in 1815.

Memoir , 124.

Memoir , 123.

Memoir , 127–8.

The only persons we know to have been allowed to look through the 40ft are: Herschel's wife Mary, his brother Alexander, and “another lady”, who viewed Saturn on 24 September 1789 (RAS MS Herschel W.2/4, f. 3r); Professor Samuel Vince of Cambridge, M2, 4 September 1799 (WH, op. cit. (ref. 80, 1814), 275); and a Mr Greathead and his brother, Saturn on 5 November 1799 ( Dreyer , i, p. liii fn). There is no evidence that Caroline ever plucked up courage to venture aloft.

Chronicle , XXV, 8.

Memoir , 128.

Memoir , 210–11.

Dreyer, i, p. lv.

Dreyer, i, p. lv.

Memoir , 209–10.

RAS MS Herschel W.1/13.A.9, dated 31 August 1782.

“… que lui seul est en possession de voir dans le monde entier”, RAS MS Herschel W.1/13.B.99, letter from Charles Blagden forwarding a message from Laplace, 17 May 1814.

Chronicle , XI, 28, from Journal of Mrs. Papendiek , whose father held the lease of the house at Slough before it was taken over by William .

From Herschel's 1785 letter to Joseph Banks Sir (for the King) requesting funding for the 40ft, see Appendix 1.

George , Letter 236.

In George the letter is no. 369, but the associated Estimate of Expences is mistakenly printed on p. 363.

George , Letter 570.