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date: 21 July 2024

Baily, Francisfree


Baily, Francisfree

  • William J. Ashworth

Francis Baily (1774–1844)

by Thomas Goff Lupton (after Thomas Phillips, 1837)

Baily, Francis (1774–1844), stockbroker and astronomer, was born at Newbury, Berkshire, on 28 April 1774, the third son of Richard Baily (1744–1814), a banker, and his wife, Sarah Head (1745–1823). At the age of fourteen, following his education at the old grammar school in Newbury, he embarked upon an apprenticeship in a mercantile house based in the City of London. When he was seventeen he became 'intimately acquainted' with the natural philosopher and radical dissenter Joseph Priestley, of whom 'he always continued a warm admirer' (Herschel, 3). Baily both appreciated Priestley's natural philosophy and sympathized with his political views. In 1796 he embarked on a journey to North America with the official aim of forming or extending the commercial interests of a mercantile house in England. However, he was also fuelled by his republican tendencies, and while en route he announced his intention to take up United States citizenship.

Baily kept a detailed account of his tour, which was published a few years after his death as Journal of a Tour in Unsettled Parts of North America in 1796 and 1797 (1856). He admired the North American ideals of individualism, commercial spirit, liberty, and equal rights (Baily, 93–4). The journal also reveals his views on education and strong repulsion to slavery. He claimed, 'had they [negroes] the same advantages of education, they would equal white people in the improvement of their mental faculties' (Baily, 93). On returning to England in March 1798 he almost immediately began to make plans for another exploratory trip, and volunteered to travel in the service of the African Association, having formed a route of exploration to the Niger. However, the association was unable to raise the necessary funds, and soon afterwards Baily became a partner with one of his father's friends—'the eminent Mr. Whitmore of the Stock Exchange'.

Annuity practice

During his long career on the stock exchange Baily became a powerful figure in defining financial practices—in particular those appropriate for annuities and assurance societies. In 1802 he published Tables for the Purchasing and Renewing of Leases (a second edition appeared in 1807 and a third in 1812), in which he attempted to standardize the calculating base for the rules deducing the true value of a property lease via demonstrable principles. His objective was to obtain the true sum for the purpose or renewal of a lease of such estate accordingly. This depended on finding the clear annual rent of the property via a set of rules and tables he gave for its calculation.

Baily's early works on annuity tables and assurance societies reveal that he drew strongly upon the eighteenth-century radical dissenter Richard Price. His work on life annuities and insurances attempted systematically to algebraize the subject and represent various cases of annuities and assurances by symbols. He was also one of the first not to rely on Price's Northampton mortality tables, since, he claimed, the duration of human life was in fact longer than these tables suggested. In 1808 he published his highly successful and authoritative Doctrine of Interest and Annuities Analytically Investigated and Explained. This was followed in 1810 by his sequel, Doctrine of Life-Annuities and Assurances Analytically Investigated and Practically Explained. The latter also contained a critical guide to the several life-assurance companies in London, which later that year was published separately as a very popular pamphlet.

Baily's overriding concern was to establish a system to facilitate the buying and selling of annuities and leases with the object of alleviating the state of the national debt. The prevailing funding system had begun well managed—the money required for the service of government was borrowed for only a short duration (five to seven years). However, as the exigencies of the state increased, the term of the loan was lengthened to a period of 99 years and finally to the prevailing system of borrowing money on perpetuities. For Baily each change was more disastrous than the former. Baily's solution to the national debt, drawing heavily on Price, was simply to exchange the perpetuities for terminable annuities. The difference would then be paid through the sinking fund—'the very purpose for which that fund was established'.

In 1806 Baily talked at length in his The Rights of the Stock Brokers Defended Against the Attacks of the City of London of the dangers of seemingly plausible projects devised to make money on the stock exchange during the eighteenth century. For Baily, speculative projects and theories had to be effectively expelled from the financial and intellectual market. This meant a careful policing of information. The question centred upon what information was acceptable and what was not. This is highlighted in his vigilance on the stock exchange, which culminated in his central role exposing the fraud of De Beranger in 1814. De Beranger had been employed to supply intelligence from the scene of the war abroad with the purpose of influencing the price of British funds. Baily epitomized sound, thorough, precise thinking: 'everything to which he turned his thoughts', wrote John Herschel, was 'reduced to number, weight, and measure' (Herschel, 8). Baily presented himself and indeed was represented by others as the perfect citizen, reliable and uncorrupted by interests.

Historical writing

In 1812 Baily tried his hand at history and published A New Chart of History, accompanied by a Description—of which five editions were sold in three years. The work attempted to exhibit the chief revolutions of empire during the history of mankind. This was followed in 1813 by his popular two-volume work An epitome of universal history, ancient and modern; from the earliest authentic records to the commencement of the present year. Baily's approach was directly inspired by Priestley's Chart of History. He argued fiercely that, unless history was pursued systematically without the seemingly judgemental hand of human interests, 'the whole mass of historical records become confused; the transactions of various countries are divested of their two most essential qualities, time and place' (Baily, An Epitome of Universal History, 1813, 1.i–ii). History, like the position of the planets or information on the stock exchange, should be protected from deliberate or accidental distortion.

During the 1830s Baily applied his historical skills in an attempt to rejuvenate the reputation of John Flamsteed, the first astronomer royal, after his neighbour Edward Giles lent him a large collection of hitherto unknown correspondence between Flamsteed and Abraham Sharp, his assistant at the Royal Greenwich Observatory. Baily concluded that the letters implied that Flamsteed's adverse reputation was totally unjustified, and that he had been made the dupe of Isaac Newton and Edmond Halley. His sensational findings, An account of the Rev. John Flamsteed, the first astronomer royal; compiled from his own manuscripts and other authentic documents, never before published, were printed in 1835 at the public expense. For Baily the Flamsteed and Newton controversy provided a means to raise the profile and importance of methodical and practical work in the scientific labour process.

The Astronomical Society

Baily was also concerned that British science was falling behind developments on the continent. The state-sponsored Nautical Almanac, prepared by the board of longitude superintended by Thomas Young, represented a good target for him to promote his case. In a devastating onslaught he condemned the board's almanac for not keeping pace with improvements in astronomy. His first offensive against the board was launched in 1819, and it was here that he deliberately first suggested the utility of forming an astronomical society, which he co-founded with several others, including Charles Babbage and Herschel in 1820. Baily's attack continued with greater fervour after the society was set up, and in 1822 he privately printed Astronomical Tables and Remarks for the Year 1822. The main thrust of his argument revolved around the necessity of a set of tables suitable for both the observatory astronomer and the navigator, coupled with itemizing the numerous mistakes he apparently detected in many of the Nautical Almanac's calculations. By the close of the 1820s the credibility of the board of longitude had been successfully challenged, culminating in its closure, and the Admiralty had no choice but to turn to the Astronomical Society for advice on a new set of astronomical tables.

Baily laboured extremely hard to systematize mathematical tables in both assurance and astronomy. During the early 1820s he was very concerned with the need to remedy the prevailing confusion regarding the corrections for aberration, nutation, and refraction. In 1822, in collaboration with the actuary, mathematician, and stockbroker Benjamin Gompertz, he devised a means of simplifying their application. However, on learning that the Prussian astronomer Friedrich Bessel had devised and printed a similar scheme, he proceeded to publish and recommend Bessel's method instead. He accomplished this in the Astronomical Society's catalogue of 2881 stars (epoch 1 January 1830), which was accompanied by tables for reduction constructed on the new system. It was printed as an appendix to the second volume of the society's Memoirs in 1827, and Baily received the Astronomical Society's gold medal as a reward for his labours.

Baily relentlessly applied his tabular and calculating skills in revising former important star catalogues. His aim was to bridge the gap between the observations of past astronomers with those of the present: as Herschel put it, 'to ascertain all that has really been recorded of the stars, and to make that totality of knowledge the common property of astronomers' (Herschel, 41). Baily re-edited and published at his own expense the catalogues of Ptolemy, Ulugh Beigh, Tycho Brahe, Halley, Hevelius, Flamsteed, Lacaille, and Mayer in volume 13 of the Memoirs of the Royal Astronomical Society in 1843. He also produced most of the catalogue of the British Association for the Advancement of Science, which contained 8377 stars (reduced to 1 January 1850) of the sixth and higher magnitudes. The value of this catalogue, along with those he did for Lalande and Lacaille (the latter being reduced by Thomas Henderson), was greatly increased by the fact that he used a uniform system of reduction and nomenclature. Through Baily's labours the boundaries of the constellations were also revised and the stars composing them were arranged into a recognizable order. A paper on this subject was read to the Royal Astronomical Society on 12 May 1843 and was subsequently appended to the report of a committee (consisting of Herschel, William Whewell, and Baily) appointed by the British Association in 1840 to consider the subject.

Pendulum experiments

In response to a proposed expedition by Captain Foster, Baily devised in 1828 a simplified kind of convertible pendulum of which two specimens, of iron and copper respectively, formed part of the scientific equipment of the Chanticleer. The accidental death of the ship's commander in February 1831 threw Baily into the role of completing the numerous observations in both hemispheres by swinging the pendulums in London. He produced a report for the Admiralty which was later published by the government. His results took up the entire seventh volume of the Royal Astronomical Society's Memoirs. The general result of 20,000 experiments gave 1289.48 for the ellipticity of the earth, showing a satisfactory agreement with Edward Sabine's result of 1288.40.

Baily had also independently set to work on determining the length of the seconds pendulum. Bessel had pointed out in 1828 that to date the resistance of the air had not been included as a factor of resistance in the measurement. Consequently, Baily had a vacuum apparatus erected in his house, and there carried out between 1831 and 1832 a series of experiments on eighty-six pendulums of every variety of form and material, of which the details were communicated to the Royal Society in May 1832. It appeared thence that the value of the new correction, while varying very sensibly with the shape and size of the pendulum, was in many cases more than double the old.

The subject of the length of the seconds pendulum led naturally to that of the national unit of length defined by statute ( 5 George IV), which now proved to be of an uncertain quantity. As a result, Baily obtained in 1833 from the Royal Astronomical Society authority to construct for them a tubular scale of 5 feet, the accuracy of which had been ascertained by repeated comparisons with the standard yard. The issue became particularly urgent with the burning of the houses of parliament in October 1834, and with it the destruction of the national standard. Thus a commission of seven, including Baily, was appointed in May 1838 to consider the best means of replacing it. It was decided in 1843 that Baily should be entrusted with the actual reconstruction of the standards of length. However, he died the following year before he was able to complete the task.

In 1835 a committee was appointed at the Royal Astronomical Society to repeat Henry Cavendish's experiment to measure the earth's density. However, nothing actually happened until, in 1837, Baily offered his services and was awarded a grant of £500 towards expenses. Between October 1838 and May 1842 he devoted his time to this task in the upper room of his house. He concluded that the earth was composed of materials on average 5.66 times as heavy as water, but an unknown error was detected in his results. The Scottish experimental philosopher James Forbes suggested that the anomalies in question might be due to the radiation of heat from the leaden masses employed to deflect the pendulum, and proposed gilding both them and the torsion box. The remedy was successful and Baily began the process afresh in January 1841. The printed observations published in the fourteenth volume of the Memoirs of the Royal Astronomical Society numbered 2153 (including a thousand observations deemed untrustworthy). The society awarded Baily his second gold medal in 1843 for his labours.

Baily also spent a great deal of time diffusing astronomical developments and methods of calculation into the sphere of the general public, with numerous of his articles appearing in the Philosophical Magazine. He is celebrated for his detection of a phenomenon known as ‘Baily's beads’. While observing an annular eclipse in May 1836, he noted the breaking up of the fine solar crescent visible at the beginning and end of central eclipses into a row of lucid points, or beads, the intervals separating which at times appear to be drawn out, as the moon advances, into dark lines or belts—the whole being the combined effect of irradiation and the inequalities of the moon's edge.

As well as his work in founding and administering the Astronomical Society, Baily served on numerous scientific committees and held an array of positions in scientific societies. For example, from 1839 he was permanent trustee of the British Association, and on various occasions he was vice-president and treasurer of the Royal Society. He helped establish the Royal Geographical Society in 1830 and became its vice-president [see Founders of the Royal Geographical Society of London]. He was also a fellow of the Linnean Society and the Society of Civil Engineers, was a corresponding member of the Institute of France and the academies of Berlin, Naples, and Palermo, and was enrolled on the lists of the American and Royal Irish academies.

Baily never married and lived for much of his life with his sister Elizabeth Baily, at 37 Tavistock Place, London. In June 1841 he was knocked senseless by a speeding rider while crossing Wellington Street, and was unconscious for a week. He died at home of kidney disease shortly after receiving an honorary degree from Oxford University, at the age of seventy, on 30 August 1844, and was buried at Thatcham church, Berkshire.


  • F. Baily, Journal of a tour in unsettled parts of North America in 1796 and 1797 (1856) [incl. memoir by J. Herschel]
  • J. Herschel, ‘Memoir of Francis Baily’, Memoirs of the Royal Astronomical Society, 15 (1846)
  • L. G. H. Horton-Smith, The Baily family of Thatcham and later of Spleen and of Newbury (1951)
  • W. J. Ashworth, ‘The calculating eye: Baily, Herschel, Babbage and the business of astronomy’, British Journal for the History of Science, 27 (1994), 409–41
  • W. J. Ashworth, ‘“Labour harder than thrashing”: John Flamsteed, property and intellectual labour in nineteenth-century England’, Flamsteed's stars: new perspectives on the life and work of the first astronomer royal, ed. F. Willmoth (1997), 199–216


  • Bodl. Oxf., corresp.
  • CUL, papers
  • Institute of Actuaries, MSS
  • LUL, tables, etc., and letters received
  • RAS, corresp. and papers
  • BL, letters to Charles Babbage, Add. MSS 37182–37189
  • CUL, letters to Sir George Airy
  • RAS, letters to Royal Astronomical Society
  • RS, letters to Sir John Herschel
  • RS, letters to Sir John Lubbock
  • RS, letters to S. P. Rigauld
  • RS, letters to Sir Edward Sabine
  • U. St Andr. L., corresp. with James Forbes


  • T. Phillips, oils, 1838, RAS
  • T. Phillips, oils, exh. RA 1839, RAS
  • E. H. Baily, marble bust, 1848, RAS
  • E. H. Baily, marble bust, 1848, NMM
  • T. G. Lupton, engraving (after portrait by T. Phillips, 1837), NPG [see illus.]
  • F. J. Skill, J. Gilbert, W. and E. Walker, group portrait, pencil and wash (Men of science living in 1807–08), NPG

Wealth at Death

over £21,000: Horton-Smith, The Baily family

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