The First Time Balls

The chronometer method for determining longitude became practical with the successful sea trials of John Harrison's H4 chronometer on two sea voyages in 1761–62 and 1764. By comparing local time determined by celestial observations (see ref. 3) with port time maintained by the chronometer, the difference in longitude between the port and the ship could be calculated. Maskelyne's publication in 1766 of The nautical almanac and astronomical ephemeris for the year 1767 made possible the rival method of lunar distances, which determined time by observing the position of the Moon relative to certain nearby stars. The chronometer method was simpler, but often both methods were used as a check on each other. A case in point is Sir John Herschel's voyage to the Cape of Good Hope, described in his diary entry for Friday, 20 December 1833: “The Captⁿ in a great puzzle about his Lunars. All hands at work taking obs^ns and at last as a final result the Lunars of yesterday and today give −27^s for the Chronometer error while all Chronom^rs make it +2^m 21^s. Bad work this. But a Lunar at Sea seems rather a bungling business.” The next day Herschel reported that “by plenty of patience and using masses of obs^ns “they came to a satisfactory conclusion, with the lunars and chronometers tallying within one-half minute of time or about 8 miles of longitude. Evans David S. (eds), Herschel at the Cape: Diaries and correspondence of Sir John Herschel, 1834–38 (Austin and London, 1969), 16–17.

The calculation was made as follows: If on 27 May at 9^h a.m. the chronometer was slow 2^h7^m18^s and on 3 June at 5^h p.m. the chronometer was slow 2^h6^m51^s then the difference in the error in 7^d8^h was 0 0 27^s or, a daily rate of 3·7 seconds, gaining. The navigator would use this new rate for determining his longitude until another rate could be obtained. See Raper Henry , The practice of navigation and nautical astronomy (9th edn, London, 1866), 275. Note that the observation had to be made at the same meridian, or the rate could not be disentangled from a change in longitude of the ship.

The method most often used was to observe the ‘equal altitudes’ of the Sun or stars; that is, the times when the object had equal altitudes before and after passing the meridian. The arithmetical mean gave the time the star passed the meridian. When the Sun was observed, its daily motion in declination had to be taken into account. The method could be used at sea, but was not as accurate with the sea horizon, and so was carried out on land when possible. A ‘single altitude’ method could also be used, but was not as accurate. Raper , op. cit., 276.

Howse Derek , Greenwich Observatory: Origins and early history, 1635–1835 (London, 1975), 150; Gould R. T. , The marine chronometer: Its history and development (London, 1923), 253.

Dick Steven J. , “How the U.S. Naval Observatory began, 1830–1865”, Sky and telescope, lx (1980), 466–71.

For the care and handling of chronometers at sea and ashore see Shadwell C. F. , Notes on the management of chronometers and the measurement of meridian distances (new edn, London, 1861).

U.S. National Archives, Record Group 45, Naval Records Collection of the Office of Naval Records and Library; Entry 222, Records of the Board of Navy Commissioners, Letters Received from the Secretary of the Navy, v (1829–30), 207, 211–19. This set consists of four letters and the printed “Plan”.

Robert Wauchope entered the Royal Naval Academy at Portsmouth in December 1802, and served on various ships, 1805–19 and 1834–38. He was promoted to the rank of commander in 1812, and to captain in 1814, after which he commanded the Swinger, the Eurydice, and the Thalia. Wauchope and his wife were intimate friends of John Herschel and his family during Herschel's years at the Cape, serving as godparents to Herschel's second son Alexander. Wauchope occasionally accompanied Herschel at the 20ft reflecting telescope, and returned some of Herschel's observations to England aboard the Thalia. Some 42 entries on Wauchope and his family are contained in Herschel's diaries and correspondence at the Cape. Evans (eds), op. cit. (ref. 1). Wauchope was an Admiral at his death in Edinburgh, 14 June 1862. He is listed in O'Byrne's Naval biographical dictionary (London, 1849), 1261.

Wauchope R. , “Plan for ascertaining the rates of chronometers by signal”, Edinburgh new philosophical journal, viii (1830), 160–2; and “Description of the apparatus or signal-post for regulating chronometers”, ibid., 289–91.

Writing in 1836 to claim priority for the invention, Wauchope refers to an 1818 discussion of its advantages in his “remark-book transmitted to the Admiralty when in command of the Eurydice, at that time on the Cape and St. Helena station” (“Time signals for chronometers”, Nautical magazine, v (1836), 460–4). This letter to the editor, dated 2 April 1836, is accompanied by much of Wauchope's correspondence on the subject of his invention, and by the comments of the editors. The date of 1824 for the first time ball suggestion was given in “The time-ball of St. Helena”, Nautical magazine, iv (1835), 658–60, which appears to have been written by the magazine's editors. It was upon reading this article that Wauchope wrote to the editors with his 1818 priority claim. Derek Howse also gives the 1824 date in Greenwich time and the discovery of the longitude (Oxford, 1980), 79.

Tuck O. , “The old telegraph”, The fighting forces, i (1924), 465–81. There were 47 stations between North Foreland and Land's End. The signals given were formed by “hoisting various numbers of black balls to a yardarm …”.

See the editors' comments, “Time signals for chronometers” (ref. 10) 463.

Apparently first at Greenwich. See Laurie P. S. , “The Greenwich time ball”, The observatory, lxxvii (1958), 113–15.

We obtain this date from Wauchope's correspondence with Professor Robert Jameson, the editor of the Edinburgh new philosophical journal, and with the various Secretaries to the Admiralty, whose answers were invariably signed by John Barrow, for 41 years the Second Secretary. In his cover letter to Jameson dated 23 November ( Wauchope , op. cit. (ref. 9), 160), Wauchope quotes from a letter of 12 November 1829 sent to him by an officer stationed at Portsmouth, in which the officer described a ship's chronometer rating by the usual method of observing with a sextant and artificial horizon, the chronometer having been brought ashore: “The Admiral and myself were at the King's Stairs…. I then repeated to the Admiral … your plan, marking this [unsatisfactory chronometer rating] process as a case in point. From that moment he pursued its adoption with energy, and it is now, although in an infant operation, quite sufficiently established to give proof of complete success. “In a letter dated 22 June 1830 (printed in “Time signals for chronometers” (ref. 10), 462), Wauchope queried the Admiralty regarding his plan “which is at present on trial at Portsmouth”. Barrow's reply (National Archives, op. cit. (ref. 7), 217, also printed in “Time signals for chronometers” (ref. 10), 462) shows that its testing had been completed before 6 July.

Wauchope even suggested that the clock could be fitted to drop the time ball automatically. Wauchope , op. cit. (ref. 9), 160–1.

This observatory was at the Royal Naval College (until 1808 the Royal Naval Academy) in the Portsmouth Dockyard. The observatory may have had its origins in the sea trials of Harrison's H4 chronometer, since the ships for both the 1761–62 and 1764 trials departed from Portsmouth. On the first trial the local time at Portsmouth was determined by equal altitudes of the Sun observed from “the Royal Academy at Portsmouth Dockyard”. On the second trial the equal altitude observations were taken “at the observatory in Portsmouth” and Harrison's timepiece “compared with the clock in the observatory”. Maskelyne Nevil , An account of the going of Mr. John Harrison's watch, at the Royal Observatory, from May 6, 1766, to March 4, 1767 (London, 1767), l–li. The statement is found in the “Appendix containing observations of equal altitudes of the Sun taken at Portsmouth, Jamaica, and Barbadoes …”. Gould , op. cit. (ref. 4), 59, notes that before departure on the second trial, Harrison's son “checked the timekeeper's rate by comparison with a regulator installed in a temporary observatory”, the clock “lent for this purpose by the Duke of Richmond”. According to a source contemporary with Wauchope's discussions, the observatory was later equipped with “an excellent astronomical clock, a good transit instrument, and a telescope at the public expense. A series of astronomical observations have been carried on at this observatory for many years by the late Mr. William Bayly, headmaster of the Royal Academy, who was one of the best calculators and accurate astronomers of the age, having been several years employed as an assistant to that able astronomer Dr. Maskelyne, at the Royal Observatory at Greenwich, where he calculated several of the early volumes of the Nautical Almanac …”. Burney William , A new and universal dictionary of the marine (London, 1830), a modernized and much enlarged version of Falconer's Marine dictionary by William Falconer. Bayly (1737–1810) was headmaster of the Royal Academy from 1785 to 1807.

Wauchope , op. cit. (ref. 9) 162.

“The time-ball of St. Helena” (ref. 10) 659.

A relay configuration was apparently used at St Helena in 1834, “The time-ball of St. Helena” (ref. 10), 660. Warner Brian , Astronomers at the Royal Observatory Cape of Good Hope (Cape Town, 1979), 64, describes the 1853 ball at Lion's Rump Signal Station whose drop time was controlled by telescopic observation of the observatory time ball.

Upton Winslow , “Information relative to the construction and maintenance of time-balls”, United States of America, War Department, Professional Papers of the Signal Service, no. 5 (October 1881), 12.

In May 1835 the commander of an East India Company ship writes of “the admirable plan recently adopted at Greenwich and Portsmouth, of dropping a ball at a given moment … the only ones where the ball is now dropped” ( Liddell James , “Communicating longitude at sea”, Nautical magazine, iv (1835), 401–3). In August 1836 the Nautical magazine editors (“Time signals for chronometers” (ref. 10), 463) write that the 1818 plan “is the same in principle as the system adopted at Portsmouth and Greenwich”, so we conclude the time ball is still operational then. We believe that the lack of a detailed discussion of the Portsmouth time ball in any one place in this journal-of-record is due to the date of the test—two years before the magazine's establishment.

Laurie , op. cit. (ref. 13), 115. A time ball remained in use at Portsmouth until about 1914.

Wauchope , op. cit. (ref. 9) 290.

National Archives, op. cit. (ref. 7), 217, also printed in “Time signals for chronometers” (ref. 10), 462. The letter is dated 6 July 1830.

“Time signals for chronometers” (ref. 10), 461. The cover letter to the American ambassador is dated 21 July 1830. Wauchope writes “the object … is to get the Plan generally adopted, so that Ships of all nations may have it in their power, immediately upon entering a port, to get an accurate Rate for their Chronometers, without which they are worse then useless. And that Merchant Ships may be induced by this facility given them, to adopt the use of Chronometers more generally to the great saving of both Life, & Property” (National Archives, op. cit. (ref. 7), 218).

National Archives, op. cit. (ref. 7), 207, 219.

Dick , op. cit. (ref. 5), 466–71.

The report by the Board of Navy Commissioners on the reorganization of the Navy, including the provision for better care of navigation equipment, was written in November 1829. For the events that followed see Dick , op. cit. (ref. 5) 467.

Thomson Malcolm M. , The beginning of the long dash: A history of timekeeping in Canada (Toronto, 1978), 4, writes that “prior to 1835, there was no fixed astronomical observatory on the North American continent …”. There were places—the observatory in Jamaica dismantled before the arrival of Harrison's chronometer H4 in January 1762, for example—where equipment was available to equip an observatory at the level needed for Wauchope's proposal. Dick , op. cit. (ref. 5) also describes the U.S. Congress's opposition to an astronomical observatory, which was possibly an additional factor.

Dick , op. cit. (ref. 5), 467, 468.

Wauchope , op. cit. (ref. 9), 160, 289; Wauchope , op. cit. (ref. 43 below), 160; and “Time signals for chronometers” (ref. 10) 461.

The Liverpool Observatory, which became the outstanding institution for marine chronometer testing, operated a time ball when it began in 1844. At the 1837 meeting of the British Association for the Advancement of Science held in Liverpool, the President of the Association proposed the establishment of an observatory there. A committee, which included the astronomer Francis Baily, was formed and in a memorial to the corporation stated “that the inaccuracies in the Greenwich mean time given in some of the principal ports in the kingdom were known to be sufficient to cause the wreck of ships” ( Baines Thomas , Liverpool in 1859: The Port & Town of Liverpool, and the harbour, docks, and commerce of the Mersey in 1859 (London, 1859), 53). Baines, a city father, also states that “the observatory was established in consequence of these and similar representations”. Although this is a weak thread by which to deduce Wauchope's influence, the time of Wauchope's writings—1830 to 1836—is appropriate, and we note other indications of a maritime, in contradistinction to a scientific or astronomical influence in this particular case. See “The time-ball at Greenwich” (ref. 47), 584; and Liddell James , “St. Helena time-ball”, Nautical magazine, vi (1837), 364–5. The Edinburgh time ball was erected on Calton Hill in 1855, but Smyth Piazzi Charles , the Astronomer Royal for Scotland, had advocated its erection since his arrival in 1846 ( Smyth , Edinburgh astronomical observations, vi (1846), Appendix, 17). Note that his listing of time balls here is incomplete. Smyth had been First Assistant at the Cape Observatory from 1835 to 1845, and according to Warner “had copied the Cape method of announcing midday with the aid of a time-gun and Time Ball” ( Warner , op. cit. (ref. 19), 80). This process of diffusion via the Cape, rather than directly, is discussed further in the text.

See Wauchope's letter in “Time signals for chronometers” (ref. 10), 460, and the confirmation of the naval commissioner, Brenton Jahleel , ibid., 463.

Meeting Sir Jahleel Brenton on his very first day. See Warner , op. cit. (ref. 19) 6.

According to Warner , ibid., 10. This signal is mentioned elsewhere, as in “The time-ball of St. Helena” (ref. 10), 658, but the year ascribed (1820) is obviously wrong.

Warner , op. cit. (ref. 19), 32. Gill David , A history and description of the Royal Observatory Cape of Good Hope (London, 1913), cxliii, describes a time ball operated “in the days of Fallows and Henderson”. Fallows's tenure at the Cape was from 12 August 1821 until his death 25 July 1831, so if Gill's statement is correct, it could change our view regarding the first time ball. Gill does not mention Fallows's lamp/shutter signal, and we know the time-pistol was unavailable to Fallows. We conclude that Gill's description is an anecdote that combines Fallows's 1823 lamp/shutter ( Warner , op. cit. (ref. 19), 10), Henderson's 1833 pistol (ibid., 47), and the 1853 time ball under Maclear's supervision at Lion's Rump Signal Station (ibid., 64). Warner (ibid., xi and 22) discusses similar anecdotes that he has been unable to document.

Warner , op. cit. (ref. 19) 47.

Ibid., 47. This is made even more probable by the friendship between Wauchope and Maclear evident in Herschel's diaries at the Cape ( Evans , (eds), op. cit. (ref. 1), 149, 213).

The observatory building was completed in 1828 and Johnson Manuel J. was appointed astronomer on 24 January 1828. See Gosse Philip , St. Helena, 1502–1938 (London, 1938), 331–4. Warner , op. cit. (ref. 19), 23, cites Johnson's earlier visits to Fallows at the Cape, and his interaction with Henderson in 1833 (ibid., 36).

The time-ball service is described in detail in “The time-ball of St. Helena” (ref. 10), 658–60, and noted by Liddell , op. cit. (ref. 21a), 403. The time-ball notice is cited in the St Helena article, 660.

“The time-ball of St. Helena” (ref. 10) 659.

See Gosse , op. cit. (ref. 38); Thomson , op. cit. (ref. 28), 3; and Liddell , op. cit. (ref. 31) 365.

We have no evidence that Wauchope influenced another pre-Greenwich time ball, one established at the Port Louis, Mauritius observatory on 25 April 1833, the government notice being given in “Rating chronometers at the Mauritius”, Nautical magazine, iv (1835), 136. The time ball was still operational in 1836 (“Chronometers at the Mauritius”, Nautical magazine, vi (1836), 365). The initial date for this time ball is given as 1832—still after the Portsmouth time ball—in another government document (Colony of Mauritius, Education Department, The historical monuments of Mauritius (Port Louis, 1958), 1).

Wauchope R. , “Establishment of Captain R. Wauchope's signal for ascertaining the rates of chronometers at the Royal Observatory, Greenwich”, Edinburgh new philosophical journal, xvi (1834), 157–60.

The letter is dated 17 June 1833, and is excerpted in “Time signals for chronometers” (ref. 10), 462. Note that Brenton Jahleel Sir , who figures in the 1818 history and the Cape Observatory time ball, is given credit for suggesting the importance of Greenwich.

Ibid., 463. Another copy of it is in Wauchope , op. cit. (ref. 43) 158.

See the editorial notices, “Chronometer rates”, Nautical magazine, ii (1833), 488 and 680.

The first detailed description is given in “The time-ball at Greenwich”, Nautical magazine, iv (1835), 584–6. For the general history of the Greenwich time ball see Laurie , op. cit. (ref. 13), 113–15; and Howse Derek , op. cit. (ref. 4), iii, 134–6, and op. cit. (ref. 10), 79–80.

There is a famous Punch cartoon showing the Astronomer Royal as a time ball on the Observatory ( Howse , op. cit. (ref. 10), 103).