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Papers of the Board of Longitude : Correspondence regarding methods of establishing longitude by Jupiter's satellites, the planets and fixed stars

Papers of the Board of Longitude

<p style='text-align: justify;'>This volume contains forty-five sections of correspondence dating from 1783 to 1828. Most of the letters and proposals in this volume concern astronomical methods of finding the longitude at sea other than the lunar and related publications and technology. The methods proposed here focus on finding longitude by either Jupiter's satellites, the sun or sometimes by the fixed stars and Moon. The papers in this volume continue in <a href='/view/MS-RGO-00014-00037'> (RGO 14/37)</a>. This volume is weighted, as are all of the RGO volumes, towards the later history and activities of the Board of Longitude.</p><p style='text-align: justify;'>This volume belongs to a series of RGO volumes into which the later Astronomer Royal George Airy [<a target='_blank' class='externalLink' href=''><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>] sorted Board of Longitude correspondence regarding different types of schemes in 1858. The contents of volumes <a href='/view/MS-RGO-00014-00032'> (RGO 14/32)</a> and <a href='/view/MS-RGO-00014-00033'> (RGO 14/33)</a> discuss the lunar-distance method [<a target='_blank' class='externalLink' href=''><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>], <a href='/view/MS-RGO-00014-00034'> (RGO 14/34)</a> and <a href='/view/MS-RGO-00014-00035'> (RGO 14/35)</a> regard other lunar methods, RGO 14/36 and <a href='/view/MS-RGO-00014-00037'> (RGO 14/37)</a> encompass astronomical methods employing Jupiter's moons and the planets and fixed stars, <a href='/view/MS-RGO-00014-00038'> (RGO 14/38)</a> deals with other methods and instruments including the use of chronometers, and <a href='/view/MS-RGO-00014-00039'> (RGO 14/39)</a> and <a href='/view/MS-RGO-00014-00040'> (RGO 14/40)</a> contain so-called 'impracticable' schemes.</p><p style='text-align: justify;'>Throughout its existence as an officially meeting and then standing institution, the Board of Longitude mainly pursued lunar distances amongst the astronomical schemes for finding longitude at sea. However, the Board also periodically considered alternative methods. A number of the letters in this volume record the judgments passed upon these schemes by Nevil Maskelyne [<a target='_blank' class='externalLink' href=''><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>] and by other experts and practitioners. They also record the dates that the Commissioners heard the correspondence and sometimes took relevant actions. This is elaborated upon in other sources including the official Board minutes.</p><p style='text-align: justify;'>Many of the projectors in this volume came from the sectors one would expect, such as the astronomer (and later critic of the Board) James South (see <a target='_blank' class='externalLink' href=''>portrait</a> at the National Portrait Gallery), and the mathematicians George Douglas and James Leslie of Edinburgh). William Chevasse and Charles Becher worked for the East India Company [<a target='_blank' class='externalLink' href=''><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>], while James Ewart may have been either the M.D. of that name with the Calcutta branch of the Standard Life Assurance Company or a Lieutenant in the Bengal Artillery. <a href='' onclick='store.loadPage();return false;'> Ewart (RGO 14/36:24)</a> made observations of Jupiter's satellites with the aid of a chronometer from John Arnold (see <a target='_blank' class='externalLink' href=''>portrait</a> at the British Museum), which he sent to the London clockmaker as promised. It appears this was more for terrestrial surveying than for finding the longitude at sea. There was also at least one schoolmaster amongst the projectors, William Innes.</p><p style='text-align: justify;'>However, there was also a linen draper, John Lowe of Manchester, and a number of religious men including the Reverend <a href='' onclick='store.loadPage();return false;'>RGO 14/36:4</a>, a Minister of the Gospel at Tengwall in Zetland (Shetland) in Scotland. Mitchel tried to interest the Commissioners in his quadrant for observing the satellites of Jupiter and other instruments. His efforts are described in the Board minutes and in volume <a href='/view/MS-RGO-00014-00012/'> (RGO 14/12:364)</a> as well. In 1808James Playfair, Minister of Bendothy near Coupar Angus in Scotland, <a href='' onclick='store.loadPage();return false;'> contacted (RGO 14/36:40)</a> the Board about a sea telescope for the same purpose. The projectors as a whole mostly hailed from Britain, except for the mercantile Captain Matthew Groves of Massachusetts in America.</p><p style='text-align: justify;'>The contents of this volume, like others in the RGO 14 archives, reflect the extent to which the activities of the Board of Longitude intertwined with those of other bodies, especially the Admiralty and sometimes others such as the East India Company. They also show how the Board's operation and activities involved as many or more interpersonal interactions and individual decisions as they did official meetings and communal decision-making. Some of this correspondence was sent to individual actors rather than to the relevant institutions. For example, in 1814 George Douglas<a href='' onclick='store.loadPage();return false;'> wrote (RGO 14/36:160)</a> to the MP William Vansittart because he thought that Vansittart he had a great interest in the sciences and in the State - although the politician simply <a href='' onclick='store.loadPage();return false;'> forwarded (RGO 14/36:161)</a> the letter to the Commissioner Viscount Melville, to be sent on to the Secretary Captain Thomas Hurd [<a target='_blank' class='externalLink' href='!csearch;authority=agent-178430;makerReference=agent-178430'><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>].</p><p style='text-align: justify;'>Many letters further exhibit how common it was for longitude projectors to seek the Board's financial aid because of a litany of troubles, only some of which related to their pursuit of the longitude at sea. In 1803, Captain Matthew Groves of Massachusetts first <a href='' onclick='store.loadPage();return false;'> wrote (RGO 14/36:33)</a> to Joseph Banks rather than to the Board or Admiralty about his method and patented astronomical quadrant for finding longitude via Jupiter's moons. Groves had contacted the American President Thomas Jefferson (see <a target='_blank' class='externalLink' href=''>portrait</a> at the British Museum)about his invention and <a href='' onclick='store.loadPage();return false;'> claimed (RGO 14/36:35)</a> to have obtained his approval for it. He also <a href='' onclick='store.loadPage(70);return false;'> asked the Board for financial assistance for his trials (RGO 14/36:35v)</a>, since the money he had raised in Boston by subscription had since run out.</p><p style='text-align: justify;'>Amongst the many other schemes in this volume involving new technologies are three for so-called 'marine chairs' or marine observatories. These were intended for steadier telescopic observing of Jupiter's satellites and other celestial bodies while aboard ship. Such chairs had been proposed to the Board of Longitude from at least the 1750s on. They tended to involve actual chairs or platforms for astronomical viewers which were steadied by vast gimbals or pendulums either aboard ship, like the early chair of the Irishman Christopher Irwin, or floating almost freely in the water like that of Lieutenant William Chevasse. Irwin's progress and encouragements from the Board can be traced through the official minutes in volume <a href='/view/MS-RGO-00014-00005'> RGO 14/5 (RGO 14/5)</a> and in sources such as early modern newspapers and periodicals.</p><p style='text-align: justify;'>In 1813, Chevasse presented the Board with a description and lovely <a href='' onclick='store.loadPage();return false;'> watercolour (RGO 14/36:51)</a> of his proposed chair. Five years later, a correspondent passed on a description and diagram of another chair invented the year before by the Scottish minister and inventor <a href='' onclick='store.loadPage();return false;'>RGO 14/36:77</a>, who had previously invented a 'euharmonic organ'. Finally, in 1820 the Naval midshipman Peter Lecount<a href='' onclick='store.loadPage();return false;'> asked (RGO 14/36:91)</a> for money to build his proposed chair in the Naval Dockyard because he had spent most of his own on conducting magnetic variation experiments. After making it, Lecount <a href='' onclick='store.loadPage();return false;'> reported (RGO 14/36:93)</a> in 1821 that he had tested it in the Channel with purportedly good results. However, he next <a href='' onclick='store.loadPage();return false;'> wrote (RGO 14/36:94)</a> that he had to stop the trials because of poor weather and his poor eyesight and health. His <a href='' onclick='store.loadPage();return false;'> final letter (RGO 14/36:95)</a> of 8 January 1823 reported that the chair was not yet steady enough, but that Lecount would keep working on it.</p><p style='text-align: justify;'>The content of this volume also reflects a number of other interesting points. Poor weather or war sometimes delayed post to and from the Board. William Mitchel's <a href='' onclick='store.loadPage(24);return false;'> postscript (RGO 14/36:12v)</a> to a letter of 1787 mentions that it had taken more than three months for the Secretary's last letter to reach Zetland. This was due to the Shetland packet having been laid up at Leith during the winter months. Captain John Boyle (then of Walworth) <a href='' onclick='store.loadPage();return false;'> said (RGO 14/36:193)</a> in 1798 that he had waited almost two whole months to send a letter because of the threat of a French invasion. James Leslie expressed a relatively common complaint amongst projectors when he <a href='' onclick='store.loadPage();return false;'> requested (RGO 14/36:112)</a> the return of the papers that he had sent to the Board.</p><p style='text-align: justify;'>Additionally, the case of William Fuller of London touches upon projectors' frequent use of the newspapers to advertise their schemes and to try to reach out to the Commissioners or to other potential patrons. Fuller sent the Board a <a href='' onclick='store.loadPage();return false;'> handbill (RGO 14/36:127)</a> in 1783, which described how he had published his method of finding the longitude by the fixed stars in the newspapers. He had also taken copies to the Houses of Parliament, the Admiralty, and different Coffeehouses. He expected the Commissioners to then contact him about his new transit instrument and tables of the fixed stars, but the Secretary Henry Parker<a href='' onclick='store.loadPage();return false;'> responded (RGO 14/36:129)</a> that the Board did not pay attention to 'advertisements' and that he would need to apply in a different manner. Maskelyne met with Fuller about his ideas and then <a href='' onclick='store.loadPage(254);return false;'> wrote (RGO 14/36:130v)</a> on the back of his letter that he was 'of opinion that they do not merit the attention of the Board of Longitude'. As Thomas Hurd <a href='' onclick='store.loadPage();return false;'> told (RGO 14/36:71)</a> a supporter of John Hawkes in 1817: 'The opinions & duties of a Public Board are not always in unison with the sanguine expectations of Inventors'.</p><p style='text-align: justify;'>Alexi Baker<br />History and Philosophy of Science<br />University of Cambridge<br /></p>

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