skip to content

Papers of the Board of Longitude : Correspondence on finding latitude

Papers of the Board of Longitude

<p style='text-align: justify;'>As 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>]'s <a href='' onclick='store.loadPage();return false;'> title page (RGO 14/41:2)</a> from 1858 says, the letters in this volume centre upon 'Methods for Latitude &c'. Most mainly or solely discuss improved methods of and instruments for finding latitude at sea. This subject also appears scattered across other RGO volumes. For example, there is correspondence in <a href='/view/MS-RGO-00014-00029/433'> (RGO 14/29:214r)</a> from John Dykes of London and Edinburgh in 1815 and 1816. He describes a new instrument for finding latitude. However, some of the letters in this volume encompass or revolve around other subjects. These include finding terrestrial latitudes or longitude at sea, magnetic variation, and errors in chronometers. For example, James Kirkwood of London <a href='' onclick='store.loadPage();return false;'> proposed (RGO 14/41:20)</a> to 'regulate the time for finding the Longitude'. He also sought to find latitude by observations of celestial altitudes. He objected to public speeches in the wake of the <a href='/view/MS-RGO-00014-00001/157'> Longitude Act of (RGO 14/1:79r)</a>, which appeared to suggest that the longitude was already to be easily found to within a mile.</p><p style='text-align: justify;'>These letters come from the final decades of the existence of the Commissioners of Longitude, at least in part because of the late institutionalisation of those officials - something which affected the number and survival of all Board-related records. It was also naturally the longitude which most preoccupied projectors during the earlier decades. As the Board further expanded its interests and efforts to encompass other navigational and mathematical activities, projectors increasingly offered up purported improvements to other activities. The correspondents in this volume differed as to precisely how important it was to improve methods of finding latitude - with some like the Naval Master and navigation teacher Richard Burstal near Plymouth Dock <a href='' onclick='store.loadPage();return false;'> saying (RGO 14/41:72)</a> that it had 'hitherto been generaly [sic] too much neglected', and others like James Burns of London <a href='' onclick='store.loadPage();return false;'> saying (RGO 14/41:60)</a> that an improvement would be useful but perhaps not vital.</p><p style='text-align: justify;'>The letters regard 23 correspondents, most of whom were British, and many of those from the provinces rather than from London - including <a href='' onclick='store.loadPage();return false;'>RGO 14/41:4</a> of Whitby, <a href='' onclick='store.loadPage();return false;'>RGO 14/41:8</a> of Devon, <a href='' onclick='store.loadPage();return false;'>RGO 14/41:14</a> near Dunburton, <a href='' onclick='store.loadPage();return false;'>RGO 14/41:42</a> of the Royal Naval College, Richard Burstal and <a href='' onclick='store.loadPage();return false;'>RGO 14/41:93</a> near or at Plymouth Dock, <a href='' onclick='store.loadPage();return false;'>RGO 14/41:76</a> of Bristol, <a href='' onclick='store.loadPage();return false;'>RGO 14/41:132</a> of Edinburgh, and <a href='' onclick='store.loadPage();return false;'>RGO 14/41:185</a> near Guilford. Some of the British projectors also wrote from abroad, as when Lieutenant William Wood RN<a href='' onclick='store.loadPage();return false;'> wrote (RGO 14/41:171)</a> from Montreuil in France in 1821 about his Universal Analemma. (The <i>Analemma</i>, which Wood said had been well reviewed by men of science in France and England, was intended to solve all problems in nautical astronomy including lunar distances without calculations.)</p><p style='text-align: justify;'>The foreign correspondents in this volume include the Jesuit natural philosopher<a href='' onclick='store.loadPage();return false;'>RGO 14/41:50</a> of Bruxelle with a method of finding latitude by using double altitudes of the Sun, <a href='' onclick='store.loadPage();return false;'>RGO 14/41:181</a> writing about some nautical tables in 1827, the unnamed 'deserving' but 'necessitous' Hanoverian projector whose latitude scheme was <a href='' onclick='store.loadPage();return false;'> transmitted (RGO 14/41:157)</a> by Daniel J. Thomson in 1821 (although Hanover was then ruled by King George IV [<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 possibly the unknown author of <a href='' onclick='store.loadPage();return false;'> observations (RGO 14/41:177)</a> of the Sun's altitude near the meridian for determining latitude and then longitude for locations in Norway. José de Mendoza y R'os also <a href='' onclick='store.loadPage();return false;'> wrote (RGO 14/41:12)</a> in 1796 about his rules for computing latitude by two atitudes of the Sun, but he was settled in London by that time.</p><p style='text-align: justify;'>The correspondence in this volume exhibits a number of themes to be found across the surviving Board-related records, including the frequency with which projectors recounted sob stories when seeking financial rewards. Many of those associated with the Navy [<a target='_blank' class='externalLink' href=''><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>], who along with educators represent a significant proportion of the projectors in this volume and of longitude projectors in general, specifically mentioned their being on half pay. (Commissioned Naval officers went on half-pay when they were in-between postings rather than being let go entirely, something instituted by Samuel Pepys [<a target='_blank' class='externalLink' href=''><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>] when he was Secretary of the Navy.) For example in 1822, the Naval purser John Cole of Plymouth Dock <a href='' onclick='store.loadPage();return false;'> pleaded (RGO 14/41:116)</a> that, 'I have a family of six Children with nothing but my half pay of four Shillings per day to support them on - a Speedy decision on the subject is of very great importance to me [...] should I fail of success in my present aim I shall be under the necessity of adopting some other plan of providing for my numerous and destitute family'. (Cole proposed a method of finding latitude using the time employed in the Sun's rising and setting, which he <a href='' onclick='store.loadPage(176);return false;'> said (RGO 14/41:93v)</a> might prove of great use as ships entered the Channel or North Seas. He later <a href='' onclick='store.loadPage();return false;'> said (RGO 14/41:114)</a> that then-Lieutenant Edward Parry [<a target='_blank' class='externalLink' href=''><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>] had recorded using his plan 19 times during the voyage in which he had recently participated to seek a North-West sea passage to the Pacific.)</p><p style='text-align: justify;'>It was also common for projectors to highlight their influential connections when seeking assistance and recognition. For example, <a href='' onclick='store.loadPage();return false;'>RGO 14/41:59</a> of London referenced 'Mr. Dyer, chief clerk of the Admiralty and a particular friend', <a href='' onclick='store.loadPage();return false;'>RGO 14/41:120</a> of Camden Town referenced the noble-born Naval officers with whom he served as Master and Master of the Fleet, and <a href='' onclick='store.loadPage();return false;'>RGO 14/41:136</a> of London mentioned that two of his cousins had previously been Maids of Honour at Court when he sought any small token due to his 'forlorn' situation (one of the few times a projector cited female references). It was also noted that the Naval officer and hydrographer Captain William Fitzwilliam Owen [<a target='_blank' class='externalLink' href='!csearch;authority=agent-177387;makerReference=agent-177387'><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>] was younger brother to Sir Edward Campbell Rich Owen [<a target='_blank' class='externalLink' href=''><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>], who had distinguished himself during wartime. (In fact, the younger Owen <a href='' onclick='store.loadPage(295);return false;'> described (RGO 14/41:154v)</a> to the Board his brother's method of applying the interval of time measured by a chronometer to the correction of the latitude and longitude, as well as his own application of it to correcting the latitude through celestial observations and to correcting the longitude by chronometer.)</p><p style='text-align: justify;'>A small percentage of the letters in this volume include comments from Commissioners or from the Secretary, with additional information sometimes to be found in other volumes and in the surviving minutes. For example, the Astronomer Royal and active Commissioner 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>]<a href='' onclick='store.loadPage();return false;'> noted (RGO 14/41:8)</a> on 8 December 1787 on Philip Hannaford of Devon's description of three methods of finding latitude at sea that, 'Mr Hannaford's methods deserve not the attention of the Board'. However, most letters do not bear such annotations, and some reveal Commissioners apparently trying to avoid correspondents more than anything else. In 1823, <a href='' onclick='store.loadPage();return false;'>RGO 14/41:34</a> of London appealed to the Board at large because he had not gotten a response from or meeting with the Astronomer Royal John Pond [<a target='_blank' class='externalLink' href='!csearch;authority=agent-17444;makerReference=agent-17444'><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>] about his instrument for solving nautical problems such as finding the latitude without calculations by using celestial altitudes and declinations. However, he failed in his request to have copies of said instrument made and tested at Greenwich and on the way to the West Indies as had been other technologies.</p><p style='text-align: justify;'>Alexi Baker<br />History and Philosophy of Science<br />University of Cambridge<br /></p>

Want to know more?

Under the 'More' menu you can find , and information about sharing this image.

No Contents List Available
No Metadata Available


If you want to share this page with others you can send them a link to this individual page:
Alternatively please share this page on social media

You can also embed the viewer into your own website or blog using the code below: