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Papers of the Board of Longitude : Papers regarding inventions and improvements of various astronomical and nautical instruments

Papers of the Board of Longitude

<p style='text-align: justify;'>This volume and volume <a href='/view/MS-RGO-00014-00029'> (RGO 14/29)</a> contain correspondence with and supporting evidence from British and foreign projectors who asked the Board of Longitude for rewards for their new or improved nautical and astronomical instruments and aids such as marine chairs, or for assistance with the development and trialling of these inventions. In 1858, the 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 these materials into different sections, mostly according to correspondent - 34 in this volume and 22 in volume RGO 14/29. On some papers there are notes in red summarizing the contents of documents or referring to the fate of related records, which were likely added by the final Secretary to the Board, Thomas Young (see <a target='_blank' class='externalLink' href=''>portrait</a> at the National Portrait Gallery). For example, a <a href='' onclick='store.loadPage();return false;'> note (RGO 14/30:293)</a> following a letter from January 1820 reads, 'Committee Papers Dumped April 1820'.</p><p style='text-align: justify;'>As with the materials in RGO 14 as a whole, these communications are weighted towards the final decades of the existence of the Commissioners of the Longitude because of factors including the selective survival and interpretation of records, and the increased institutionalization of the Commissioners from the 1760s on. They also do not encompass all of projectors who tried to contact the Board during the period covered, since some relevant records did not survive to this point, and some projectors were turned away by individual contacts or were met with silence rather than having achieved a bureaucratic response. A small number of the documents in this volume are not communications by projectors, but instead about projectors or their inventions. For example, there is a <a href='' onclick='store.loadPage();return false;'> note (RGO 14/30:370)</a> from the Consul's Office in Trieste in 1824 about a manuscript in German on an improved compass and instrument, which the author had requested be sent to the Board.</p><p style='text-align: justify;'>Technology like that discussed in these two volumes was vital to all of the activites to which the Board contributed, from the search for the longitude and the development of general navigational improvements, to experiments and voyages of science and exploration. In terms of the longitude, all of the main approaches deemed contenders for the rewards established in 1714 required the usage of instruments and typically of accompanying texts. For example, 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>] relied upon astronomical instruments such as the quadrant for making observations and on instructive and predictive texts to guide and accelerate the observation taking and ensuing calculations. Magnetic variation of course required compasses as well as magnetic charts and publications. For decades after the death of John Harrison [<a target='_blank' class='externalLink' href=''><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>], chronometers still needed to be used in conjunction with astronomical instruments as well. This was understood by all informed actors during the lifetime of the Commissioners, so the modern perception of there having been an unbridgeable gap between the thoughts and activities of astronomers and 'professors' like 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 of 'mechanics' like John Harrison is inaccurate.</p><p style='text-align: justify;'>One thing that the papers in this volume and in RGO 14/29 reveal is domestic and foreign projectors' methods of approaching the Board and of trying to esablish their credibility and that of their inventions, including through images and printed advertisements and explanations, trial results, patents obtained and testimonials from individuals such as navigators, astronomers and scientific instrument makers. These records also shed further light on the ways in which the Commissioners and the different Secretaries judged and interacted with these individuals, with the body's output during its final decades likely seeming more bureaucratic and organised to modern eyes than that from the earlier years. One can further see trends develop in response to changing scientific and navigational trends and interests (hence the later preponderance of compass proposals for example), and the increased mention of patents and usage of printed memorials and descriptions and of drawn or printed images. The projectors included in this volume are relatively diverse, as was typical of petitioners to the Board. They included the provincial and occasionally the foreign as well as those based in London and encompassed Naval and merchant men, a Surveyor-General and an Admiralty hydrographer, instrument makers, professors and tutors, inventors, and gentlemen. The professors included <a href='' onclick='store.loadPage();return false;'>RGO 14/30:455</a>, Professor and Director of Navigation at Copenhagen, who wrote in 1789 about his sea telescope and provided a number of drawings of it.</p><p style='text-align: justify;'>The projectors did not always contact the Board of Longitude directly but instead sometimes asked an individual or institutional go-between to transmit their communications, or in fact only intended to contact another organisation such as the Admiralty, which later decided to pass the matter on to the Board instead. This sometimes occurred after the institution in question had first conducted its own consultations and experiments. The inventions and innovations described in this volume mainly regard telescopes for use at sea, compasses, and quadrants and sextants [<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 other instruments for making observations. The more atypical include a sliding rule, a marine chair, fluid lenses for telescopes, a goniometer, and improvements to the dividing engine for the precision marking of scales on 'scientific' instruments. The marine chair harkened back to that of Christopher Irwin of Ireland, who received £500 from the Commissioners on <a href='/view/MS-RGO-00014-00005/41'> 17 August 1762 (RGO 14/5:37)</a> for perfecting and testing his own design. The later chair was designed by <a href='' onclick='store.loadPage();return false;'>RGO 14/30:470</a>, who tested it on a voyage to China in 1793-1794 and then wrote to the Board about it in 1796-1797 and then again in 1817.</p><p style='text-align: justify;'>Some of the projectors in the volume were successful in the sense of having obtained rewards or grants for research and development (most comparatively small) or additional work with the Commissioners -- testing and improving other technologies or contributing to the Board's 'scientific' efforts -- while other projectors were ultimately turned away or rejected outright. One of the more successful projectors who appears in this volume was Peter Barlow, who wrote in 1828, shortly before the abolition of the Board, <a href='' onclick='store.loadPage();return false;'> about his fluid lenses for telescopes (RGO 14/30:388)</a>. Barlow, who was Professor of Mathematics at the Royal Military Academy in Woolwich had previously been granted £500 by the Commissioners in 1824 for his attempts at offsetting the effect which the increased presence of steel in ships had on compasses. His work on fluid lenses would be encouraged by the Royal Society after the abolition of the Board. Additional materials relevant to Barlow and to some of the other projectors in this volume can be found in other locations in the archive as well, including in other correspondence and of course in the minutes and accounts.</p><p style='text-align: justify;'>Alexi Baker<br />History and Philosophy of Science<br />University of Cambridge<br /></p>

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