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Papers of the Board of Longitude : Remarks by chronometer-makers on Arnold's printed 'Explanation of Time Keepers'

Papers of the Board of Longitude

<p style='text-align: justify;'>The content of this volume relates closely to <a href='/view/MS-RGO-00014-00027'> (RGO 14/27)</a>. It contains the responses by fifteen watchmakers and 'inventors' to an account written by the watchmaker John Roger Arnold (see <a target='_blank' class='externalLink' href=''>portait</a> at the Science Museum Group). Arnold sent his 'Explanation' to the Board of Longitude at the beginning of March 1805 in response to their request for him to 'reveal' the manner in which he had constructed his timekeepers. The Board's aim in doing so was to inform the watchmaking community of Arnold's 'secrets'. They hoped this would encourage the production of other timekeepers in a similar fashion.</p><p style='text-align: justify;'>The Board of Longitude's motive in requesting John Roger Arnold to submit an explanation of the construction of his timekeepers was prompted partly by a failure to resolve a long-standing disagreement between John Roger Arnold (and his father, John Arnold (see <a target='_blank' class='externalLink' href=''>portrait</a> at the British Museum), and the watchmaker Thomas Earnshaw [<a target='_blank' class='externalLink' href=''><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>]. Both claimed to have invented, or discovered, the spring detent escapement. The disagreement had generated confusion and venom on behalf of some of its antagonists. This was largely due to John Arnold's decision to patent a design for the escapement in 1782. The best discussion of this is by Jonathan Betts, 'Arnold & Earnshaw: The Practicable Solution', The Quest for Longitude, (Harvard 1996).</p><p style='text-align: justify;'>While the Board of Longitude had no official mandate to intervene in the dispute, it had caused some problems in their deliberations over deciding the person to whom they should reward for the 'improvement to timekeepers'. In 1803, the Board had decided that Thomas Earnshaw should receive the reward, but this decision was immediately challenged by Joseph Banks [<a target='_blank' class='externalLink' href=''><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>], one of the members of the Board of Longitude and well-known patron to John Arnold. This brought about a series of trials in 1803 in which the Board called both Arnold and Earnshaw, and several other clock and watchmakers, to answer about their knowledge of who made the escapement.</p><p style='text-align: justify;'>Included in the Board's questions to those testifying in 1803 were questions relating to the production, cost and likely replicability of Arnold and Earnshaw's timekeepers. The Board's intention was to encourage the manufacture of timekeepers by other members of the watchmaking trade. The task was made more difficult for the Board, however, because of a lack of knowledge over what procedures should be regarded as more suitable for this hoped for expansion of production by the clockmaking community, and equally, who to trust in their answers to the Board. It was in a direct response to these concerns that the Board of Longitude requested from Arnold and Earnshaw their 'Explanations as well as sending them out to chosen commentators.</p><p style='text-align: justify;'>This volume contains the complete set of responses received by the Board from those commentators that they contacted between April and May 1805, with the request that they would 'suggest such questions as may tend to the better and more perfect explanation of the principles of the Timkeepers therein'. Joseph Banks and the Astronomer Royal (and member of the Board) 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>] sent out these copies of the 'Explanation'. Banks sent his out to the watchmakers William Barraud, John Brockank, William Hardy, Charles Hayley, Robert Pennington, Owen Robinson, Robert Molyneux [<a target='_blank' class='externalLink' href='!csearch;authority=agent-122843;makerReference=agent-122843'><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>], Charles Young, the mathematical instrument maker, Edward Troughton [<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 the 'journalist and inventor' William Nicholson. Maskelyne's copies were sent to watchmakers John Barwise, Peter Grimaldi, James Petto, Louis Recordon and the mathematical instrument maker [John] Grant. </p><p style='text-align: justify;'>The responses to Arnold's Explanations vary in tone and concern. Several clearly responded directly to the Board's stated request to give their opinions on the validity and clarity of the explanations. Several, however, allude to the claims for invention by Arnold, which range from either totally agreeing with Arnold - and therefore maintaining the superiority of Arnold's character and workmanship over Earnshaw's - to suggesting, like those comments by William Nicholson, that the Board will learn very little that is new from his account.</p><p style='text-align: justify;'>Eóin Phillips<br />History and Philosophy of Science<br />University of Cambridge<br /></p>

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