Papers of Nevil Maskelyne : 'An Account of the going of Dr Maskelyne's new Chronometer N.309 made by Mr T. Earnshaw'
Maskelyne, Nevil
Papers of Nevil Maskelyne
<p style='text-align: justify;'>The record made from trials of the going of the watchmaker Thomas Earnshaw's chronometer, No. 309, at the Royal Observatory at Greenwich at intervals between February 1800 and April 1811. Though at first glance this volume might appear less controversial than many of the letters and records written by Thomas Earnshaw in the Board of Longitude archives which characterised the tone of the 'Arnold and Earnshaw controversy' (see <a href='/view/MS-RGO-00014-00026'> (RGO 14/26)</a> and <a href='/view/MS-RGO-00014-00027'> (RGO 14/27)</a>, it in fact represents a crucial and highly contested period in the history of the Board of Longitude whereby the claims and standards of the Royal Observatory (represented by the Astronomer Royal Nevil Maskelyne) were challenged and called to question by other members of the Board of Longitude who most notably included the gentlemanly botanist Sir Joseph Banks.</p><p style='text-align: justify;'>The reason why this document can be argued to have been situated within a controversy is that the records of the going of Earnshaw's timekeeper No. 309 [<a target='_blank' class='externalLink' href='http://collections.rmg.co.uk/collections/objects/534679.html'><img title="Link to RMG" alt='RMG icon' class='nmm_icon' src='/images/general/nmm_small.png'/></a>] were put forward as crucial evidence supporting Nevil Maskelyne's claims for Thomas Earnshaw to be offered a reward of £3000 by the Board of Longitude on 3 March 1803. While the Board on that day agreed to grant Earnshaw an award for that amount in recognition of the quality of his timekeepers, it was followed by a series of protests from some leading figures of London's philosophical elite, claiming that Earnshaw was in fact not entitled to the reward. Chief among these figures was Joseph Banks, a long supporter of the watchmaker John Arnold (and his son John Roger Arnold), and veteran opponent in the hotly contested debates between 'mathematicians' and gentlemanly philosophers - perhaps the most famous example of this opposition happened at the Royal Society during 1784, when Banks and fellow gentlemen were accused by the Society's mathematicians of having no knowledge or interest in the value of practical mathematics, leading to what has been dubbed by the Historian of Science John Heilbron as 'the mathematicians mutiny' where the Society's 'mathematicians', including Nevil Maskleyne, attempted to depose Banks as President of the Royal Society. Indeed, in his Protest Against A Vote of the Board of Longitude, Granting to Mr. Earnshaw a reward for the merit of his time-keepers (1804) he aimed his attack not just at what he saw as the deficiencies in the claims of invention by Earnshaw, but importantly, on the authority of the Royal Observatory at Greenwich to decisively evaluate the going of a timekeeper. As part of his claim, Banks drew upon trials from other 'private' observatories, from which he claimed that the superiority of Earnshaw's timekeepers could be called into question. In response to this damning assessment of the quality of the regime at the Royal Observatory at Greenwich for producing reliable and trustworthy results, Nevil Maskleyne published his own list of arguments in favour of Earnshaw, and addressing some of the claims made by Banks. Of the trials taking place at Greenwich, Maskelyne stated that he believed 'most people will think that such trials are preferable to, and carry more weight and conviction with them, on many accounts, than those made at private observatories'. This 'weight and conviction', however, was something that Maskelyne needed to constantly promote, rather than simply presume, and which can be seen in relation to many of Maskelynes activities in this period, particularly his endeavour to place astronomers on voyages of discovery in this period.</p><p style='text-align: justify;'> Between 1803 and 1806, the Board of Longitude spent a considerable amount of time trying to determine the standards by which clock and watch makers such as Arnold and Earnshaw should be entitled to a reward from the Board. Often missing from accounts of this period of dispute is the other layer of contestation that existed between Maskelyne and Banks over the authority of the Royal Observatory at Greenwich to make crucial judgments on the quality of timekeepers. In this way, the rows of data in this volume should be seen not simply as evidence in the history of the timekeeper, but equally as part of the contested history that existed between institutionalised observational astronomy and the claims of gentlemanly philosophers which carried through the late eighteenth and well into the nineteenth century.</p><p style='text-align: justify;'>Eóin Phillips<br />History and Philosophy of Science<br />University of Cambridge<br /></p>