National Maritime Museum Manuscripts : Navigational workbook: workings of chronometers, Greenwich(?) and New York

National Maritime Museum Manuscripts

<p>After time spent as an astronomer on two Arctic voyages, the first with <a href='/search?keyword=David%20Buchan'>David Buchan</a> on board <a href='/search?keyword=HMS%20Dorothea'> <i>HMS Dorothea</i> </a> in 1818, the second with <a href='/search?keyword=William%20Parry'>William Parry</a> in 1821 on <a href='/search?keyword=HMS%20Fury'> <i>HMS Fury</i> </a> seeking the <a href='/search?keyword=North%20West%20Passage'>North West Passage</a>, as well as several expeditions to the warmer climes of the <a href='/search?keyword=Mediterranean'>Mediterranean</a> aboard the <a href='/search?keyword=HMS%20Asia'> <i>HMS Asia</i> </a> in 1831, <a href='/search?keyword=George%20Fisher'>George Fisher</a> retired from the Navy on half pay in 1834. Fisher took up the headship of the Royal Hospital School in <a href='/search?keyword=Greenwich'>Greenwich</a> where he continued his academic interest in causes of variation in the rates of chronometers whilst planning and overseeing the construction of the school’s observatory.</p> <p>This particular notebook is part of his work in this period at the end of the 1830s. It is concerned with the effect of different environmental conditions on the rate of chronometers, continuing from experiments conducted whilst on active service. There is data [<a href='' onclick='store.loadPage(4);return false;'>1-9</a>] collected regarding the effect of ‘suspending’ and ‘clamping’ a chronometer and the effect [<a href='' onclick='store.loadPage(13);return false;'>10</a>] of placing the chronometer on a pad of wool. There is also data [<a href='' onclick='store.loadPage(19);return false;'>16</a>] for fluctuations in temperatures which was a variable Fisher had also previously studied in the Arctic. These experiments were conducted at ‘the observatory’ and given Fisher’s locality to Greenwich at the Royal Hospital School we can presume that this work was done at the <a href='/search?keyword=Royal%20Observatory'>Royal Observatory</a> where he periodically assisted the Astronomer Royal, notably with the Observatory’s recording of the Solar Eclipse of the 8th of October 1847. This notebook serves to remind us of the maintenance required to keep a chronometer functioning even in this later period of the mid nineteenth-century and the constant demand for improved accuracy and precision.</p> <p>Also within this volume there is evidence of Fisher having travelled to <a href='/search?keyword=New%20York'>New York</a>, perhaps more than once, and collected data [<a href='' onclick='store.loadPage(25);return false;'>22</a>] there during 1839 and 1840 for comparison with Greenwich. Also Fisher compared [<a href='' onclick='store.loadPage(38);return false;'>35</a>] the rates of the chronometers that he had been working with in New York as soon as he returned to England as well as before [<a href='' onclick='store.loadPage(50);return false;'>47</a>] he left England. This is accompanied by extensive calculations for the longitude of New York City [<a href='' onclick='store.loadPage(45);return false;'>42</a>], focused on a point in Brooklyn which was 4700 feet East of the New York City Hall. There is also longer term experimental data recorded in this workbook: Fisher took the mean month rate of a clock made by <a href='/search?keyword=John%20Roger%20Arnold'>John Roger Arnold</a> and <a href='/search?keyword=Edward%20John%20Dent'>Edward John Dent</a> with a ‘mercurial comparison’ for the whole of 1838 and 1839. The varied collection of data found in this workbook is not accompanied by any conclusions, there is little text with the volume comprising mostly page after page of figures and sums, implying that this notebook was perhaps one of a collection of books that Fisher maintained simultaneously with others from this period, perhaps containing more prose.</p> <p>Sophie Waring<br />History and Philosophy of Science<br />University of Cambridge<br /> </p>


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