National Maritime Museum Manuscripts : Navigational workbook: collected observations and workings, 1825-1852

Fisher, George

National Maritime Museum Manuscripts

<p style='text-align: justify;'>This notebook spans most of George Fisher’s career as a Navy Chaplin and Astronomer with only his first voyage to the Arctic, with Captain Buchan on board HMS Dorothea , preceding Fisher’s use of this journal. As a result of the length of time that Fisher worked using this notebook the contents are rather eclectic; mathematical calculations for a variety of investigations into the error rates of instruments make up the volume along with astronomical observations from a variety of places, from Fisher’s <a href='' onclick='store.loadPage(4);return false;'> own window (FIS/23:2)</a> to <a href='' onclick='store.loadPage(17);return false;'> Lisbon (FIS/23:15)</a>, <a href='' onclick='store.loadPage(7);return false;'> Stansted (FIS/23:5)</a> and <a href='' onclick='store.loadPage(24);return false;'> Greenwich (FIS/23:22)</a>.</p><p style='text-align: justify;'>This notebook is essentially Fisher’s rough workbook and was used most often in the early to mid-1830s just after his retirement from the Navy. There is not a continuous or designed series of experiments or investigations recorded in this volume, but instead the odd workings out from an eclectic range of Fisher's work. For example we see a series of <a href='' onclick='store.loadPage(28);return false;'> latitude calculations (FIS/23:26)</a> from August and September 1835, then the volume jumps to March 1836 with the reduction of a <a href='' onclick='store.loadPage(36);return false;'> series of Lunars (FIS/23:34)</a> taken over the month. There is also a record of Fisher’s observations of an <a href='' onclick='store.loadPage(44);return false;'> eclipse of the sun (FIS/23:42)</a> from the 15th of May 1836. The volume is not limited to astronomical work either; there are Fisher’s notes on the <a href='' onclick='store.loadPage(43);return false;'> error rates (FIS/23:41)</a> for glass spring chronometers that he worked with in March and April of 1836. The idea of glass balances and balance springs occupied much of Fisher's thought in the 1830s after his retirement from the Navy. Fisher, prior to this set of investigations, published some of his results on the subject in <i>The Nautical Magazine</i> in 1833 suggesting that glass springs would negate the effect of magnetism on chronometers. Arnold and Dent also worked with glass as a material for chronometer construction in the early 1830s and Fisher collaborated with them periodically on this research as well as with other aspects of chronometer work, for example the ratings we see for Arnold and Dent chronometers performed by Fisher in <a href='/view/MS-FIS-00021'> (FIS/21)</a>.</p><p style='text-align: justify;'>The instruments used by Fisher across this period were made by some of the finest instrument makers of the time, for example there are <a href='' onclick='store.loadPage(22);return false;'> several pieces (FIS/23:20)</a> made by Edward Troughton in the volume. The book is also punctuated with Fisher’s illustrations, for example a series of <a href='' onclick='store.loadPage(62);return false;'> sketches (FIS/23:60)</a> of the adjustment to the field view for observations of the sun behind some chimney pots appears on pages that record and reduce the observations.</p><p style='text-align: justify;'>It would be interesting to attempt to map some of the more systematic workbooks that Fisher maintained as well as his publications onto the collection of calculations found in this volume.</p><p style='text-align: justify;'>Sophie Waring<br />History and Philosophy of Science<br />University of Cambridge<br /></p>