Papers of Nevil Maskelyne : Journal of voyage to Bombay

Bishop, Robert; Scott, Robert

Papers of Nevil Maskelyne

An abstract of a journal of an East Indiaman compiled by Robert Bishop, former master and pilot in the West Indies who produced charts and sailing directions for the region. It was in his capacity as pilot for this region that Bishop was examined in 1763 by a Parliamentary committee with respect to John Harrison's fourth chronometer, noted by Derek Howse in Nevil Maskelyne: Seaman's Astronomer (Cambridge, 1989). He was also appointed by the Board of Longitude in 1768 to instruct and issue certificates to masters relating to their ability to use almanac and quadrant <a href='/view/MS-RGO-00014-00005/177'> Confirmed Minutes for 12 November 1768 (RGO 14/5:173)</a> and he compiled tables for the computation of longitude, some of which are held in <a href='/view/MS-RGO-00014-00067'> Observations on Voyage of Discovery (RGO 14/67)</a>. Bishop used the journals from routine East India Company voyages to compile his East India Navigator's Daily Assistant (London, 1773), a volume of sailing directions in which journal summaries such as this are reproduced alongside textual description.This journal summary is from the 1769 to 1770 voyage of the East India Company ship Speaker from England to Bombay and the return voyage, written by the Captain, Robert Scott. Physically it is made up of four folded leaves and is approximately 23 by 30 cm in size. The summary is tabulated, with columns for recording the daily latitude and longitude 'by account', longitude corrected by observation and the difference between the tow longitude positions. A final column is for observations on magnetic variation. Remarks inserted, <a href='/view/MS-RGO-00004-00155/'> transgressing the lines of the table (RGO 4/155:3)</a>, suggest the importance of navigational information extraneous to the form here proposed for describing the ship's passage, as well as the significance of recording particular experience, not only as part of shipboard bureaucratic practice but also in subsequent texts produced for use in the field.This particular summary is partly reproduced in Bishop's East India Navigator's Daily Assistant, pp.29-33. As with the <a href='/view/MS-RGO-00004-00158'> Journal of East Indiaman Prince of Wales (RGO 4/158)</a>, in this abstract longitude corrected by lunar observation is frequently recorded. It is notable that the only interaction between the columns for longitude by account and longitude corrected by observation is shown in the difference column; the 'correction' is not applied to the series of observations of longitude by account. As a document produced during the construction of a set of sailing directions, the noting of where longitude by account differed radically from longitude by observation also potentially speaks to the importance of knowing whereabouts on a voyage longitude by account might be liable to slip.Remarks concern details of soundings including the <a href='' onclick='store.loadPage(1);return false;'> retrieval of red and white coral on the lead (RGO 4/156:2)</a>, sightings of land, and the <a href='' onclick='store.loadPage(1);return false;'> observation of blue lights (RGO 4/156:3)</a> which showed every two hours on Old Woman's Island, near to Bombay on the west coast of India.An inserted note on 15th June 1770 shows evidence of the exchange of geographical information between ships, and hence the heterogeneous nature of the collection of navigational information, in this instance a <a href='' onclick='store.loadPage(1);return false;'> 'Swedis ship who informed us that the Start Bore NW Distance 8 or 9 leagues' (RGO 4/156:4)</a>.Along with the other journal summaries compiled by Bishop (<a href='/view/MS-RGO-00004-00155'> (RGO 4/155)</a>, <a href='/view/MS-RGO-00004-00157'> (RGO 4/157)</a> and <a href='/view/MS-RGO-00004-00158'> (RGO 4/158)</a>), this volume is significant as it contains some of the data from which his East India sailing directions were constructed, and speaks to the potential use and utility of shipboard inscriptions.Megan Barford History and Philosophy of Science University of Cambridge