Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne The Development of Tide Prediction Machines Helen Mair Rawsthorne Master’s student François Viète Centre of Epistemology and the History of Science and Technology University of Western Brittany, France Doodson-Légé tide prediction machine, built in London in 1950. Photograph taken by H. M. Rawsthorne at NOC, Liverpool, on 15/01/2019; licensed under CC BY 4.0. Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne 2 2 coastal dwelling fishing marine navigation operating portsoperating docks operating harbours coastal surveyingcoastal zone engineering beachgoing watersports houseboat livingcommercial shipping naval operations building flood defences biology ecology tidal power weather forecasting Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne 3 Tidal theory, analysis and prediction ● BCE: Indian and Arabic civilisations recognising link between moon and tides ● Middle Ages: rule-of-thumb methods linked to phases of moon ● Tidal theories: Copernicus, Bacon, Galilei, Kepler, Descartes, Newton, Laplace ● Tidal analysis and prediction: Lubbock, Young, Airy, Thomson, Ferrel, Darwin, Proudman, Doodson 3 Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne 4 The development of tide prediction machines ● Mid-19th century: commercial shipping lines calling for improved prediction service ● Calculations by hand no longer sufficient ● BAAS funded development of a machine to calculate tidal predictions ● First TPM designed by William Thomson, constructed in 1873 by A. Légé & Co. in London 4 British Tide Predictor No.1, built in London in 1873. Photograph taken by H. M. Rawsthorne at Science Museum, London, on 02/02/2019; licensed under CC BY 4.0. Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne What are tide prediction machines? ● Analogue computers used for calculating tidal predictions ● Outputs: times and heights of high and low tide ● Based on tidal theory and tidal equation ● Total of 33 ever built ● Used across the world ● Always operated on land ● Superseded by digital computers 55 Doodson-Légé tide prediction machine, built in London in 1950. Photograph taken by H. M. Rawsthorne at NOC, Liverpool, on 15/01/2019; licensed under CC BY 4.0. 6 http://www.youtube.com/watch?v=Li2zhg_E3Vc Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne Significance of tide prediction machines ● Required development of scientific theory and of technology ● Crucial to advancement of marine transport: commercial and military ● Used for WWII Normandy landing operations ● Important for building modern ports and effective flood defences Bidston-Kelvin tide prediction machine, built in Glasgow in 1925. Photograph taken by H. M. Rawsthorne at SHOM, Brest, on 18/12/2018; licensed under CC BY 4.0. 77 Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne 8 Local impact of tide prediction machines ● Contributions of Joseph Proudman and Arthur Doodson ● Proudman, Doodson and LOTI: worldwide reputation for tidal research and prediction ● Two tide prediction machines on display at National Oceanography Centre, Liverpool 8 Bidston Observatory, Wirral Peninsula, Merseyside, built in 1866. Photograph taken by H. M. Rawsthorne on 08/01/2019; licensed under CC BY 4.0. PROSOPOGRAPHY Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne What is prosopography? ● Research approach usually used by historians to study the lives of groups of people ● Involves creating collective biography or gathering data about common aspects of lives of individuals within group ● Data can be compared, synthesised and analysed Define group of people to be studied Construct hypotheses and questions about group Translate hypotheses and questions into questionnaire Use authoritative sources to answer questionnaire for every member of group Create database of answers Analyse data in database to answer initial questions 1010 Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne 11 What is digital humanities? ● Interdisciplinary area of study between humanities and digital technology ● DH digital technologies come in form of tools, applications and software (purpose-built for DH or not) DIGITAL TECHNOLOGIES THE HUMANITIES to ask questions about and to create new knowledge in to ask questions of and reflect upon 11 Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne 12 Tide prediction machines, prosopography and digital humanities: how do they fit together? ● Want to study “lives” of tide prediction machines as a collection of artefacts ● Going to adapt prosopography for study of artefacts ● Going to make use of digital humanities tools for data analysis 12 Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne 13 Adaptation of prosopography ● Analogy between life of a person and existence of an artefact ● Each has a unique story to tell and is impacted by events and relations ● Can prosopography be successfully applied to study the “lives” of groups of artefacts? Define group of artefacts to be studied Construct hypotheses and questions about group Translate hypotheses and questions into questionnaire Use authoritative sources to answer questionnaire for every member of group Create database of answers Analyse data in database to answer initial questions 13 14 15 Graph showing variation of number of initial components built in tide prediction machines over time. Made by H. M. Rawsthorne using Numbers. 16 Map showing links between manufacture location (purple) and operation location (red) of tide prediction machines. Made by H. M. Rawsthorne using Palladio. 17 Year manufacture began Year decommissioned Timespan showing dates of manufacture (bottom) and dates of decommissioning (top) of tide prediction machines worldwide. Line gradient represents length of lifetime. Made by H. M. Rawsthorne using Palladio. 18 Timeline showing number of tide prediction machines that were finished being built each year worldwide. Made by H. M. Rawsthorne using Palladio. Year manufacture ended N um ber of m achines 19 Timeline showing life events of all tide prediction machines manufactured in Great Britain. Made by H. M. Rawsthorne using Time.Graphics. Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne 20 Results and evaluation ● Successful ● Larger group needed ● Need to test with different type of artefact ● Digital humanities tools essential ● Analysis of life-cycle ● How machine build changed over time ● How foreign relations impacted exportation of machines ● Shaped by the sea Tide prediction machines Artefact prosopography 20 Shaped by the Sea, Manchester, 27-28 June 2019Helen Mair Rawsthorne @hmrawsthorne 21 Bibliography Cartwright, David. Tides. Cambridge: Cambridge University Press, 2000. K. Verboven, M. Carlier & J. Dumolyn. A short manual to the art of prosopography, in: K. Keats-Rohan (ed.), Prosopography Approaches and Applications. A Handbook. Oxford: Unit for Prosopographical Research (Linacre College), 2007, p. 35-69. Woodworth, Phillip. An inventory of tide prediction machines. Southampton: National Oceanography Centre, 2016. 21