A history of light and colour measurement : science in the shadows

PREFACE ix 1 INTRODUCTION: MAKING LIGHT COUNT 1 1.1 Organization of chapters 4 1.2 Terms 9 Notes 10 2 LIGHT AS A LAW-ABIDING QUANTITY 12 2.1 Beginnings 12 2.2 A lawless frontier 18 2.2.1 Photography: juggling variables 20 2.2.2 Astronomy: isolated forays 21 2.3 Techniques of visual photometry 22 2.3.1 Qualitative methods 22 2.3.2 Comparative methods 22 2.3.3 Physical methods 24 2.4 Studies of radiant heat 24 2.5 Describing colour 26 Notes 28 3 SEEING THINGS 33 3.1 Recurring themes 34 3.2 Altered perceptions 36 3.2.1 Astrophysics and the scientific measurement of light 37 3.2.2 Spectroscopy 41 3.2.3 Shifting standards: gas and electrotechnical photometry 42 3.2.4 Utilitarian connections 43 3.3 The 19th-century photometer 49 3.4 Prejudice and temptation: the problems in judging intensity 53 3.5 Quantifying light: n-rays versus blackbody radiation 58 Notes 64 4 CAREERS IN THE SHADOWS 72 4.1 Amateurs and independent research 72 4.2 The illuminating engineers 75 4.3 Optical societies 86 A History of Light and Colour Measurement Notes 88 5 LABORATORIES AND LEGISLATION 94 5.1 Utilitarian pressures 94 5.2 The Physikalisch-Technische Reichsanstalt 96 5.3 The National Physical Laboratory 99 5.4 The National Bureau of Standards 102 5.5 Colour at the national laboratories 104 5.6 Tracing careers 107 5.7 Weighing up the national laboratories 109 5.8 Industrial laboratories 111 5.9 Wartime photometry 114 5.10 Consolidation of practitioners 116 Notes 117 6 TECHNOLOGY IN TRANSITION 125 6.1 A fashion for physical photometry 125 6.1.1 Objectivity 126 6.1.2 Precision 128 6.1.3 Speed 129 6.1.4 Automation 129 6.2 The refinement of vision 130 6.3 Shifts of confidence 133 6.4 Physical photometry for astronomers 135 6.4.1 An awkward hybrid: photographic recording and visual analysis 135 6.4.2 A halfway house: photographic recording and photoelectric analysis 137 6.4.3 A ‘more troublesome’ method: direct photoelectric photometry 139 6.5 The rise of photoelectric photometry 142 6.6 Recalcitrant problems 148 6.6.1 Talbot’s law 148 6.6.2 Linearity 148 6.6.3 The spectre of heterochromatic photometry 150 Notes 151 7 DISPUTING LIGHT AND COLOUR 159 7.1 The Commission Internationale de Photom´etrie 161 7.2 The Commission Internationale de l’ ´ Eclairage 162 7.3 Legislative connections 167 7.4 Constructing colorimetry 168 7.4.1 Colour at the CIE 168 7.4.2 Disciplinary divisions 176 7.4.3 Differentiating the issues 177 7.5 Voting on colour 179 vi Contents 7.5.1 Configuring compromise 180 7.5.2 An uncertain closure 181 Notes 184 8 MARKETING PHOTOMETRY 191 8.1 Birth of an industry 192 8.2 Technological influences 194 8.3 Linking communities 197 8.3.1 Extension of commercial expertise 200 8.3.2 New practitioners 201 8.4 Making modernity 203 8.5 Backlash to commercialization 204 8.6 New instruments and new measurements 206 8.7 Photometry for the millions 208 8.8 A better image through advertising 210 Notes 213 9 MILITARIZING RADIOMETRY 220 9.1 The mystique of the invisible 220 9.2 Military connections 221 9.2.1 British research 222 9.2.2 American developments during the SecondWorld War 222 9.2.3 German experiences 224 9.2.4 Post-war perspectives 225 9.2.5 New research: beyond the n-ray 227 9.2.6 New technology 227 9.3 New centres 229 9.4 New communities 230 9.5 New units, new standards 231 9.6 Commercialization of confidential expertise 232 9.6.1 New public knowledge 232 9.7 A new balance: radiometry as the ‘senior’ specialism 233 Notes 233 10 AN ‘UNDISCIPLINED SCIENCE’ 237 10.1 Evolution of practice and technique 237 10.2 The social foundations of light 240 10.3 A peripheral science? 243 10.3.1 On being at the edge 243 10.3.2 Technique, technology or applied science? 245 10.3.3 Attributes of peripheral science 247 10.4 Epilogue: declining fortunes 248 Notes 250 BIBLIOGRAPHY 255 Abbreviations 255 Periodicals 255 vii A History of Light and Colour Measurement Organizations 257 Other 258 Sources 258 Notes 261 Bibliography 261 INDEX 272 viii