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VI. On the Specific Heats of Air and Carbon Dioxide at Atmospheric Pressure 

 by the Continuous Electric Method at 20 C. and 1 00 C. 



(Experiments performed in the Physical Laboratory of the Royal College of Science, 



London, S. W.) 



By W. F. G. SWANN, A.R.C.S., B.Sc., Assistant Lecturer in Physics 



at Sheffield University. 



Communicated ly Prof. H. L. CALLENDAR, M.A., F.R.S. 



Keceived October 8, Read December 10, 1908, Received in condensed form 



November 13, 1909. 



TABLE OF CONTENTS. 



Section Page 



(1) Introduction 200 



(2) Outline of the method 200 



(3) Measurement of the electrical energy 202 



(4) The continuous flow electrical calorimeter 203 



(5) The platinum thermometers and heating coil 203 



(6) The platinum thermometer bridge and the measurement of the fundamental intervals . . 204 



(7) The cadmium cells 20G 



(8) The potentiometer 207 



(9) The secondary standard resistance 207 



(10) The pressure regulator 208 



(11) The oil gauge 208 



(12) The preliminary experiments 210 



(13) Theoretical consideration of the variation of the heat loss with the flow 211 



(14) The final experiments 216 



(15) Calibration of the fine metal tubes for air 216 



(16) Calculation of the results for the calibration of the fine tubes 220 



(17) Abridged tables for the calibration of the fine tubes for air 221 



(18) The main calorimetric experiments 222 



(19) The heating effect of the current leads 223 



(20) Calculation of the results 224 



(21) Abridged tables for the main calorimetric experiments on air 226 



(22) Comparison of the results for air with the theoretical value 230 



(23) Criticism of previous results 231 



VOL. CCX. A 464. 29.3.10 



