4 CONTENTS. 



Part VII. Infra-red Emission Spectra. Continued. r, 



Page 



Chapter II. Selective radiation from various solids 93-132 



Introduction 93 - 6 



Radiation from electrically heated solids 96-1 1 1 



Emission spectra of solids on Nernst "heater tube" 111-124 



Relation between emissivity and energy consumption 1 24-1 29 



Summary 129-132 



Chapter III. Radiation from selectively reflecting bodies, with special reference to 



the moon 133-146 



The effective temperature of the sun 133135 



The limiting temperature of the surface of the moon 135 



Fall of temperature of the moon during eclipse 136-137 



Reflection and radiation from the moon 138-139 



Emission from a partial radiator 140-146 



Appendix I: The effect of the surrounding medium upon the emissivity of a sub- 

 stance i47 - i 5 1 



Appendix II: Instruments and methods used in radiometry 152-176 



I. The microradiometer 153 



II. The radiomicrometer 153155 



III. The thermopile 155-158 



Comparison of old and new form of thermopile 156-157 



The Peltier effect 157-158 



IV. The radiometer 158-165 



Comparison of sensitiveness and area of vane 159-160 



Comparison of sensitiveness and diameter of fiber suspension 160-162 



Sensitiveness compared with wave-length of exciting source 162-163 



The radiometer compared with the bolometer 163-165 



V. The bolometer with its auxiliary galvanometer 165-175 



Historical 165-169 



Comparison of sensitiveness of various bolometer-galvanometer combi- 

 nations, 170 



Comparison of a bolometer with a thermopile 170-172 



Experiment with a sectored disk 172-175 



VI. Summary 175-176 



Appendix III: Additional data on selective reflection as a function of the atomic 



weight of the base 177-180 



Addendum 181-182 



Index of substances 183 



