IV. The ('a parity for Heat of Metals at Different Temperatures, being an 

 Account of Experiments performed in the Research Laboratory of the 



i/// Cn//ii/i a/ ' Sunlli II till* a,, <l Monmouthshire. 



By E. H. GRIFFITHS, Sc.D., F.M.S., and EZER GRIFFITHS, B.Sc., Fellow of the 



University of Wales. 



Received April 1, Read May 1, 1913. 



CONTENTS. 

 Section. Page 



I. Introductory 119 



II. Outline of apparatus 122 



III. Measurement of temperature 126 



IV. Measurement of the resistance of the heating coil 131 



V. Measurement of potential difference 137 



VI. The thermal capacity of accessory substances 138 



VII. Measurement of mass 140 



VIII. Measurement of time 141 



IX. Temperature control of the baths 141 



X. Methods of experiments 



(1) Total heat 143 



(2) Intersection . ! '..'.'.'. 147 



XI. Experimental results 



(1) Cu, (2) Al, (3) Fe, (4) Zn, (5) Ag, (6) Cd, (7) Sn, (8) Pb 159 



XII. Summary of results 170 



XIII. NERNST'S observations at low temperatures 175 



APPENDIX I. Discussion of the results 178 



APPENDIX II. The relation between melting-points and atomic heats 183 



APPENDIX III. The soldering of glass and quartz tubes to metal 184 



SECTION I. 

 Introductory. 



A STUDY of the published determinations of the capacity for heat of the elements 

 leads to the conclusion that further information of an accurate nature is desirable. It 

 will be found that, in most cases, the values are deduced by observations of the heat 

 absorbed or given out when the changes of temperature are large, and the conclusions 



VOL. CCXIII. A 500. Published separately, July 28, 1913. 



